Nonlinear optical chromophore containing an adamantane group

Abstract

Nonlinear optical chromophores having one or more adamantane groups covalently attached to the chromophore, methods for preparing nonlinear optical chromophores, their use in thin films, and electro-optical devices containing such nonlinear optical chromophores and thin films containing them. Exemplary compounds are, for example, #imgabs0#

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 044,057, filed on June 25, 2020, which is hereby incorporated by reference in its entirety. Background Art

[0003] Nonlinear optical (NLO) chromophores provide electro-optic (EO) activity in polarized electro-optic polymer devices. For many years, electro-optic polymers have been studied as alternatives to inorganic materials such as lithium niobate in electro-optic devices. Electro-optic devices can include external modulators for telecommunications, RF optoelectronics, and optical interconnects, among others. Polymer electro-optic materials have demonstrated great potential for core applications in a wide range of next-generation systems and devices, including phased array radars, satellite and fiber-optic communications, cable television (CATV), optical gyroscopes for air and missile guidance, electronic countermeasures (ECM) systems, backplane interconnects for high-speed computing, ultra-fast analog-to-digital conversion, mine detection, RF optoelectronics, spatial light modulation, and all-optical (optically switched light) signal processing.

[0004] Many NLO molecules (chromophores) have been synthesized that exhibit high molecular electro-optical properties. Because dipoles are involved in material processing, the product of a molecule's dipole moment (μ) and its hyperpolarizability (β) is often used as a measure of its electro-optical performance. See Dalton et al., "New Class of High Hyperpolarizability Organic Chromophores and Process for Synthesizing the Same," WO 00 / 09613.

[0005] However, the conversion of microscopic molecular hyperpolarizability (β) into macroscopic material hyperpolarizability (χ 2 ) have encountered great difficulties. Molecular subcomponents (chromophores) must be integrated into NLO materials that exhibit (i) high macroscopic nonlinearity and (ii) sufficient temporal, thermal, chemical, and photochemical stability. High electro-optical activity and the stability of the electro-optical activity, also known as "temporal stability", are important for commercially viable devices. The electro-optical activity in electro-optic polymers can be increased by increasing the concentration of nonlinear optical chromophores in the host polymer and by increasing the electro-optical properties of the chromophores. However, some techniques for increasing the chromophore concentration can reduce the temporal stability. Solving these dual problems simultaneously is considered the ultimate obstacle to the widespread commercialization of EO polymers in many devices and systems.

[0006] High material hyperpolarizability (χ 2) is limited by the poor social properties of NLO chromophores. Commercially viable materials must incorporate chromophores with large molecular density and possessing the necessary molecular moments statistically oriented along a single material axis. To achieve such an organization, the charge transfer (dipole) properties of NLO chromophores are typically exploited by applying an external electric field during material processing, thereby generating localized low-energy conditions that favor noncentrosymmetric orders. Unfortunately, even at modest chromophore densities, molecules form multimolecular dipolar-bound (centrosymmetric) aggregates that cannot be resolved by realistic field energies. To overcome this difficulty, the integration of antisocial dipolar chromophores into cooperative material architectures is often achieved by constructing physical barriers that restrict proximal intermolecular associations.

[0007] However, the most daunting problem in the production of commercially successful NLO polymers is the long-term stability of the resulting materials. This is likely due to the reestablishment of centrosymmetry over time due to molecular mobility. The effectiveness of organic NLO materials with high hyperpolarizabilities is limited by their tendency to aggregate during processing and the thermal stability of the resulting materials. Therefore, there is a need for improved nonlinear optically active materials that have large hyperpolarizabilities and exhibit large electro-optic coefficients and high thermal stability when used in electro-optical devices. Summary of the Invention

[0008] In general, the present invention relates to nonlinear optical chromophores, methods for preparing nonlinear optical chromophores, their use in thin films, and electro-optical devices containing such nonlinear optical chromophores and thin films containing them. Therefore, various embodiments of the present invention provide such nonlinear optical chromophores, wherein the nonlinear optical chromophores have one or more diamondoid groups covalently attached to the chromophores. Various embodiments of the present invention provide such nonlinear optical chromophores, wherein the nonlinear optical chromophores have one or more diamondoid groups covalently attached to the chromophores, wherein the chromophores exhibit high molecular electro-optical properties and excellent stability. Various embodiments of the present invention provide such nonlinear optical chromophores, wherein the nonlinear optical chromophores have one or more diamondoid groups covalently attached to the chromophores, wherein the chromophores exhibit long-term stability of macroscopic electro-optical properties and minimize aggregation of chromophore molecules when the chromophores are dispersed in a host polymer matrix and polarized. Various embodiments of the present invention provide nonlinear optical chromophores having one or more adamantyl groups covalently attached to the chromophore that can exhibit improved polarization efficiency when the chromophore is dispersed in a host polymer matrix and polarized. Various embodiments of the present invention provide nonlinear optical chromophores having one or more adamantyl groups covalently attached to the chromophore that can exhibit increased loading when the chromophore is dispersed in a host polymer matrix.

[0009] Various embodiments of the present invention include nonlinear optical chromophores of formula (I):

[0010] D-Π-A (I)

[0011] wherein D represents an organic electron-donating group; A represents an organic electron-accepting group having an electron affinity greater than that of D; and π represents a π-bridge between A and D; wherein at least one adamantane is covalently linked to the nonlinear optical chromophore.

[0012] Various other embodiments of the present invention include electro-optical films comprising a nonlinear optical chromophore according to any of the preceding embodiments dispersed and polarized within a host polymer matrix. Still other embodiments of the present invention include electro-optical devices comprising an electro-optical film according to any of the preceding embodiments. Various other embodiments of the present invention include methods comprising synthesizing a nonlinear optical chromophore of formula (I):

[0013] D-Π-A (I)

[0014] wherein D represents an organic electron-donating group; A represents an organic electron-accepting group having an electron affinity greater than that of D; and π represents a π-bridge between A and D; and at least one adamantane group is covalently linked to the nonlinear optical chromophore during synthesis.

[0015] In various embodiments of the present invention, the nonlinear optical chromophore of formula (I) has a maximum of five adamantyl groups covalently attached to the structure. In various preferred embodiments of the present invention, the nonlinear optical chromophore of formula (I) has one, two or three adamantyl groups covalently attached to the structure. In various preferred embodiments of the present invention, the nonlinear optical chromophore of formula (I) has one, two or three adamantyl groups covalently attached to the structure, which adamantyl groups may be bound to the π-bridge. In various preferred embodiments of the present invention, the nonlinear optical chromophore of formula (I) has one, two or three adamantyl groups covalently attached to the structure, which adamantyl groups may be bound to D, A or the π-bridge. In various preferred embodiments of the present invention, one or more adamantyl groups are covalently attached to D or the π-bridge.

[0016] In various preferred embodiments of the present invention, at least one adamantane comprises an adamantyl group. In various preferred embodiments of the present invention, at least one adamantane comprises a diadamantyl group. In various preferred embodiments of the present invention, wherein the nonlinear optical chromophore of formula (I) has a maximum of five adamantane groups covalently attached to the structure, and in various preferred embodiments of the present invention, all of the adamantanes may be identical.

[0017] Other aspects, features and advantages will be apparent from the following disclosure, including the detailed description, preferred embodiments and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The foregoing summary of the invention, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the invention, there are shown in the accompanying drawings presently preferred embodiments. However, it should be understood that the invention is not limited to the precise arrangements and instrumentalities shown.

[0019] In the attached figure:

[0020] Figure 1 is a graphical representation of the temporal thermal stability of a thin film coating prepared using the chromophore of Synthesis Example 1; and

[0021] Figure 2 is a graphical representation of the temporal thermal stability of a thin film coating prepared using the chromophore of Synthesis Example 2. DETAILED DESCRIPTION

[0022] As used herein, unless language and / or context clearly indicate otherwise, the singular terms "a" and "the" are synonymous and are used interchangeably with "one or more" and "at least one". Thus, for example, reference to "a polymer" or "the polymer" herein or in the appended claims may refer to a single polymer or more than one polymer. As another example, and not limited to electron-donating groups, reference to "an electron-donating group" or "the electron-donating group" herein or in the appended claims may refer to a single electron-donating group or more than one electron-donating group (e.g., "D" in any molecular formula herein may represent two or more electron-donating groups that are all bound to a π-bridge). In addition, unless otherwise specifically stated, all numerical values are understood to be modified by the word "about".

[0023] As used herein, the term "nonlinear optical chromophore" (NLOC) refers to a molecule or portion of a molecule that produces a nonlinear optical effect when illuminated with light. A chromophore is any molecular unit that interacts with light to produce a nonlinear optical effect. The desired effect can occur at resonant or off-resonant wavelengths. The activity of a particular chromophore in a nonlinear optical material is expressed in terms of its hyperpolarizability, which is directly related to the molecular dipole moment of the chromophore. Various embodiments of the NLO chromophores of the present invention are useful structures for producing the NLO effect.

[0024] The first-order hyperpolarisability (β) is one of the most common and useful NLO properties. High-order hyperpolarisability is useful in other applications such as all-optical (photo-switching) applications. To determine whether a material such as a compound or polymer contains a first-order hyperpolarisable property and a sufficient electro-optic coefficient (r 33 For nonlinear optical chromophores with a specific electro-optic coefficient (β) (where the electro-optic coefficient is a function of β), the following test can be performed. First, the material in thin film form is placed in an electric field to align the dipoles. For example, this can be done by sandwiching a thin film of material, such as an indium tin oxide (ITO) substrate, a thin film of gold, or a thin film of silver, between electrodes.

[0025] Then, to generate the polarization field, an electric potential is applied to the electrodes while the material is heated to near its glass transition (T g ) temperature. After a suitable period of time, the temperature is gradually lowered while maintaining the polarizing electric field. Alternatively, the material can be polarized by corona poling, in which a charged needle at a suitable distance from the material film provides the polarizing electric field. In either case, the dipoles in the material tend to align with the field.

[0026] The nonlinear optical properties of the polarized material are then tested as described below. Polarized light, typically from a laser, is passed through the polarized material and then through a polarizing filter to a light intensity detector. If the intensity of the light received by the detector varies as a function of the potential applied to the electrodes, then the material is doped with a nonlinear optical chromophore and has an electro-optically variable refractive index. A more detailed discussion of techniques for measuring the electro-optical constants of polarized films doped with nonlinear optical chromophores can be found in Chia-Chi Teng, Measuring Electro-Optic Constants of a Poled Film, in Nonlinear Optics of Organic Molecules and Polymers, Chapter 7, 447-49 (Hari Singh Nalwa & Seizo Miyata, eds., 1997), which is incorporated by reference in its entirety, except in the case of disclosures or definitions that are inconsistent with the present application, in which case the disclosures or definitions herein shall be deemed valid.

[0027] The relationship between the applied potential change and the refractive index change of the materials can be expressed in terms of their EO coefficients r 33 This effect is often referred to as the electro-optic effect or EO effect. Devices that include materials that change their refractive index in response to changes in an applied electric potential are called electro-optic (EO) devices.

[0028] Second-order hyperpolarizability (γ) or third-order susceptibility (χ (3) ) is a standard measure of third-order NLO activity. Although there are several methods for measuring these properties, degenerate four-wave mixing (DFWM) is very common. See CW Thiel, "For-wave Mixing and Its Applications," http: / / www.physics.montana.edu.students.th iel.docs / FWMixing.pdf , the entire contents of which are hereby incorporated by reference herein. Referring to published U.S. patent application number US 2012 / 0267583A1, the entire contents of which are hereby incorporated by reference herein, a method for evaluating third-order NLO properties of thin films can be used, which is known in the art as degenerate four-wave mixing (DFWM). In Figure 4 of US2012 / 0267583A1, beams 1 and 2 are picosecond coherent pulses that are absorbed by an NLO thin film deposited on a glass substrate. Beam 3 is a weaker, slightly delayed beam with the same wavelength as beams 1 and 2. Beam 4 is the product of wave mixing, diffracted by a transient holographic grating, resulting from the interference of beams 1 and 2 in the NLO material of the thin film. Beam 3 can be a "control" beam at a telecommunications wavelength that produces a "signal" beam of a certain frequency that is not absorbed by the NLO material.

[0029] The nonlinear optical chromophore according to various embodiments of the present invention has the general formula (I):

[0030] D-Π-A (I)

[0031] wherein D represents an organic electron-donating group; A represents an organic electron-accepting group having an electron affinity greater than that of D; and Pi represents a Pi-bridge between A and D. The terms electron-donating group (donor or "D"), Pi-bridge (bridging group or "Pi"), and electron-accepting group (acceptor or "A"), as well as general synthetic methods for forming D-Pi-A chromophores, are known in the art, for example, as described in U.S. Patent Nos. 5,670,091, 5,679,763, 6,090,332, and 6,716,995, each of which is incorporated herein by reference in its entirety.

[0032] Acceptor is an atom or atom group with a low reduction potential, wherein the atom or atom group can accept electrons from a donor through a π-bridge. Acceptor (A) has a higher electron affinity than a donor (D), so that, at least in the absence of an external electric field, the chromophore is usually polarized in the ground state, and the electron density on the acceptor is relatively high (D). Typically, the acceptor group contains at least one electronegative heteroatom as a π bond (double or triple bond) part, so that the electron pair of the π bond can be formed to move to the heteroatom and simultaneously reduce the multiplicity of the π bond (i.e., the double bond is formally converted to a single bond or the triple bond is formally converted to a double bond) resonance structure, so that the heteroatom obtains a formal negative charge. The heteroatom can be part of a heterocycle. Exemplary acceptor groups include but are not limited to –NO2, –CN, –CHO, COR, CO2R, –PO(OR)3, –SOR, –SOR and –SOR, wherein R is an alkyl, aryl or heteroaryl group. The total number of heteroatoms and carbons in the acceptor group is about 30, and the acceptor group may be further substituted with alkyl, aryl, and / or heteroaryl groups.

[0033] Suitable electron accepting groups "A" (also referred to in the literature as electron withdrawing groups) for use in nonlinear optical chromophores according to various embodiments of the present invention include those described in the following published U.S. patent applications: US 2007 / 0260062; US 2007 / 0260063; US 2008 / 0009620; US 2008 / 0139812; US 2009 / 0005561; US 2012 / 0267583A1 (collectively, "Prior Publications"), each of which is incorporated herein by reference in its entirety; and those described in the following U.S. Patent Nos.: 6,584,266; 6,393,190; 6,448,416; 6,448,483; 6,514,434; 5,044,725; 4 ,795,664; 5,247,042; 5,196,509; 4,810,338; 4,936,645; 4,767,169; 5,326,661; 5,187,234; 5,170,461; 5,133,037; 5,106,211; and 5,006,285; each of which is also incorporated herein by reference in its entirety.

[0034] Among the nonlinear optical chromophores according to various preferred embodiments of the present invention, suitable electron-accepting groups include those according to the general formula (I a )

[0035]

[0036] where R 2 and R 3 Each independently represents a moiety selected from the group consisting of: H, substituted or unsubstituted C1-C 10 Alkyl, substituted or unsubstituted C2-C 10 Alkenyl, substituted or unsubstituted C2-C 10 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted alkylaryl, substituted or unsubstituted carbocycle, substituted or unsubstituted heterocycle, substituted or unsubstituted cyclohexyl and (CH2) n -O-(CH2) n , wherein n is 1-10. As used herein, Indicates a point of bonding to another part of a larger molecular structure. In preferred embodiments, R 2 and R 3 One or both of represents a halogen-substituted moiety. Halogen substitution may refer to mono-, di-, tri- and higher degrees of substitution. In various preferred embodiments, R 2 and R 3One of them represents a halogen-substituted alkyl moiety and the other represents an aromatic moiety. In various preferred embodiments, R 2 and R 3 One of them represents a halogen-substituted aromatic moiety and the other represents an alkyl moiety. In preferred embodiments, the electron accepting group may be

[0037]

[0038] In various preferred embodiments, the electron accepting group may be

[0039]

[0040] In various preferred embodiments, the electron accepting group may be

[0041]

[0042] Donor includes an atom or atom group with low oxidation potential, wherein the atom or atom group can provide electrons for acceptor " A " by π-bridge. Donor (D) has an electron affinity lower than acceptor (A), and therefore, at least in the absence of an external electric field, chromophore is typically polarized, and the electron density on donor (D) is relatively low. Usually, donor group contains at least one heteroatom, and the heteroatom has a lone pair of electrons that can be conjugated with the p orbital of the atom directly connected to the heteroatom, therefore the key for making the lone pair of electrons move to the p orbital with the atom directly connected to the heteroatom can be formed, to formally increase the multiplicity (that is, singly bond is formally converted to double bond or double bond is formally converted to triple bond) resonance structure of the bond between the heteroatom and the atom directly connected to the heteroatom, so that heteroatom obtains formal positive charge. The p orbital of the atom directly connected to the heteroatom can be empty, or a part for the multiple bond formed with another atom except the heteroatom. Heteroatom can be the substituent of the atom with pi bond or can be in heterocycle. Exemplary donor groups include, but are not limited to, R2N-- and R n X 1 --, wherein R is an alkyl, aryl or heteroaryl group, X 1 is O, S, P, Se, or Te, and n is 1 or 2. The total number of heteroatoms and carbons in the donor group may be about 30, and the donor group may be further substituted with alkyl, aryl, or heteroaryl groups.

[0043] Suitable electron donating groups "D" for use in nonlinear optical chromophores according to various embodiments of the present invention include those described in the following published U.S. patent applications: US 2007 / 0260062; US 2007 / 0260063; US 2008 / 0009620; US 2008 / 0139812; US 2009 / 0005561; US 2012 / 0267583A1 (collectively, “Prior Publications”), each of which is incorporated herein by reference in its entirety; and those described in the following U.S. Patent Nos. 6,584,266; 6,393,190; 6,448,416; 6,44,830; 6,514,434; 5,044,725; 4,795,664; 5,247,042; 5,196,509; 4,810,338; 4,936,645; 4,767,169; 5,326,661; 5,187,234; 5,170,461; 5,133,037; 5,106,211; and 5,006,285; each of which is also incorporated herein by reference in its entirety.

[0044] In a plurality of preferred embodiments, the electron donating group can include quinolyl groups which can be substituted or unsubstituted, including hydrogen and alkyl substituents, aryl substituents and combinations thereof. According to a plurality of embodiments of the present invention, these quinolyl groups can have one or more covalently attached adamantane groups. In a plurality of preferred embodiments, the electron donating group can include quinolone substituted with alkoxyphenyl, for example:

[0045]

[0046] or

[0047] For example, aromatic nitrogen-containing groups such as:

[0048]

[0049] A "π-bridge" comprises atoms or groups of atoms through which electrons can be delocalized from an electron donor (as defined above) to an electron acceptor (as defined above) via an atomic orbital in the bridge. Such groups are well known in the art. Typically, the orbitals will be di(sp 2) bond or triple (sp) bond carbon atom p orbital, such as those present in olefins, alkynes, neutral or charged aromatic ring systems and neutral or charged heteroaromatic ring systems. In addition, orbital can be a p orbital on an atom such as boron or nitrogen. In addition, orbital can be a p, d or f organometallic orbital or a hybrid organometallic orbital. The bridge atom containing such an orbital is referred to as a "critical atom" in this article, wherein electrons are delocalized by the orbital. The number of critical atoms in the bridge can be a number from 1 to about 30. Critical atoms can be substituted by an organic group or an inorganic group. Substituents can be selected to improve the solubility of the chromophore in the polymer matrix, to improve the stability of the chromophore or for other purposes.

[0050] Suitable bridging groups (Π) for the nonlinear optical chromophores of formula (I) according to the present invention include those described in the following U.S. Patent Nos.: 6,584,266; 6,393,190; 6,448,416; 6,44,830; 6,514,434; each of which is also incorporated herein by reference in its entirety.

[0051] In various preferred embodiments, the bridging group (II) for the nonlinear optical chromophore of formula (I) according to the present invention comprises a chromophore of formula (II a )

[0052]

[0053] wherein X represents a substituted or unsubstituted, branched or unbranched C2-C4 diradical moiety; wherein a and b each independently represent an integer from 0 to 3; and z represents an integer from 1 to 3. In various embodiments, wherein the general formula (II a ) wherein a or b is 1, and the carbon-carbon double bond in the formula may be substituted by a carbon-carbon triple bond. Alternatively, in a number of preferred embodiments, the bridging group (II) for the nonlinear optical chromophore of the general formula (I) according to the present invention comprises a b )

[0054]

[0055] wherein X represents a substituted or unsubstituted, branched or unbranched C2-C4 diyl moiety. In various embodiments of the present invention, wherein one or more adamantane groups are covalently attached to a compound according to formula II a or II b The one or more adamantane groups may be bonded to the sulfur or oxygen atom of the thiophene group or to one or more carbon atoms in X, for example, via an ether or thioether bond.

[0056] In various preferred embodiments, the bridging group (II) for the nonlinear optical chromophore of formula (I) according to the present invention comprises a chromophore of formula (II c )

[0057]

[0058] wherein each Y independently represents: an adamantane-containing group covalently bonded to a bridging group by any of a plurality of bonds described below, including but not limited to ether and thioether bonds; or each Y may represent a hydrogen, an alkyl group, an aryl group, a sulfur- or oxygen-linked alkyl or aryl group, or a branched or unbranched, optionally heteroatom-containing C1-C4 substituent; wherein a and b each independently represent an integer from 0 to 3; z represents an integer from 1 to 3; and wherein each arc A independently represents a substituted or unsubstituted C2-C4 alkyl group that, together with the carbon-bearing Y substituent and its two adjacent carbon atoms, forms a cyclic group. The substituted or unsubstituted C2-C4 alkyl group comprising arc A may include 1 to 4 hydrogen substituents, each of which comprises a moiety selected from the group consisting of: a substituted or unsubstituted C1-C4 10 Alkyl, substituted or unsubstituted C2-C 10 Alkenyl, substituted or unsubstituted C2-C 10 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted alkylaryl, substituted or unsubstituted carbocycle, substituted or unsubstituted heterocycle, substituted or unsubstituted cyclohexyl and (CH2) n -O-(CH2) n , wherein n is 1-10. In various preferred embodiments, z represents 1. In various embodiments according to the present invention, the electron-donating group or the electron-accepting group may include one or more covalently bound adamantane groups, and the general formula II c In certain preferred embodiments, the chromophore may include an electron-donating group comprising one or more covalently linked adamantyl groups, preferably adamantyl groups, and the bridging group may include a c wherein Y represents an aryl thioether substituent.

[0059] In various preferred embodiments, the bridging group (II) for the nonlinear optical chromophore of formula (I) according to the present invention comprises a chromophore of formula (II d )

[0060]

[0061] wherein each Y independently represents: an adamantyl-containing group covalently bonded to a bridging group via any of a plurality of bonds described below, including but not limited to ether and thioether bonds; or each Y may represent hydrogen, an alkyl group, an aryl group, an alkyl or aryl group linked to a sulfur or oxygen, an aryl group directly linked via a carbon-carbon bond (optionally carrying an adamantyl group) (e.g., adamantyl anisole), a halogen, a halogenated alkyl group, a halogenated aryl group, or a branched or unbranched group, optionally containing a heteroatom C1-C4 substituent; wherein a and b each independently represent an integer from 0 to 3; and z represents an integer from 1 to 3. In various embodiments according to the present invention, the electron donating group or the electron accepting group may include one or more covalently bonded adamantyl groups, and the general formula II d In certain preferred embodiments, the chromophore may include an electron-donating group comprising one or more covalently linked adamantyl groups, preferably adamantyl groups, and the bridging group may include a d In various embodiments, the formula II d Each of the paired methyl groups on the isophorone bridge may additionally independently represent a moiety selected from the group consisting of: substituted or unsubstituted C1-C 10 Alkyl, substituted or unsubstituted C2-C 10 Alkenyl, substituted or unsubstituted C2-C 10 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted alkylaryl, substituted or unsubstituted carbocycle, substituted or unsubstituted heterocycle, substituted or unsubstituted cyclohexyl, halogen, haloalkyl groups (e.g., -CF3), haloaryl and heteroaryl groups (e.g., pentafluorothiophenol), and (CH2) n -O-(CH2) n , where n is 1-10.

[0062] For example, the bridging group (II) for the nonlinear optical chromophore of general formula (I) according to the present invention may include:

[0063]

[0064] The nonlinear optical chromophores according to various embodiments of the present invention further comprise one or more adamantanes covalently linked to the chromophore. The one or more adamantanes may be linked to electron-donating groups, electron-accepting groups, and / or π-bridges and may be covalently bonded to multiple chromophores at the 1-position or 2-position of the adamantane. The one or more adamantanes typically extend outward from the chromophore and create steric hindrance (i.e., "space") between two or more of the chromophore molecules in the chromophore-containing material and are therefore used to prevent aggregation during and after polarization.

[0065] Adamantanes suitable for use in various embodiments of the present invention include adamantane (C 10 H 16 ), ice alkane (C 12 H 18 ), diamantane (C 14 H 20 ), triamantane (C 18 H 24 ), isotetramantane (C 22 H 28 ), Pentamantane (C 26 H 32 and C 25 H 30 ), cyclohexamantane (C 26 H 30 ), super adamantane (C 30 H 36 Suitable adamantane can be prepared synthetically, commercially available, or obtained from petroleum-derived refineries. For example, suitable adamantane reagents for adding adamantane groups to various chromophores, such as adamantylthiol and adamantol, are commercially available from suppliers such as Sigma-Aldrich. Synthetic routes to various adamantane groups are also available in the literature. For example, adamantane synthesis is described in Gund, T. et al., "Diamantane. I. Preparation of diamantane. Physical and spectral properties," J. ORG. CHEM. 39(20): 2979-2987, October 1, 1974, the entire contents of which are incorporated herein by reference.

[0066] In preferred embodiments of the nonlinear optical chromophores according to the present invention, the adamantane-like substituents include adamantyl and diadamantyl groups, which can be covalently bonded to the chromophores at positions 1 or 2, as shown in the following formula:

[0067]

[0068] Thus, the nonlinear optical chromophores according to the present invention can include one or more such adamantyl and / or diadamantyl groups covalently attached to the chromophore. According to various embodiments of the present invention, the adamantyl group can be covalently attached to the chromophore, for example, via an ether bond, a thioether bond, a carbon-carbon bond to an aromatic moiety bearing one or more adamantane groups, and the like. For example, the adamantyl group can be added via a nucleophilic substitution reaction of an adamantyl alcohol or thiol with an epoxy group.

[0069] The present invention also includes nonlinear optical materials comprising nonlinear optical chromophores according to embodiments of the present invention (incorporated into a matrix material), as well as blends of two or more chromophores, and pure films of individual chromophores (especially when the chromophore is amorphous). Suitable matrix materials can include polymers such as: poly(methyl methacrylate) (PMMA); polyimide; polyamic acid; polystyrene; poly(urethane) (PU); and amorphous polycarbonate (APC). In various embodiments, the matrix material can include poly(methyl methacrylate), such as poly(methyl methacrylate) having a molecular weight of about 120,000 and a glass transition temperature, Tg, of about 85-165°C, or APC having a Tg of about 150-220°C.

[0070] The nonlinear optical chromophores according to embodiments of the present invention are typically incorporated into the matrix material at a loading of 1 wt% to 50 wt%, more preferably 2 wt% to 35 wt%, and most preferably 3 wt% to 35 wt%, based on the total nonlinear optical material. The nonlinear optical materials according to various embodiments of the present invention may be in the form of a solid thin film, optionally disposed on the surface of another material. In general, the nonlinear optical materials according to the present invention include all currently known forms of such materials, but the optical chromophores incorporated into the matrix material include nonlinear optical chromophores according to embodiments of the present invention described herein.

[0071] The present invention also relates to electro-optical devices comprising nonlinear optical materials according to various embodiments of the present invention. Electro-optical device and / or system embodiments of the present invention include phased array radar, satellite and fiber optic communications, cable television (CATV), optical gyroscopes for air and missile guidance, electronic countermeasures (ECM) systems, backplane interconnects for high-speed computing, ultrafast analog-to-digital conversion, mine detection, radio frequency optoelectronics, spatial light modulation, and all-optical (optically switched light) signal processing, wherein such devices include nonlinear optical materials according to the present invention. In addition, the extremely broad absorption spectrum of the nonlinear optical chromophores according to the present invention, which essentially covers the entire UV-Vis-NIR region from 250 nm to 1800 nm at high extinction coefficients, indicates that the nonlinear optical materials according to various embodiments of the present invention may also be used in solar energy conversion and photovoltaic devices.

[0072] A preferred embodiment of an electro-optical device according to the present invention comprises an electro-optical modulator for telecommunications, wherein the modulator comprises a nonlinear optical material according to the present invention. Another preferred device is an all-optical device. Such a device can be used for optical switching of third-order hyperpolarizability, parametric amplification, and other all-optical applications.

[0073] Various preferred chromophores according to embodiments of the present invention include:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] The present invention will now be described in more detail with reference to the following non-limiting examples.

[0085] Example

[0086] Synthesis Example 1:This article describes in detail the preparation of 2-[4-[(E,3E)-3-[2-(1-adamantylsulfanyl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene]prop-1-enyl]-3-cyano-5-phenyl-5-(trifluoromethyl)-2-furylidene]malononitrile.

[0087] Example 1a .Synthesis of 1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline.

[0088]

[0089] A solution of 2,2,4,7-tetramethyl-3,4-dihydro-1H-quinoline (10.0 g, 0.0528 mol) and 1-bromo-4-methoxy-benzene (83.0%, 11.9 g, 0.0528 mol) in toluene (35.0 mL) was bubbled with N2 and then treated with potassium tert-butoxide (7.71 g, 0.0687 mol), Pd(OAc)2 (0.593 g, 0.00264 mol), and tri-tert-butylphosphine (1.07 g, 0.00528 mol). The flask was equipped with a condenser and a nitrogen inlet. The reaction mixture was heated to 111°C for 64 hours.

[0090] The reaction mixture was diluted with MeOH and then concentrated. The residue was dissolved in dichloromethane ("DCM") and the solids were removed by vacuum filtration. The filtrate was washed with water and brine, and the organic matter was dried over MgSO4, filtered, and concentrated. The crude material was purified by normal phase ("NP") chromatography (0-50% EtOAc in hexanes). The product fractions were concentrated to give 1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline (94.0%, 14.5 g, 0.0461 mol, yield: 87.3%) as an amber concentrate.

[0091] Example 1b .Synthesis of 1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-carbaldehyde.

[0092]

[0093] A solution of 1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline (94.0%, 10.9 g, 0.0346 mol) in DMF (30.0 mL) was bubbled with N2 and cooled in an ice bath. POCl3 (7.92 mL, 0.0865 mol) was slowly added via a syringe. The mixture was stirred on ice for 2 hours, at which point LCMS analysis showed complete conversion to Vilsmeier adduct (m / z 351) and aldehyde. The reaction was quenched by adding water and diluted with DCM and stirred at room temperature for 16 hours.

[0094] The reaction mixture was extracted with DCM, and the combined organics were washed with water, dried over phase separation paper, and concentrated. The crude material was purified by NP chromatography (0-50% EtOAc in hexanes). The product fractions were concentrated to give 1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-carbaldehyde (10.6 g, 0.0326 mol, yield: 94.3%) as a light yellow powder.

[0095] Example 1c .Synthesis of 2-(1-adamantylsulfhydryl)-3,5,5-trimethyl-cyclohex-2-en-1-one.

[0096]

[0097] A solution of sodium ethoxide (21.0%, 23.6 mL, 0.0632 mol) in ethanol (200 mL) was sparged with N2 and then treated with adamantane-1-thiol (95.0%, 44.8 g, 0.253 mol). The mixture was stirred at room temperature under N2 for 10 minutes, followed by the addition of 4,4,6-trimethyl-7-oxabicyclo[4.1.0]heptan-2-one (39.0 g, 0.253 mol). The flask was capped and the mixture continued to stir at room temperature. After 10 minutes, the reaction mixture was quenched with water, and the solid precipitate was isolated and dried by vacuum filtration to afford 2-(1-adamantylsulfhydryl)-3,5,5-trimethyl-cyclohex-2-en-1-one (73.9 g, 0.243 mol, 95.9% yield) as an off-white solid.

[0098] Example 1d .Synthesis of 2-(1-adamantylsulfhydryl)-3-[(E)-2-[1-(4-methoxyphenyl)-3,4-dihydro-2H-quinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-en-1-one.

[0099]

[0100] To a 100 mL round-bottom flask was added ethanol (8.00 mL) and sparged with N2. Added to this was 1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-carbaldehyde (5.00 g, 0.0155 mol), 2-(1-adamantylthiohydrido)-3,5,5-trimethyl-cyclohex-2-en-1-one (4.94 g, 0.0162 mol), lithium ethoxide (95.0%, 0.212 g, 0.00386 mol), and piperidine (1.53 mL, 0.0155 mol). The flask was sealed with a septum and lined with N2. The mixture was stirred at 70°C for 64 hours.

[0101] The reaction mixture was diluted with MeOH and cooled in a -20°C freezer, and an orange solid was isolated by vacuum filtration. The material was recrystallized from 10:1 MeOH / H2O, and the resulting solid was isolated and dried by vacuum filtration to afford 2-(1-adamantylthiohydrido)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-en-1-one (99.0%, 7.09 g, 0.0115 mol, yield: 74.4%) as a bright orange powder.

[0102] Example 1e .Synthesis of (2E)-2-[2-(1-adamantylsulfanyl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene]acetonitrile.

[0103]

[0104] The 500mL round-bottom flask was dried with a heat gun and then bubbled with N2. A 99mL THF solution of acetonitrile (3.36mL, 0.0644mol) was then added, and the mixture was cooled to -78°C. n-BuLi (2.50M, 25.4mL, 0.0636mol) was then added dropwise over a period of approximately 10 minutes, and the mixture was stirred under N2 at the same temperature for 10 minutes (the mixture became an opaque, turbid white color). The flask was then placed in a refrigerator at 2-8°C for 30 minutes. The sealed flask is then placed back in a dry ice / acetone bath, an N2 catheter is inserted, and a solution of 2-(1-adamantylsulfhydryl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-yl] vinyl]-5,5-dimethyl-cyclohex-2-ene-1-one (97.0%, 5.00g, 0.00795mol-dried under high vacuum) in another 54mL THF is added dropwise (bubbled with N2 and ultrasonically treated to ensure that all solids dissolve) by a syringe through a septum. After 3 hours, the reaction is quenched by adding water and warmed to room temperature, then extracted into EtOAc. The combined organics are dried over anhydrous MgSO4, filtered, and concentrated. The foamy orange residue is dissolved in 20mL AcOH, the flask is then sealed with a septum, and the mixture is stirred at 70°C for 16 hours.

[0105] The reaction mixture was diluted with DCM and washed with a saturated aqueous bicarbonate solution. The aqueous phase was extracted with additional DCM, and the combined organics were then washed with another saturated aqueous bicarbonate solution. The combined organics were dried over phase separation paper and concentrated. The material was eluted with DCM through a silica gel plug. The filtrate was concentrated to give (2E)-2-[2-(1-adamantylsulfhydryl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene]acetonitrile (95.5%, 4.78 g, 0.00721 mol, yield: 90.7%) as a foamy red solid.

[0106] Example 1f .Synthesis of (2E)-2-[2-(1-adamantylsulfanyl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene]acetaldehyde.

[0107]

[0108] A solution of (2E)-2-[2-(1-adamantylsulfanyl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-en-1-ylidene]acetonitrile (93.0%, 17.3 g, 0.0255 mol) in 55 mL of DCM was bubbled with N, cooled in an ice bath, and treated dropwise with diisobutylaluminum hydride ("DIBAL") (1.00 M, 38.2 mL, 0.0382 mol). The mixture was stirred at room temperature for 15 minutes.

[0109] The reaction mixture was quenched by adding sodium sulfate decahydrate until gas evolution stopped. The mixture was then adsorbed onto silica gel and purified by NP chromatography (100% DCM). The concentrated product fractions gave (2E)-2-[2-(1-adamantyl sulfhydryl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl] vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene] acetaldehyde (10.4 g, 0.0164 mol, yield: 79.8%), which was a dark red-black solid.

[0110] Example 1g .Synthesis of 2-[4-[(E,3E)-3-[2-(1-adamantylsulfanyl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-en-1-ylidene]prop-1-enyl]-3-cyano-5-phenyl-5-(trifluoromethyl)-2-furylidene]malononitrile.

[0111]

[0112] A round-bottom flask containing (2E)-2-[2-(1-adamantylthiohydrido)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-en-1-ylidene]acetaldehyde (96.0%, 9.52 g, 0.0144 mol) and 2-[3-cyano-4-methyl-5-phenyl-5-(trifluoromethyl)-2-furylidene]malononitrile (4.99 g, 0.0158 mol) was diluted with 1-propanol (50.0 mL). The mixture was sparged with N2 and the flask was covered with foil to block all light. The flask was sealed with a septum and an N2 line was inserted, and the mixture was stirred at 66°C for 45 minutes. The mixture was cooled to room temperature, and the solid was isolated by filtration. The solid was purified by NP chromatography (prepared by eluting 25 mL of DCM with 0.5 mL of ethylamine and then adding the product). The product fractions were concentrated and the residue was recrystallized from DCM / MeOH. The solid was then ground with ether and dried to give 2-[4-[(E, 3E)-3-[2-(1-adamantyl hydrosulfenyl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl] vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene] prop-1-enyl]-3-cyano-5-phenyl-5-(trifluoromethyl)-2-furylidene] malononitrile (6.93 g, 0.00743 mol, yield: 51.7%) as a copper red powder.

[0113] Liquid chromatography / mass spectrometry (LCMS) analysis of the liquid indicated almost complete conversion to the desired product. The mixture was cooled to room temperature and then in a -20°C freezer for 20 minutes. The solid was collected.

[0114] The solid was dissolved in dichloromethane and filtered through a pad of silica gel, eluting with dichloromethane.Fraction 2, 3, 4 and 5 were concentrated and analyzed separately.

[0115] The purity of all four fractions was between 90% and 96%, so they were combined and recrystallized from a dichloromethane / methanol mixture by slow evaporation of dichloromethane. LCMS analysis of the solid obtained from the recrystallization showed a purity of approximately 94%. The solid was then soaked in ether, filtered and dried under high vacuum to give 2-[4-[(E,3E)-3-[2-(1-adamantylsulfhydryl)-3-[(E)-2-[1-(4-methoxyphenyl)-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-cyclohex-2-ene-1-ylidene]prop-1-enyl]-3-cyano-5-phenyl-5-(trifluoromethyl)-2-furylidene]malononitrile (0.0400 g, 4.29e-5 mol, yield: 6.98%).

[0116] LCMS analysis: 99.6% purity. m / z 932.46, M+H

[0117] 1 H NMR (500MHz, solvent) δppm 8.22 (dd, J=40.09, 11.46Hz, 1H) 7.71-8.10 (m, 1H) 7.61-7.70 (m, 2H) 7.51 (br s, 5H) 7.24 (br dd, J=16.04, 8.02Hz, 1H) 7.02 (br d,J=7.45Hz,2H)6.92-6.99(m,2H)6.50(dd,J=34.94,16.04Hz,1H)5.72(s,1H)3.83(s,3H)3.09(br dd,J=12.03,5.73Hz,1H)2.62-2.75(m,1H)2.49(br dd,J=17.47,4.87Hz,1H)2.32-2.42(m,2H)2.12(s,3H)1.96(br s,3H)1.89(dd,J=13.75,6.30Hz,1H)1.84(br s,6H)1.61(br d,J=14.32Hz,7H)1.43(d,J=6.30Hz,3H)1.28(s,3H)1.03(br s,3H)1.00(br d,J=5.15Hz,3H)0.83-0.97(m,3H).

[0118] Temporal stability of the product of Synthesis Example 1: The chromophore of Synthesis Example 1 has a glass transition temperature of about 152°C. A film with a thickness of 1-2 μm was prepared by dissolving the chromophore of Synthesis Example 1 (35 wt %) in 1,1,2 trichloroethane (10% solids) and spin coating an ITO-coated glass substrate at 2000 rpm. The solvent was removed in vacuo at 80°C for 16 hours. A gold pad (50 nm) was sputtered on the film to produce a top electrode. These simple devices were then polarized at 155°C and 100 V / μm nitrogen for 60 seconds and cooled in the field to maintain the polarization state. Preliminary measurements of the electro-optic coefficient (r33) were made and the samples were stored in an oven at 85°C and re-measured periodically. The results are listed in Table 1 below and are given in Table 1. Figure 1 From Table 1 and Figure 1 As can be seen from the data in , the electro-optical properties of the thin films prepared using the chromophores according to embodiments of the present invention exhibit remarkable long-term thermal stability.

[0119] Table 1 Synthesis Example 1 film time stability (remaining after storage at 85 ℃ r 33 )

[0120] Time (hours) <![CDATA[Remaining r 33 (%)]]> 0 100 64 91.4 398 90.8 704 89.8

[0121] Synthesis Example 2 :This article describes in detail the preparation of 2-[4-[(E,3E)-3-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-ene-1-ylidene]prop-1-enyl]-3-cyano-5-(4-phenylphenyl)-5-(trifluoromethyl)-2-furylidene]malononitrile.

[0122] Example 2a .Synthesis of 1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinoline.

[0123]

[0124] A solution of 2,2,4,7-tetramethyl-3,4-dihydro-1H-quinoline (24.5 g, 0.129 mol) and 1-(5-bromo-2-methoxyphenyl)adamantane (97.0%, 50.0 g, 0.151 mol) in 70 mL of toluene was sparged with N2 and then treated with sodium tert-butoxide (16.2 g, 0.168 mol), Pd(OAc)2 (1.45 g, 0.00647 mol), and tri-tert-butylphosphine (2.62 g, 0.0129 mol). The flask was equipped with a condenser and a nitrogen inlet. The reaction mixture was heated to 111°C for 60 hours.

[0125] The reaction mixture was diluted with DCM and the solids were removed by vacuum filtration. The filtrate was purified by NP chromatography (50% DCM in hexane - isocratic eluent). The product fractions were concentrated to obtain a highly impure product. The solid was dissolved in 500 mL of DCM and allowed to stand at room temperature for 16 hours. The volume of DCM was reduced to approximately 200 mL, and then methanol was added. The mixture was stirred until solids began to form. A brown solid precipitated from the mixture. These solids were separated and dried by vacuum filtration to obtain a product with a purity of 87%. The solid was then soaked in methanol at room temperature for 1 hour, then re-isolated and dried to obtain 1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinoline (92.0%, 39.8 g, 0.0852 mol, yield: 65.8%) as a yellow-brown solid.

[0126] Example 2b .Synthesis of 1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-carbaldehyde.

[0127]

[0128] A solution of N,N-dimethylformamide (18.0 mL, 0.232 mol) in dichloromethane (50 mL) was bubbled with N2 and cooled on ice. POCl3 (9.35 mL, 0.102 mol) was then added, and the mixture was stirred at the same temperature for about 30 minutes until the solution turned light pink. A solution of 1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinoline (92.0%, 21.7 g, 0.0464 mol) in another 50 mL of DCM was then slowly added. The mixture was stirred for 20 minutes, then quenched by slowly adding 10% aqueous Na2CO3 and stirred vigorously for 16 hours.

[0129] The aqueous and organic layers were separated, and the aqueous layer was extracted with additional DCM. The combined organics were dried over phase separation paper and purified by NP chromatography (0-50% ethyl acetate in hexanes). The product fractions were concentrated to afford 1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-carbaldehyde (97.5%, 15.3 g, 0.0326 mol, yield: 70.2%) as a pale yellow solid.

[0130] Example 2c .Synthesis of 3,5,5-trimethyl-2-phenylsulfhydryl-cyclohex-2-en-1-one.

[0131]

[0132] A solution of thiophenol (10.1 mL, 0.106 mol) in ethanol (75.0 mL) was treated with sodium ethoxide (21.0%, 7.50 mL, 0.0201 mol). The mixture was stirred at room temperature for 20 minutes, then 4,4,6-trimethyl-7-oxabicyclo[4.1.0]heptan-2-one (15.5 g, 0.101 mol) was added dropwise over approximately 20 minutes. Halfway through the addition, the reaction flask was placed on ice in an attempt to reduce the exotherm. LCMS analysis immediately after the complete addition of isophorone indicated complete conversion to the desired product.

[0133] The reaction mixture was diluted with DCM and concentrated. The residue was then purified by NP chromatography (0-50% ethyl acetate in hexanes). The appropriate fractions were concentrated to yield 3,5,5-trimethyl-2-phenylthio-cyclohex-2-ene-1-one (92.6%, 24.5 g, 0.0923 mol, yield: 91.8%) as a yellow concentrate that rapidly solidified upon cooling.

[0134] Example 2d .Synthesis of 3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfhydryl-cyclohex-2-en-1-one.

[0135]

[0136] A solution of 1-[3-(1-adamantyl)-4-methoxyphenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinoline-6-carbaldehyde (97.5%, 15.3 g, 0.0326 mol) in ethanol (25.0 mL) was sparged with N2. To this was added 3,5,5-trimethyl-2-phenylthiohydridocyclohex-2-en-1-one (10.4 g, 0.0423 mol), lithium ethoxide (95.0%, 0.446 g, 0.00815 mol), and piperidine (3.22 mL, 0.0326 mol). The flask was sealed with a septum, and the mixture was stirred at 70°C for 60 hours.

[0137] The mixture was cooled to room temperature, then diluted with 50% MeOH / H₂O and cooled in a refrigerator at 2-8°C. Some red solid was isolated by vacuum filtration. The material was recrystallized from 50% MeOH / H₂O, and the resulting solid was isolated and dried by vacuum filtration. The solid was then adsorbed onto silica gel and purified by NP chromatography (100% DCM). The appropriate fractions were concentrated to yield 3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfhydryl-cyclohex-2-en-1-one (81.0%, 23.9 g, 0.0282 mol, yield: 86.6%) as bright reddish-orange flakes.

[0138] Example 2e .Synthesis of (2E)-2-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-ene-1-ylidene]acetonitrile.

[0139]

[0140] A solution of sodium hydride (60.0%, 4.06 g, 0.102 mol) in THF (100 mL) was bubbled with N₂ at room temperature. Diethyl cyanomethylphosphonate (98.0%, 16.8 mL, 0.102 mol) was then added dropwise (with significant gas evolution), and the mixture was stirred at room temperature under N₂ until it became clear (approximately 20 minutes). A solution of 3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-en-1-one (81.0%, 21.5 g, 0.0254 mol) in another 50 mL of THF was added, and the flask was equipped with a condenser. The mixture was stirred at reflux for 16 hours.

[0141] The reaction mixture is concentrated and the residue is then purified by NP chromatography (50-100% DCM in hexane). Appropriate fractions are concentrated to obtain a product with a purity of only 77%. The material is dissolved in a minimum volume of DCM. MeOH is added thereto. A slow N2 stream is applied to the solution to promote the evaporation of DCM. Initially, the product appears to separate out from the solution as a dark viscous substance. Then, as more DCM evaporates, a bright orange solid precipitates out. After about 15-20 minutes, the solid was separated and dried by vacuum filtration to give (2E)-2-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-ene-1-ylidene]acetonitrile (93.0%, 15.8 g, 0.0207 mol, yield: 81.6%) as a bright orange solid.

[0142] Example 2f .Synthesis of (2E)-2-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-ene-1-ylidene]acetaldehyde.

[0143]

[0144] A solution of (2E)-2-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-ene-1-ylidene]acetonitrile (93.0%, 15.8 g, 0.0207 mol) in 50.0 mL of DCM was sparged with N and treated dropwise with DIBAL (1.00 M, 22.8 mL, 0.0228 mol). The mixture was stirred at room temperature - after 15 minutes, LCMS indicated that only about 26% of the starting material had been converted to the imine and aldehyde. An additional 15 mL of DIBAL was added, and the mixture was stirred for 16 hours.

[0145] The reaction mixture was then quenched by adding sodium sulfate decahydrate until gas evolution ceased. The mixture was then adsorbed onto silica gel and purified by NP chromatography (75%-100% DCM in hexane). The product fractions were concentrated, and LCMS analysis showed complete hydrolysis to an aldehyde with a purity of approximately 95%. The solid was then recrystallized from DCM / MeOH to give (2E)-2-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl] vinyl]-5,5-dimethyl-2-phenylsulfhydryl-cyclohexyl-2-ene-1-ylidene] acetaldehyde (95.0%, 12.7 g, 0.0169 mol, yield: 81.5%) as a dark red solid.

[0146] Example 2f .Synthesis of 2-[4-[(E,3E)-3-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-ene-1-ylidene]prop-1-enyl]-3-cyano-5-(4-phenylphenyl)-5-(trifluoromethyl)-2-furylidene]malononitrile.

[0147]

[0148] A round-bottom flask containing (2E)-2-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-en-1-ylidene]acetaldehyde (95.0%, 12.7 g, 0.0169 mol) and 2-[3-cyano-4-methyl-5-(4-phenylphenyl)-5-(trifluoromethyl)-2-furylidene]malononitrile (7.27 g, 0.0186 mol) was diluted with 1-propanol (40.0 mL). The mixture was sparged with N2 and the flask was covered with foil to block all light. The flask was sealed with a septum, an N2 line was inserted, and the mixture was stirred at 65°C for 24 hours. An additional 0.1 eq of receptor was added to the mixture, which was then cooled to room temperature and stirred at that temperature for 60 hours. The heat was then increased to 70°C, an additional 0.1 eq of receptor was added, and the mixture was stirred for 1.5 hours. The mixture was cooled to room temperature and then further cooled in a refrigerator at 2-8°C.

[0149] Then separate the solid by filtration. Collect the solid and dissolve it in DCM. About half of the material is used to test the purification conditions. Prepare three ground glass sinter funnels with slurries of different chromatographic media: neutral Al2O3, alkaline Al2O3 and SiO2 (prepared with about 1mL NEt3). Set aside about 1 / 3DCM solution for testing and elute through each of the three media. After complete elution, carry out TLC and LCMS analysis. It seems that SiO2 performs well in removing baseline material. Merge the eluted material and concentrate. The material is dissolved in a minimum of DCM (to prepare a thick concentrate), then MeOH is added. The mixture is cooled in a refrigerator for 1 hour, then the solid is collected by vacuum filtration. This procedure is carried out five more times until the part reaches a purity of> 99%. The remaining half of the original material is divided into two parts again, and the same purification procedure is carried out.

[0150] The solids from all batches were combined and collected by vacuum filtration to give 2-[4-[(E,3E)-3-[3-[(E)-2-[1-[3-(1-adamantyl)-4-methoxy-phenyl]-2,2,4,7-tetramethyl-3,4-dihydroquinolin-6-yl]vinyl]-5,5-dimethyl-2-phenylsulfanyl-cyclohex-2-en-1-ylidene]prop-1-enyl]-3-cyano-5-(4-phenylphenyl)-5-(trifluoromethyl)-2-furylidene]malononitrile (7.68 g, 0.00708 mol, yield: 41.9%) as a black powder.

[0151] 1H NMR (500MHz, acetone-d6) δppm 7.98-8.12(m,1H)7.84-7.93(m,3H)7.79(d,J=8.59Hz,2H)7.71(d,J=7.45Hz,2H)7.54(d,J=12.03Hz,1H)7.38 -7.51(m,4H)7.20-7.25(m,2H)7.15-7.19(m,2H)7.06-7.11(m,1H)7.02-7.06(m,1H)6.87-6.98(m,2H)6.69(br d,J=14.32Hz,1H)5.67(s,1H)3.89(d,J=2.86Hz,3H)2.92-3.06(m,1H)2.79(br s,4H)2.75(s,2H)2.48-2.60(m,1H)2.38-2.47(m,1H)2.03-2.12(m,9H)1.91(dd,J=13.17,5.15Hz,1H)1.74(br d, J=8.02Hz, 6H) 1.63 (q, J=13.17Hz, 1H) 1.17-1.34 (m, 6H) 0.96-1.15 (m, 6H) 0.88-0.94 (m, 3H).

[0152] Temporal stability of the product of Synthesis Example 2 : The chromophore of Synthesis Example 2 has a glass transition temperature of about 176°C. A film with a thickness of 1-2 μm was prepared by dissolving the chromophore of Synthesis Example 2 (35 wt %) in 1,1,2 trichloroethane (10% solids) and spin coating an ITO-coated glass substrate at 2000 rpm. The solvent was removed in vacuo at 80°C for 16 hours. A gold pad (50 nm) was sputtered on the film to produce a top electrode. These simple devices were then polarized at 155°C and 100 V / μm nitrogen for 60 seconds and cooled in the field to maintain the polarization state. Preliminary measurements of the electro-optic coefficient (r33) were made and the samples were stored in an oven at 85°C and re-measured periodically. The results are listed in Table 2 below and are given in Table 2. Figure 2 From Table 2 and Figure 2 As can be seen from the data in , the electro-optical properties of the thin films prepared using the chromophores according to embodiments of the present invention exhibit remarkable long-term thermal stability.

[0153] Table 2 Synthesis Example 2 film time stability (remaining after storage at 85 ℃ r 33 )

[0154] Time (hours) <![CDATA[Remaining r 33 (%)]]> 0 100 64 99.6 256 88.9 448 87.9 784 89.7

[0155] It will be appreciated by those skilled in the art that changes may be made to the embodiments described above without departing from the broad inventive concept. It should therefore be understood that the present invention is not limited to the particular embodiments disclosed, but is intended to encompass modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A nonlinear optical chromophore having the general formula (I): D-Π-A(I) wherein D represents an organic electron-donating group; A represents an organic electron-accepting group having an electron affinity greater than that of D; and π represents a π-bridge between the organic electron-accepting group and the organic electron-donating group; wherein D comprises a quinolinyl group selected from: wherein the π-bridge has the following formula (II d ): wherein Y is independently selected from: a sulfur-linked unsubstituted alkyl or aryl group; wherein a and b each independently represent 1; and z represents 1; Wherein A represents the general formula (I a ) of the organic electron-accepting group: where R 2 and R 3 One of them represents a halogen-substituted C1-C 10 an alkyl moiety, the other represents an unsubstituted aromatic moiety; or R 2 and R 3 One of them represents a halogen-substituted aromatic moiety, and the other represents an unsubstituted C1-C 10 alkyl moiety; The nonlinear optical chromophore comprises an adamantane, wherein the adamantane is selected from the group consisting of adamantane, iceane, diamantane, triamantane, isotetramantane, pentamantane, cyclohexamantane and superamantane, wherein the adamantane is covalently bonded to one of the organic electron-donating groups and / or the π-bridge.

2. The nonlinear optical chromophore of claim 1 , wherein the adamantane is covalently bound to the π-bridge.

3. The nonlinear optical chromophore of claim 1, wherein the adamantane is covalently bound to the organic electron-donating group.

4. A nonlinear optical chromophore selected from the group consisting of:

5. An electro-optical film comprising the nonlinear optical chromophore according to claim 1, the nonlinear optical chromophore being dispersed and polarized within a host polymer matrix.

6. An electro-optical device comprising the electro-optical film according to claim 5.

7. An electro-optical film comprising the nonlinear optical chromophore according to claim 4, said nonlinear optical chromophore being dispersed and polarized within a host polymer matrix. An electro-optical device comprising the electro-optical film according to claim 7 .

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