C2 symmetric compounds, lanthanide polynuclear complexes, and methods of making and using the same

Abstract

The application discloses a C2 symmetry compound with a metal organic chromophore; a double tridentate ligand with 2,6-pyridine diamide as a chelating site is used for preparation of a transition-lanthanide (d / f) heterometallic supramolecular cage fluorescent thermometer, the fluorescent thermometer has excellent structural designability, stability and sensitivity. The temperature response factor is determined by experiments to be 0.54% / K. The sensitivity is equivalent to that of the currently reported metal organic supramolecular temperature optical sensing materials, and the introduction of the metal organic chromophore in the ligand expands the excitation wavelength to the visible light region, thereby providing a new selection for photochemical supramolecular devices.

Description

Technical Field

[0001] This application relates to a C2 symmetrical compound, a lanthanide polynuclear complex, and their preparation methods and applications, belonging to the field of photochemical supramolecular science. Background Technology

[0002] Temperature, as a fundamental physical parameter, has wide applications in natural science and daily life, making the development of accurate temperature measurement methods of paramount importance. Traditional contact thermometers cannot meet the demands of complex temperature measurement environments, leading to the development of accurate non-contact thermometers that can operate even in strong electromagnetic fields. In recent years, optical temperature sensing materials have attracted widespread attention. Molecular-based optical temperature sensing materials offer advantages such as fast response speed, non-contact temperature detection, and nanometer-level resolution, and are widely used in fields such as biology and medicine.

[0003] Rare earth complexes exhibit excellent luminescence properties due to their unique 4f-4f electronic transitions, emitting wavelengths covering the visible and near-infrared regions with narrow emission bands, making them suitable for display devices and sensing devices. Introducing "antenna molecules" with strong absorption capabilities, broad absorption bands, long triplet excited-state lifetimes, and energy matching with the excited-state energy levels of lanthanide metals can effectively sensitize lanthanide metal luminescence. The emission band of the metal center is unaffected by the intensity of the excitation source, the concentration of luminescent centers, and the sensitivity of the optical detector; therefore, lanthanide metal complexes are currently widely used in optical temperature sensing materials.

[0004] However, current lanthanide optical temperature sensing materials are limited to the ultraviolet light region for excitation, resulting in poor excitation light transmittance and potential harm to organisms in biological applications. Developing visible light-excited optical temperature sensing materials is currently a key research focus. Summary of the Invention

[0005] According to one aspect of this application, a C2 symmetric compound is provided. This C2 symmetric compound, as a transition metal-organic ligand, has an MLCT transition and can sensitize rare earth luminescence. The emission range covers the visible and near-infrared light regions. The presence of the metal-organic group in the ligand causes the excitation spectrum to redshift to the visible light region (400-550 nm). The emission spectrum of the rare earth is temperature sensitive, exhibiting temperature sensing characteristics, and can be used in photochemical temperature sensor devices.

[0006] According to a first aspect of this application, a C2 symmetrical compound is provided, having the structural formula shown in Formula I:

[0007]

[0008] Wherein, R is selected from any one of C1 to C6 alkyl groups and substituted C1 to C6 alkyl groups;

[0009] Selected from any one of the groups having the structural formula shown in Formula II and the groups having the structural formula shown in Formula III;

[0010]

[0011] M is selected from either V-type group VIII metals or linear group VIII metals.

[0012] Optionally, R is selected from C1 to C4 alkyl groups.

[0013] Specifically, the C2 symmetric compounds in this application have a conjugated structure.

[0014] Optionally, Selected from any of the following groups:

[0015]

[0016] Wherein, R1 is selected from H, and any one of C1-C6 alkyl groups; R3 is selected from any one of C1-C6 alkyl groups; R4 is selected from any one of C1-C6 alkylene groups; R5 is selected from any one of C1-C6 alkyl groups, and C6-C6 alkylene groups. 12 R2 is selected from any of the aryl groups; R2 is selected from any of C and N.

[0017] Optionally, M is selected from Pt; the substituents in the substituted C1-C6 alkyl group are selected from C6-C6. 12 Any of the aryl groups.

[0018] Optionally, Selected from any of the following groups:

[0019]

[0020]

[0021] Optionally, R is selected from any of the following groups:

[0022]

[0023] Chiral carbon is marked with *.

[0024] Optionally, R is selected from phenylethyl, naphthylethyl, and isopropyl.

[0025] The C2 symmetric compound provided in this application possesses a metal-organic chromophore; it serves as a doubly tridentate ligand with 2,6-pyridinediamide as the chelating site for the preparation of a transition-lanthanide (d / f) heterometallic supramolecular cage fluorescence thermometer, Ln4L6, wherein Ln is selected from at least one group IIIB and group VIII metal elements. The Ln4L6 fluorescence thermometer exhibits excellent structural designability, stability, and sensitivity. The experimentally measured temperature response factor is -0.54% / K. This sensitivity is comparable to currently reported metal-organic supramolecular temperature optical sensing materials, and the introduction of the metal-organic chromophore in the ligand extends the excitation wavelength to the visible light region, providing a new option for photochemical supramolecular devices.

[0026] According to a second aspect of this application, a method for preparing the above-mentioned C2 symmetric compound is provided, the method comprising:

[0027] The C2 symmetrical compound can be obtained by subjecting a mixture containing halogen compound i and alkynyl compound ii to a substitution reaction.

[0028] The halogen compound i is selected from any one of compounds having the structural formula shown in Formula IV and compounds having the structural formula shown in Formula V;

[0029]

[0030] The alkynyl compound ii is selected from any one of the compounds having the structural formula shown in Formula VI;

[0031]

[0032] Wherein, X is selected from halogens; M is selected from any of the V-type group VIII metal elements or the linear group VIII metal elements.

[0033] Optionally, the substitution reaction is a nucleophilic substitution reaction.

[0034] Optionally, the conditions for the substitution reaction are: temperature of 20–40°C; time of xx–xx.

[0035] Preferably, the temperature of the substitution reaction is 30°C.

[0036] Optionally, the molar ratio of the halogen compound i to the alkynyl compound ii is 1:2 to 4.

[0037] Optionally, the molar ratio of the halogen compound i to the alkynyl compound ii is 1:2.5.

[0038] Optionally, the mixture may also include a catalyst and an acid-binding agent.

[0039] Preferably, the catalyst is selected from at least one of cuprous iodide and cuprous chloride;

[0040] The acid-binding agent is selected from at least one of triethylamine, diethylamine, pyridine, N,N-diisopropylethylamine, triethanolamine, and tetrabutylammonium bromide.

[0041] Optionally, the molar ratio of the catalyst to the halogen compound i is 1:0.05 to 0.2;

[0042] The molar ratio of the acid-binding agent to the halogen compound i is 1:200-400.

[0043] Optionally, the molar ratio of the catalyst to the halogen compound i is 1:0.1;

[0044] The molar ratio of the acid-binding agent to the halogen compound i is 1:287.

[0045] Optionally, the mixture may also include a solvent.

[0046] Optionally, the solvent is selected from at least one of N,N-dimethylformamide, dichloromethane, and tetrahydrofuran.

[0047] Optionally, the substitution reaction is carried out under stirring.

[0048] Optionally, the substitution reaction may further include a separation and purification step.

[0049] As one specific implementation method, the preparation method of the C2 symmetric compound includes:

[0050]

[0051] DCM stands for dichloromethane, and TEA stands for triethylamine.

[0052] According to a third aspect of this application, a lanthanide polynuclear complex is provided, the lanthanide polynuclear complex having the general formula shown in Formula VII:

[0053]

[0054] Wherein, Ln is selected from any of the lanthanide elements, and n is selected from 1 or 2;

[0055] L is an organic ligand selected from the above-mentioned C2 symmetrical compounds and the C2 symmetrical compounds prepared according to the above method;

[0056] In this case, the nitrogen atom in L is coordinated with Ln.

[0057] Optionally, n is 2, and the crystal structure of Ln4L6 belongs to the monoclinic system with space group C2 / c; cell parameters... α=γ=90°, β=98.483(4)°, Z = 8.

[0058] Optionally, the lanthanide polynuclear complex is selected from d / f heterometallic organospirals or d / f heterometallic organotetrahedral cages;

[0059] The nitrogen atom in L is coordinated with Ln at the vertices of the helix or tetrahedron.

[0060] Optionally, the d / f heterometallic organic tetrahedral cage is selected from any of the compounds having the structural formula shown in Formula VIII;

[0061]

[0062] The d / f heterometallic organic spirochete is selected from any of the compounds having the structural formula shown in Formula IX;

[0063]

[0064] in, Let Ln be the value.

[0065] Optionally, Ln is selected from any one of Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0066] According to a fourth aspect of this application, a method for preparing the above-mentioned lanthanide polynuclear complex is provided, the method comprising:

[0067] The lanthanide polynuclear complex can be obtained by reacting materials containing lanthanide precursors and organic ligand L at 40–60 °C.

[0068] Optionally, the lanthanide precursor is selected from Ln trifluoromethanesulfonic acid compounds;

[0069] Preferably, the trifluoromethanesulfonic acid compound of Ln is selected from any one of Pr(OTf)3, Nd(OTf)3, Sm(OTf)3, Eu(OTf)3, Gd(OTf)3, Tb(OTf)3, Dy(OTf)3, Ho(OTf)3, Er(OTf)3, Tm(OTf)3, Yb(OTf)3, and Lu(OTf)3.

[0070] Optionally, the molar ratio of the lanthanide precursor to the organic ligand L is 2:2.5 to 3.5;

[0071] The number of moles of the lanthanide precursor is expressed as the number of moles of the lanthanide element.

[0072] Optionally, the molar ratio of the lanthanide precursor to the organic ligand L is 2:2.75.

[0073] Optionally, the material may also include a solvent.

[0074] Optionally, the solvent is selected from at least one of acetonitrile, methanol, and nitromethane.

[0075] As one specific implementation method, the lanthanide polynuclear complex is obtained by the following means:

[0076]

[0077] Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu

[0078]

[0079] According to the last aspect of this application, an application of at least one of the above-mentioned C2 symmetric compounds and the above-mentioned lanthanide polynuclear complexes in a temperature sensor is provided.

[0080] In this application, a series of Ln ligands were synthesized using bipterdentate ligands with 2,6-pyridinediamide as the chelating site. 2n L 3n The device employs helical or tetrahedral cages; C2-symmetric ligands exhibit good sensitization ability for lanthanide ions (Ln = Nd, Eu, Yb), with emission spectra covering the visible and near-infrared regions. Specifically, by redshifting the excitation wavelength to the visible region, the emission spectra of lanthanide ions show good temperature response in the temperature range of 77K–298K, with a sensitivity of -0.54% / K; the d / f heterometallic organic polyhedral cage provides a new option for temperature-sensing supramolecular devices.

[0081] In this application, d / f heterometals refer to two different group d transition metals and group f rare earth metals contained in the same molecule.

[0082] In the context of this application, "C1~C6", "C6~C 12 "etc." indicates the number of carbon atoms contained in a compound or group.

[0083] In this application, the definition of "substituted alkyl" and "substituted aryl" refers to the number of carbon atoms inherent in the alkyl or aryl group, not the number of carbon atoms after substitution. For example, a C1-C6 substituted alkyl group refers to an alkyl group with a carbon number of C1-C6 in which at least one hydrogen atom is substituted by a substituent.

[0084] In the context of this application, the term "alkyl" refers to a group formed by losing any one hydrogen atom from a molecule of an alkane compound, including straight-chain alkanes, branched alkanes, cycloalkanes, and branched cycloalkanes.

[0085] In the context of this application, the term "aryl" refers to a group formed by the loss of any one hydrogen atom from an aromatic hydrocarbon molecule.

[0086] In the context of this application, the term "OTf" means CF3SO3—, which is the group formed by the loss of a hydrogen atom from trifluoromethanesulfonic acid.

[0087] In this application, "MLCT" refers to charge transfer from metal to ligand.

[0088] The beneficial effects that this application can produce include:

[0089] The C2 symmetric compound provided in this application incorporates a metal-organic group, exhibiting MLCT transition characteristics that redshift the excitation light, enabling visible light-excited lanthanide luminescence. Furthermore, the luminescence intensity shows good temperature responsiveness, significantly expanding the application range of lanthanide supramolecular polyhedral cages and providing possibilities for further application research. Attached Figure Description

[0090] Figure 1 The UV-Vis absorption (UV-L1), circular dichroism (CD-L1), excitation (Ex-L1), and fluorescence emission (Em-L1) spectra of ligand L1 in Example 1 of this application are shown (solvent: dimethyl sulfoxide; concentration: 1 × 10⁻⁶). -5 M).

[0091] Figure 2 The fluorescence emission spectrum of Ln4(L1)6 in Example 1 of this application (Ln = Eu, Yb, Nd; solvent acetonitrile, concentration 1 × 10⁻⁶) -5 M).

[0092] Figure 3 The fluorescence emission spectrum of Ln4(L1)6 as a function of temperature in Example 1 of this application (Ln = Eu, Yb; powder). Detailed Implementation

[0093] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0094] Unless otherwise specified, all chemical reagents and solvents used in the embodiments of this application are commercially available and have not been further purified before use.

[0095] The analysis method in the embodiments of this application is as follows:

[0096] NMR data were measured using a Bruker Biospin Avancce III 400MHz NMR analyzer (Germany) and an EJTEC 600S 600MHz NMR analyzer (Japan). High-resolution mass spectrometry (HMS) data were measured using an Impact II UHR-TOF mass spectrometer (Germany). Response data analysis was performed using Bruker isotope analysis software (version 4.3). UV-Vis spectroscopy was performed using a Shimadzu UV-2700 UV-Vis spectrophotometer. Excitation and emission spectroscopy were performed using an Edinburgh FS5 spectrometer (UK). Near-infrared spectroscopy data were measured using an Edinburgh FLS980 and FLS1000 spectrometer (UK).

[0097] Example 1

[0098] In this embodiment, ligand L1 is obtained in the following manner:

[0099]

[0100] Synthesis of intermediate 3:

[0101] (R)-6-(1-phenylethylcarbamoyl)pyridinecarboxylic acid (1.00 g, 3.70 mmol, 1.0 equiv) was dissolved in 10.0 mL of thionyl chloride, and 2 drops of DMF were added. The reaction mixture was stirred at room temperature for 12 h. After the reaction was complete, the remaining thionyl chloride was removed, and the resulting solid was dissolved in 100 mL of dry dichloromethane. 4-(trimethylsilyl)ethynylaniline (0.735 g, 3.88 mmol, 1.05 equiv) and triethylamine (2.0 mL, 14.4 mmol) were added. The mixture was stirred at 0 °C, and the reaction temperature was gradually increased to room temperature for 12 h, with the reaction monitored by thin-layer chromatography (TLC). After the reaction was complete, the reaction solvent was evaporated, and the resulting solid was purified by silica gel column chromatography using a gradient elution with ethyl acetate:petroleum ether = 1:5 (v:v) to give a pale yellow powder (1.47 g, 3.33 mmol, 90% yield). 1 H NMR (400MHz, CDCl3) δ9.55(s,1H),8.42(d,J=7.3Hz,1H),8.40(d,J=7.0Hz,1H),8.08(t,J=7.8Hz,1H),7.97(d,J=7.9Hz,1H),7.61(d,J=8.5Hz,2H),7 .46(d,J=8.6Hz,2H),7.44(d,J=10.5Hz,2H),7.38(t,J=7.5Hz,2H),7.31( t,J=7.2Hz,1H),5.36(m,J=7.0Hz,1H),1.66(d,J=3.2Hz,3H),0.26(s,9H). 13C NMR (100MHz, CDCl3) δ162.59,161.19,149.06,148.60,142.94,139.60,137.32,133.05,129.02,1 27.84,126.30,125.80,125.42,119.58,119.47,104.72,94.36,49.33,21.86,0.11.ESI-TOF-MS:C 26 H 27 N3O2Si[M+Na] + Simulated value: 464.1765, measured value: 464.1702. The above method yielded the target product intermediate 3.

[0102] Synthesis of intermediate 4:

[0103] Intermediate 3 (1.40 g, 3.17 mmol, 1.0 equiv) and potassium fluoride (0.920 g, 15.85 mmol, 5.0 equiv) were dissolved in 100.0 mL of methanol and stirred at room temperature for 6 h. The reaction was monitored by thin-layer chromatography (TLC). After the reaction was complete, the solvent was evaporated, and the resulting solid was purified by silica gel column chromatography with gradient elution using dichloromethane to give a white powder (1.11 g, 3.01 mmol, 95% yield). 1 H NMR (400MHz, CDCl3) δ9.51 (s, 1H), 8.44 (d, J = 7.7Hz, 1H), 8.42 (d, J = 7.0Hz, 1H), 8.10 (t, J = 7.8Hz, 1H), 7.88 (d, J = 8.0Hz, 1H), 7.65 (d, J = 8.6Hz, 2H), 7.52(d,J=8.6Hz,2H),7.46(d,J=7.3Hz,2H),7.41(t,J=7.5Hz,2H),7.33( t,J=7.1Hz,1H),5.37(p,J=7.0Hz,1H),3.09(s,1H),1.71(d,J=6.9Hz,3H). 13 C NMR (100MHz, CDCl3) δ162.65,161.30,149.08,148.55,142.94,139.55,137.57,133.11,128.9 6,127.77,126.27,125.81,125.41,119.83,118.37,83.29,77.38,49.24,21.82.ESI-TOF-MS:C 23 H 19 N3O2[M+Na] +Simulated value: 392.1369, measured value: 392.1343. The above method yielded intermediate 4.

[0104] Ligand L1 R Synthesis

[0105] Under an inert atmosphere, a mixture of bis(triethylphosphine) diiodoplatinum (205.6 mg, 0.3 mmol, 1.0 equiv), intermediate 4 (277 mg, 0.75 mmol, 2.5 equiv), and cuprous iodide (3.4 mg, 0.03 mmol, 0.1 equiv) was dissolved in 60 mL of a dichloromethane:triethylamine mixture of 4:1 (v / v). The mixture was stirred at 30 °C for 24 h, and the solvent was evaporated after the reaction was complete. The resulting solid was purified by silica gel column chromatography using a gradient elution with dichloromethane:methanol of 60:1 (v:v) to give an orange-yellow powder (257 mg, 0.22 mmol, yield 73%). 1 H NMR (400MHz, DMSO) δ10.85(s,2H),9.62(d,J=8.3Hz,2H),8.33(d,J=6.8Hz,2H),8.27–8.21(m,4H),7.71(d,J=8.4Hz,4H),7.46(d,J=7.6 Hz,4H),7.36(t,J=7.5Hz,4H),7.27–7.23(m,6H),5.31(q,J=7.0Hz,2H),2.21–2.05(m,12H),1.63(d,J=7.0Hz,6H),1.24–1.13(m,18H). 13 C NMR (100MHz, DMSO) δ162.68,161.48,149.11,148.78,144.18,139.78,135.01,130.78,128.4 2,126.86,126.18,125.15,124.92,121.33,54.97,48.19,21.86,16.19,16.02,15.84,8.30. 31 P NMR (162MHz, DMSO) δ11.13 (J (Pt-P) =2349Hz). ESI-TOF-MS:C 58 H 66 N6O4P2Pt[L1 R +H] + Simulated value: 1168.4345, Measured value: 1168.4338; [L1] R +Na] + Simulated value: 1190.4165, measured value: 1190.4159. The above method yielded ligand L1.R .

[0106] Synthesis of d / f heterometallic organopolyhedral cages: 30 μmol of organic ligand L1 and 20.5 μmol of Ln(OTf)3 were dissolved in 5 mL of acetonitrile. The mixture was stirred at 40 °C for 1 hour, and the reaction solution gradually changed from an initial suspension to a clear yellow solution. NMR characterization confirmed that there was no residual starting material and that a single product was obtained. Mass spectrometry confirmed the chemical structure of the product as Ln4L6(OTf). 12 The reaction solution was evaporated to dryness to obtain a yellow solid powder.

[0107] When the organic ligand is L1 and Ln is Lu, the resulting polyhedral cage is Lu4(L1)6. 1 H NMR (400MHz, CD3CN) δ10.19(s,2H),9.05(d,J=6.5Hz,2H),8.50(d,J=7.8Hz,2H),8.43(d,J=7.8Hz,2H),8.41–8.35(m,2H),7.39(d,J=8.6Hz,4H),7 .15(d,J=6.2Hz,6H),6.99(d,J=5.6Hz,4H),6.80(d,J=8.4Hz,4H),4.93( p,J=6.2Hz,2H),1.97(s,12H),1.63(d,J=6.9Hz,6H),1.09–0.95(m,18H). 13 C NMR(100MHz,CD3CN)δ167.68,166.23,147.83,147.45,143.75,142.76,133.31,131.87,129.41,128.36,128.3 1,127.06,126.70,126.39,123.32,121.80,120.14,116.96,109.12,53.08,21.63,17.36,17.19,17.01,8.80. 31 P NMR (162MHz, DMSO) δ 11.99 (J (Pt-P) =2350Hz).ESI-TOF-MS:[Lu4(L1)6(OTf)7-5HOTf] 5+ Simulated value: 1600.2389, measured value: 1600.2370; [Lu4(L1)6-6H] 6+ Simulated value: 1283.7138, measured value: 1283.7128; [Lu4(L1)6-5H] 7+ Simulated value: 1100.6131, measured value: 1100.6127; [Lu4(L1)6-4H] 8+Simulated value: 963.0372, measured value: 963.0367.

[0108] When the organic ligand is L1 and Ln is Nd, the resulting rare-earth polyhedral cage is Nd4(L1)6. ESI-TOF-MS: [Nd4(L1)6-6H] 6+ Simulated value: 1263.1939, measured value: 1263.1954; [Nd4(L1)6-5H] 7+ Simulated value: 1082.8807, measured value: 1082.8811; [Nd4(L1)6-4H] 8+ Simulated value: 974.6457, measured value: 947.6470.

[0109] When the organic ligand is L1 and Ln is Eu, the resulting rare-earth polyhedral cage is Eu4(L1)6. ESI-TOF-MS: [Eu4(L1)6(OTf)-5H] 6+ Simulated value: 1343.3468, measured value: 1343.3450; [Eu4(L1)6-5H] 7+ Simulated value: 1087.3156, measured value: 1087.3154; [Eu4(L1)6-4H] 8+ Simulated value: 951.5270, measured value: 951.5278; [Eu4(L1)6-3H] 9+ Simulated value: 845.9137, measured value: 845.9141; [Eu4(L1)6-2H] 10+ Simulated value: 761.4231, measured value: 761.4230.

[0110] When the organic ligand is L1 and Ln is Yb, the resulting rare-earth polyhedral cage is Yb4(L1)6. ESI-TOF-MS: [Yb4(L1)6(OTf)4-2H] 6+ Simulated value: 1382.5186, measured value: 1382.5196; [Lu4(L1)6(OTf)2-3H] 7+ Simulated value: 1142.3142, measured value: 1142.3249; [Lu4(L1)6-4H] 8+ Simulated value: 962.1610, measured value: 962.1615; [Lu4(L1)6-3H] 9+ Simulated value: 855.3661, measured value: 855.3661; [Lu4(L1)6-2H] 10+ Simulated value: 769.9302, measured value: 769.9305.

[0111] Example 2

[0112] The ligand L1 in Example 1 was subjected to UV-Vis absorption, circular dichroism spectroscopy, and fluorescence spectroscopy tests, as follows: Figure 1 As shown. From Figure 1 As can be seen from A, ligand L1 exhibits an absorption band centered on 2,6-pyridinediamide in the 220-305 nm range, and low-energy absorption bands in the 310-450 nm range from π→π*(C≡C) transitions caused by metal perturbations and d(Pt)→π*(RC≡C) metal-to-ligand charge transfer transitions (MLCT). R -L1 S The circular dichroism spectrum exhibits mirror-symmetric signals in the ranges of 225-250 nm and 250-400 nm. When excited at 365 nm, the ligand shows the strongest fluorescence emission peak at 550 nm. Figure 1 B).

[0113] Fluorescence testing was performed on the d / f heterometallic organic polyhedral cages in the examples, and typical results were obtained. Figure 2 As shown. From Figure 2 As can be seen, ligand L1 exhibits good sensitization performance for rare earth ions (Ln = Eu, Nd, Yb) emitted in the visible and near-infrared regions. The corresponding fluorescence emission intensity is significantly affected by temperature, showing a linear change with temperature, which can be used for temperature sensing. Taking Eu4(L1)6 as an example, when the excitation wavelength is 306 nm, the characteristic emission peaks of Eu (593, 615, 649, 695 nm) correspond to... 5 D0→ 7 F J (J = 0–4) was observed. Due to the presence of the organometallic chromophore in ligand L1, the excitation wavelength of Yb4(L1)6 redshifts to the visible region (400–500 nm). When the excitation wavelength is 445 nm, the characteristic emission peak of Yb (979 nm) corresponds to 5 F 5 / 2 → 2 F 7 / 2 It was observed. Similarly, the excitation wavelength of Nd₄(L₁)₆ redshifted into the visible light region (400-500 nm). When the excitation wavelength was 450 nm, the characteristic emission peak of Nd (870-1400 nm) corresponded to... 4 F 3 / 2 → 4 I J (J = 9 / 2, 11 / 2, 13 / 2) were observed.

[0114] Temperature-dependent fluorescence testing was performed on the d / f heterometallic organic polyhedral cages in the examples. Figure 3As shown. Taking Eu4(L1)6 as an example, when the excitation wavelength is 366 nm, as the temperature increases from 77 K to 300 K, the emission peak intensity (I) of Eu at 615 nm gradually decreases, and I / I 300K It exhibits a linear relationship with temperature, with a temperature response factor of -0.54% / K, comparable to that of some organic Pt-based supramolecular macrocyclic materials. Taking Yb₄(L₁)₆ as an example, when the excitation wavelength is 505 nm, as the temperature increases from 77 K to 300 K, the emission peak intensity (I) of Yb at 985 nm gradually decreases, with I / I₁ / I₂... 300K It exhibits a linear relationship with temperature, with a temperature response factor of -0.17% / K.

[0115] Example 3

[0116] In this embodiment, ligand L2 is obtained in the following manner.

[0117]

[0118] Synthesis of intermediate 3:

[0119] (R)-6-(1-phenylethylcarbamoyl)pyridinecarboxylic acid (1.00 g, 3.70 mmol, 1.0 equiv) was dissolved in 10.0 mL of thionyl chloride, and 2 drops of DMF were added. The reaction mixture was stirred at room temperature for 12 h. After the reaction was complete, the remaining thionyl chloride was removed, and the resulting solid was dissolved in 100 mL of dry dichloromethane. 4-(trimethylsilyl)ethynylaniline (0.735 g, 3.88 mmol, 1.05 equiv) and triethylamine (2.0 mL, 14.4 mmol) were added. The mixture was stirred at 0 °C, and the reaction temperature was gradually increased to room temperature for 12 h, with the reaction monitored by thin-layer chromatography (TLC). After the reaction was complete, the reaction solvent was evaporated, and the resulting solid was purified by silica gel column chromatography using a gradient elution with ethyl acetate:petroleum ether = 1:5 (v:v) to give a pale yellow powder (1.47 g, 3.33 mmol, 90% yield). 1 H NMR (400MHz, CDCl3) δ9.55(s,1H),8.42(d,J=7.3Hz,1H),8.40(d,J=7.0Hz,1H),8.08(t,J=7.8Hz,1H),7.97(d,J=7.9Hz,1H),7.61(d,J=8.5Hz,2H),7 .46(d,J=8.6Hz,2H),7.44(d,J=10.5Hz,2H),7.38(t,J=7.5Hz,2H),7.31( t,J=7.2Hz,1H),5.36(m,J=7.0Hz,1H),1.66(d,J=3.2Hz,3H),0.26(s,9H).13 C NMR (100MHz, CDCl3) δ162.59,161.19,149.06,148.60,142.94,139.60,137.32,133.05,129.02,1 27.84,126.30,125.80,125.42,119.58,119.47,104.72,94.36,49.33,21.86,0.11.ESI-TOF-MS:C 26 H 27 N3O2Si[M+Na] + Simulated value: 464.1765, measured value: 464.1702. The above method yielded the target product intermediate 3.

[0120] Synthesis of intermediate 4:

[0121] Intermediate 3 (1.40 g, 3.17 mmol, 1.0 equiv) and potassium fluoride (0.920 g, 15.85 mmol, 5.0 equiv) were dissolved in 100.0 mL of methanol and stirred at room temperature for 6 h. The reaction was monitored by thin-layer chromatography (TLC). After the reaction was complete, the solvent was evaporated, and the resulting solid was purified by silica gel column chromatography with gradient elution using dichloromethane to give a white powder (1.11 g, 3.01 mmol, 95% yield). 1 H NMR (400MHz, CDCl3) δ9.51 (s, 1H), 8.44 (d, J = 7.7Hz, 1H), 8.42 (d, J = 7.0Hz, 1H), 8.10 (t, J = 7.8Hz, 1H), 7.88 (d, J = 8.0Hz, 1H), 7.65 (d, J = 8.6Hz, 2H), 7.52(d,J=8.6Hz,2H),7.46(d,J=7.3Hz,2H),7.41(t,J=7.5Hz,2H),7.33( t,J=7.1Hz,1H),5.37(p,J=7.0Hz,1H),3.09(s,1H),1.71(d,J=6.9Hz,3H). 13 C NMR (100MHz, CDCl3) δ162.65,161.30,149.08,148.55,142.94,139.55,137.57,133.11,128.9 6,127.77,126.27,125.81,125.41,119.83,118.37,83.29,77.38,49.24,21.82.ESI-TOF-MS:C 23 H 19 N3O2[M+Na] +Simulated value: 392.1369, measured value: 392.1343. The above method yielded intermediate 4.

[0122] L2 ligand R Synthesis

[0123] Under an inert atmosphere, a mixture of 4,4'-di-tert-butyl-(2,2'-bipyridine)platinum(II) chloride (160.3 mg, 0.3 mmol, 1.0 equiv), intermediate 4 (277 mg, 0.75 mmol, 2.5 equiv), and cuprous iodide (3.4 mg, 0.03 mmol, 0.1 equiv) was dissolved in 60 mL of a dichloromethane:triethylamine mixture of 4:1 (v / v). The mixture was stirred at 30 °C for 24 h, and the solvent was evaporated after the reaction was complete. The resulting solid was purified by silica gel column chromatography using a gradient elution with dichloromethane:methanol of 60:1 (v:v) to give an orange powder (288 mg, 0.24 mmol, 80% yield). 1 H NMR(400MHz,DMSO)δ10.90(s,2H),9.63(d,J=8.2Hz,2H),9.38(d,J=5.0Hz,2H),8 .67(s,2H),8.35(d,J=6.5Hz,2H),8.28–8.21(m,4H),7.92(d,J=5.4Hz,2H),7.79( d,J=8.3Hz,4H),7.54(d,J=8.1Hz,4H),7.46(d,J=7.5Hz,4H),7.35(d,J=7.5Hz,4 H),7.24(t,J=7.2Hz,2H),5.39–5.24(m,2H),1.64(d,J=6.9Hz,6H),1.43(s,18H). 13 C NMR (100MHz, DMSO) δ164.75,163.09,161.97,156.25,150.30,149.54,149.15,144.62,140.23,136.17,132.43,12 8.83,127.28,126.61,125.62,125.49,125.36,123.99,121.78,121.50,48.62,36.47,30.34,22.26.ESI-TOF-MS:C 64 H 60 N8O4Pt[L1+H] + Simulated value: 1201.4478, measured value: 1201.4473; [L1+Na] + Simulated value: 1223.4297, measured value: 1223.4288. The above method yielded the ligand L2.R .

[0124] Synthesis of d / f heterometallic organopolyhedral cages: 30 μmol of organic ligand L2 and 20.5 μmol of Ln(OTf)3 were dissolved in 5 mL of acetonitrile. The mixture was stirred at 40 °C for 1 hour, and the reaction solution gradually changed from an initial suspension to a clear yellow solution. NMR characterization confirmed that there was no residual starting material and that a single product was obtained. Mass spectrometry confirmed the chemical structure of the product as Ln2L3(OTf). 12 The reaction solution was evaporated to dryness to obtain a yellow solid powder.

[0125] When the organic ligand is L2 and Ln is Lu, the resulting polyhedral cage is Lu2(L2)3. 1 H NMR(400MHz,CD3CN)δ9.92(s,2H),9.29(d,J=6.0Hz,2H),9.15(d,J=6.5Hz,2 H),8.52(d,J=7.9Hz,2H),8.47(t,J=7.8Hz,2H),8.40(d,J=7.5Hz,2H),8.32 (s,2H),7.66(d,J=7.7Hz,2H),7.12–7.03(m,10H),6.99(d,J=6.5Hz,4H),6. 90(d,J=8.8Hz,4H),5.05–4.88(m,2H),1.62(d,J=7.1Hz,6H),1.44(s,18H). 13 C NMR (100MHz, CD3CN) δ167.88,165.78,165.74,157.22,151.03,147.60,146.91,143.78,143.19,133.30,132.50,129.39,128.37,127.4 6,127.34,126.47,126.24,123.28,122.04,121.81,120.10,116.92,53.26,36.70,30.17,21.74.ESI-TOF-MS:[Lu2(L2)3(OTf)3-2HOTf] 3+ Simulated value: 1365.7120, measured value: 1365.7104; [Lu2(L2)3-3H] 3+ Simulated value: 1315.7255, measured value: 1315.7243; [Lu2(L2)3-2H] 4+ Simulated value: 987.0460, measured value: 987.0451; [Lu2(L2)3-H] 5+ Simulated value: 789.8382, measured value: 789.8369;

[0126] When the organic ligand is L2 and Ln is Nd, the resulting rare-earth polyhedral cage is Nd2(L2)3. ESI-TOF-MS: [Nd2(L2)3(OTf)3] 3+ Simulated value: 1445.3322, measured value: 1444.9997; [Nd2(L2)3(OTf)2] 4+ Simulated value: 1046.5107, measured value: 1046.5117; [Nd2(L2)3(OTf)1] 5+ Simulated value: 807.6184, measured value: 807.6190; [Nd2(L2)3] 6+ Simulated value: 648.0230, measured value: 648.0241.

[0127] When the organic ligand is L2 and Ln is Yb, the resulting rare-earth polyhedral cage is Yb2(L2)3. ESI-TOF-MS: [Yb2(L2)3(OTf)3] 3+ Simulated value: 1465.6853, measured value: 1465.6801; [Yb2(L2)3(OTf)2] 4+ Simulated value: 1061.2748, measured value: 1061.2755; [Yb2(L2)3(OTf)1] 5+ Simulated value: 819.2293, measured value: 819.2301; [Yb2(L2)3] 6+ Simulated value: 657.6988, measured value: 657.8632.

[0128] Example 4

[0129] The ligand L2 in Example 3 was subjected to UV-Vis absorption, circular dichroism spectroscopy, and fluorescence spectroscopy. Ligand L2 exhibited an absorption band centered on 2,6-pyridinediamide in the 220-305 nm range, and low-energy absorption bands in the 310-450 nm range from π→π*(C≡C) transitions and d(Pt)→π*(RC≡C) metal-to-ligand charge transfer transitions (MLCT) originating from metal perturbations. R -L2 S The circular dichroism spectrum exhibits a mirror-symmetric signal in the 225-400 nm range. When excited at 329 nm, the ligand shows the strongest fluorescence emission peak at 609 nm.

[0130] Fluorescence tests were performed on the d / f heterometallic organic polyhedral cages in the examples. Taking Nd₄(L₁)₆ as an example, when the excitation wavelength was 440 nm, the characteristic emission peaks of Nd (871, 1056, 1327 nm) corresponded to... 4 F 3 / 2 → 4 IJ (J = 9 / 2, 11 / 2, 13 / 2) were observed. When the excitation wavelength was 440 nm, the characteristic emission peak of Yb (978 nm) corresponded to... 5 F 5 / 2 → 2 F 7 / 2 It was observed.

[0131] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A kind C2 Symmetrical compounds, characterized in that, It has the structural formula shown in Equation I: Equation I Wherein, R is selected from any one of C1-C6 alkyl groups and substituted C1-C6 alkyl groups; Selected from any of the following groups: 、 ; R1 is selected from H and any one of C1 to C6 alkyl groups; R5 is selected from any one of C1 to C6 alkyl groups; R2 is selected from any one of C and N. Where M is Pt; The substituents in the substituted C1-C6 alkyl group are selected from C6-C6. 12 Any of the aryl groups.

2. As described in claim 1 C2 Symmetrical compounds, characterized in that, Selected from any of the following groups: 、 、 、 、 ； R is selected from any of the following groups: 。 3. The claim 1 or 2 C2 A method for preparing symmetrical compounds, characterized in that, The preparation method includes: A mixture containing halogen compound i and alkynyl compound ii is subjected to a substitution reaction to obtain the aforementioned product. C2 Symmetrical compounds; The halogen compound i is selected from any one of compounds having the structural formula shown in Formula IV and compounds having the structural formula shown in Formula V; Formula IV Formula V The alkynyl compound ii is selected from any one of the compounds having the structural formula shown in Formula VI; Formula VI Where X is selected from halogens; M is Pt.

4. The preparation method according to claim 3, characterized in that, The conditions for the substitution reaction are: temperature 20~40℃; time 12h-48h; The molar ratio of the halogen compound i to the alkynyl compound ii is 1:2~4; The mixture also includes a catalyst and an acid-binding agent; The catalyst is selected from at least one of cuprous iodide and cuprous chloride; The acid-binding agent is selected from at least one of triethylamine, diethylamine, pyridine, N,N-diisopropylethylamine, triethanolamine, and tetrabutylammonium bromide; The molar ratio of the catalyst to the halogen compound i is 1:0.05~0.2; The molar ratio of the acid-binding agent to the halogen compound i is 1:200~400.

5. A lanthanide polynuclear complex, characterized in that, The lanthanide polynuclear complexes have the general formula shown in Formula VII: Ln 2n L 3n Equation VII Wherein, Ln is selected from any of the lanthanide elements, and n is selected from 1 or 2; L is an organic ligand selected from those described in claim 1 or 2. C2 Symmetrical compounds, prepared by the method according to claim 3 or 4 C2 One type of symmetrical compound; In this case, the nitrogen atom in L is coordinated with Ln; The lanthanide polynuclear complexes are selected from d / f heterometallic organospirals or d / f heterometallic organotetrahedral cages; The nitrogen atom in L is coordinated with Ln at the vertices of the helix or tetrahedron; The d / f heterometallic organic tetrahedral cage is selected from any of the compounds having the structural formula shown in Formula VIII; Formula VIII The d / f heterometallic organic spirochete is selected from any of the compounds having the structural formula shown in Formula IX; Formula IX in, Let Ln be the value.

6. The lanthanide polynuclear complex according to claim 5, characterized in that, Ln is selected from any one of Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

7. The method for preparing the lanthanide polynuclear complex according to claim 5 or 6, characterized in that, The preparation method includes: The lanthanide polynuclear complex can be obtained by reacting materials containing lanthanide precursors and organic ligand L at 40–60 °C.

8. The preparation method according to claim 7, characterized in that, The lanthanide precursor is selected from Ln trifluoromethanesulfonic acid compounds; The trifluoromethanesulfonic acid compound of Ln is selected from any one of Pr(OTf)3, Nd(OTf)3, Sm(OTf)3, Eu(OTf)3, Gd(OTf)3, Tb(OTf)3, Dy(OTf)3, Ho(OTf)3, Er(OTf)3, Tm(OTf)3, Yb(OTf)3, and Lu(OTf)3.

9. The preparation method according to claim 7, characterized in that, The molar ratio of the lanthanide precursor to the organic ligand L is 2:2.5~3.5; The number of moles of the lanthanide precursor is expressed as the number of moles of the lanthanide element.

10. The claim 1 or 2 C2 Application of at least one of the symmetric compounds, the lanthanide polynuclear complexes of claim 5 or 6, in temperature sensor devices.

Images