271 results about "Salicylaldehyde" patented technology

The invention relates to the field of coatings, and discloses an outer wall light radiation heat preservation and heat insulation decorative sheet and a preparation method thereof.A radiation refrigeration layer on the surface of the outer wall light radiation heat preservation and heat insulation decorative sheet comprises modified acrylate resin, silicon dioxide, ground calcium carbonate, talcum powder, modified hollow glass beads and auxiliaries; the modified acrylate resin is prepared by copolymerizing perfluorooctyl ethyl acrylate, methyl methacrylate, modified isocyano ethyl methacrylate and vinyltriethoxysilane, and the modified isocyano ethyl methacrylate is prepared by using salicylaldehyde and benzothiazole-2-formaldehyde as well as 1, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate as an initiator and using 2, 3, 4-trimethyl-1, 3-pentanediol monoisobutyrate as an initiator. The preparation method comprises the following steps: reacting amino groups at two ends of 1, 5-naphthylenediamine with DOPO, carrying out nucleophilic addition reaction with DOPO, and grafting with isocyano ethyl methacrylate. The modified hollow glass beads are prepared by using tetrabutyl titanate as a titanium source through a sol-gel method, and the prepared radiation refrigeration layer has the super-amphiphobic self-cleaning effect, the radiation refrigeration effect is good, and meanwhile the flame retardant property and the antibacterial effect are excellent.

The invention discloses an antibacterial material rich in a bismuth metal organic framework and a preparation method thereof, the method comprises the following steps: adding an indole monomer and an alcohol monomer into a solvent, and then adding nitrosalicylaldehyde into the solvent to obtain a spiropyran compound; the preparation method comprises the following steps: adding humic acid into a binary solvent consisting of dioxane and butanol to obtain a mixed solution; the ratio of the mass of the humic acid to the volume of the binary solvent is (2-3): (20-40) g / ml; sequentially adding a bismuth source, 2-bromo-5-(trifluoromethyl) pyridine and 4-(trifluoromethyl) phenylboronic acid into the mixed solution to obtain a bismuth metal organic framework; and adding the spiropyran compound into the bismuth metal organic framework to obtain the antibacterial material rich in the bismuth metal organic framework. The antibacterial capability of the antibacterial material is improved.

The invention discloses a natural plant-based spinning yarn and a preparation method thereof, and relates to the technical field of spinning yarns. When the natural plant-based spinning yarn is prepared, palm fibers are pretreated with a sodium chlorite solution and a sodium hydroxide solution, and pretreated palm fibers are prepared; reacting the pretreated palm fibers with ammonium dihydrogen phosphate to prepare phosphorylated modified palm fibers; reacting the phosphorylated modified palm fibers with calcium nitrate, diammonium hydrogen phosphate and allylphosphonic acid to grow hydroxyapatite in situ, so as to prepare hydroxyapatite composite palm fibers; 4-allyl thiosemicarbazide reacts with salicylaldehyde to prepare an antibacterial agent intermediate, and the antibacterial agent intermediate is complexed with copper ions to prepare an antibacterial agent; grafting an antibacterial agent and an anti-aging agent on the hydroxyapatite composite palm fibers to prepare modified palm fibers; and spinning the modified palm fiber to obtain the natural plant-based spun yarn. The prepared natural plant-based spinning yarn has the advantages of being high in breaking strength, antibacterial, flame-retardant and anti-aging.

The invention discloses an OMTD photoelectric mapping transparent display film with adjustable light transmittance and a preparation method, and belongs to the technical field of transparent display films. The transparent display film comprises an electric control dimming film layer, a fluorescent layer, an adhesive layer and a release material layer, wherein the fluorescent layer comprises the following raw materials in parts by weight: 80-100 parts of polyurethane resin, 2-5 parts of a fluorescent agent, 3-6 parts of a dispersing agent, 4-8 parts of a modified anti-aging agent, 1-10 parts of a curing agent and 200 parts of a solvent; according to the invention, p-phenylenediamine and 4-(diethylamino) salicylaldehyde react to prepare a fluorescent small molecule substance, and then the fluorescent small molecule substance is introduced into a polyurethane chain to finally prepare the fluorescent agent. The prepared transparent display film has excellent fluorescence performance, transparency and anti-aging performance.

The invention belongs to the technical field of organic synthesis, and particularly relates to a salicylaldehyde hydrazone bridged organic boron photoinitiator as well as a preparation method and application thereof. The structural formula of the salicylaldehyde hydrazone bridged organic boron photoinitiator is as shown in formula I, wherein R is H or halogen atom; the salicylaldehyde hydrazone bridged organic boron photoinitiator has a vertical spatial configuration formed by a seven-membered ring and a six-membered ring. A framework of the salicylaldehyde hydrazone bridged organic boron photoinitiator has a unique vertical spatial configuration, generation of a spinning triplet state can be effectively promoted through orbital angular momentum regulation and control, and a more favorable excited state characteristic is provided for a photoinitiation process. The absorption wavelength and the emission spectrum of an LED light source are well overlapped, and high reaction activity can still be kept under the conditions of low irradiation intensity (lt, 60 mW / cm) and short exposure time (lt, 60 s). In addition, the preparation method of the salicylaldehyde hydrazone bridged organic boron photoinitiator is simple and efficient, the raw material cost is low, and the salicylaldehyde hydrazone bridged organic boron photoinitiator has a wide application prospect.

The invention relates to the field of printing inks and discloses a wear-resistant and scratch-resistant printing ink, a preparation method thereof, and an application thereof. The printing ink comprises: a modified aqueous polyurethane emulsion, a modified mica sheet, a pigment, an additive, and deionized water; the modified aqueous polyurethane emulsion is prepared by introducing a double-terminal hydroxyl chain extender into a polymer; the double-terminal hydroxyl chain extender is reacted with a Schiff base intermediate obtained by reacting salicylaldehyde and p-aminobenzyl alcohol and isocyanoethyl methacrylate, and the obtained double-bonded Schiff base intermediate is reacted with 1,1,3,3-tetramethyldisiloxane to prepare the ink; the modified mica sheet is reacted with triethylenetetramine, formaldehyde, and acetone, and then formaldehyde is added under alkaline conditions for polycondensation, the obtained cationic polymer and glutaraldehyde are prepared into the cationic mica sheet, and finally polyaniline is grown on the surface of the mica sheet through interfacial polymerization. The ink prepared by the invention has good adhesion, high hardness, and excellent water resistance, wear resistance, heat resistance, antistatic properties, and antibacterial properties.

A volatile composition dispenser includes a reservoir comprising a volatile composition; and an evaporative surface in fluid communication with the reservoir. The volatile composition comprises a first fragrance material that is a meta-(C1-C4 alkoxy)salicylaldehyde, and the first fragrance material is present in an amount of at least 0.0005%, by weight of the volatile composition. A process of treating an environment with a volatile composition dispenser includes providing a volatile composition dispenser and providing the meta-(C1-C4 alkoxy)salicylaldehyde to the environment. A weight loss of the volatile composition over less than 11 days ranges from 7% to 20%.

The embodiment of the invention provides a preparation method of methylene-bridged substituted phenol substituted by hydroxyl ortho-hydroxymethyl, and the preparation method comprises the following steps: A1, reacting substituted phenol with formaldehyde in the presence of a Lewis acid catalyst to prepare a substituted salicylaldehyde compound (2); a2, carrying out condensation reaction on the substituted salicylaldehyde compound (2) in a system containing formaldehyde and a Bronsted acid catalyst to prepare a methylene-bridged substituted salicylaldehyde compound (3); and A3, reducing the methylene-bridged substituted salicylaldehyde compound (3) to prepare methylene-bridged substituted phenol (4) with hydroxyl ortho-hydroxymethyl substituted. According to the embodiment of the invention, the yield and the chemical purity of the prepared methylene-bridged substituted phenol substituted by hydroxyl ortho-hydroxymethyl can be improved. According to other embodiments of the invention, the invention also provides a preparation method of the polyphenol compound containing multiple phenol units.

The invention discloses a phosphorus-silicon type Schiff base derivative flame retardant and a preparation method and application thereof.The preparation method comprises the steps that salicylaldehyde and 1, 3-bis (3-aminopropyl)-1, 1, 3, 3-tetramethyldisiloxane react to obtain silicon-containing Schiff base, then P-H on hypophosphorous acid substances and-C = N-on the silicon-containing Schiff base are subjected to an addition reaction, and the phosphorus-silicon type Schiff base derivative flame retardant is obtained. The phosphorus-silicon type Schiff base derivative flame retardant is prepared. The flame retardant contains a plurality of groups such as-OH,-NH-and the like, can achieve molecular-level dispersion in a high polymer material, and plays an efficient flame-retardant role. The flame retardant has a gas-phase and condensed-phase dual-phase flame retardant effect: in the gas phase, the effects of dilution and free radical capture are exerted; and in a condensed phase, char formation can be promoted and a barrier effect can be exerted. In addition, due to the existence of organic silicon, a compact carbon layer with a specific-Si-O-bond or-Si-C-bond of siloxane can be generated during combustion, the protection effect of oxygen isolation and heat insulation is achieved, and the condensed phase flame retardant effect is enhanced. The phosphorus-silicon type Schiff base derivative flame retardant has a wide application prospect and can be applied to flame-retardant modification of polyurethane and epoxy resin.

The invention relates to the field of copper plating solutions, and provides a low-stress chemical copper plating solution for a glass substrate and a preparation method of the low-stress chemical copper plating solution. The invention discloses a copper ion carboxyl chelate, which is composed of copper ion carboxyl chelate, 2, 2 '-bipyridine, polyethylene glycol-8000, lauryl sodium sulfate, a sodium carbonate buffer agent, deionized water and a pretreatment solvent, and the copper ion carboxyl chelate is prepared by chelating a polyacrylate-itaconic acid copolymer with copper chloride and then carrying out stepwise cross-linking with epichlorohydrin and N, N'-methylene bisacrylamide. The copper-bis-salicylaldehyde ethylenediamine complex is obtained by reacting bis-salicylaldehyde ethylenediamine with copper acetate, crystallizing and purifying. The preparation method comprises the steps of solvent premixing, chelating activation, staged additive integration, pH dynamic regulation and control and plating solution purification, through nitrogen protection, high-shear stirring and accurate pH regulation, the problems that a traditional chemical copper plating layer is high in stress and poor in conductivity are solved, and the method is suitable for high-precision glass substrate surface metallization.

The invention discloses quick heat-conducting precoated sand and a preparation process thereof, and relates to the technical field of precoated sand, the quick heat-conducting precoated sand comprises the following raw materials by weight: 100-105 parts of crude sand, 6-8 parts of a modified resin prepolymer, 2-4 parts of modified POE, 3.5-4.5 parts of a lubricant, and 3-5 parts of nano silicon nitride. The modified POE has a relatively strong high-temperature toughening effect on the modified resin prepolymer, can also form chemical crosslinking with the modified resin prepolymer, and has relatively strong compatibility with other raw materials in the precoated sand. The modified resin prepolymer is obtained by heating and ring-opening polymerization of a benzoxazine monomer obtained by reaction of 5-nitrosalicylaldehyde, 2, 4-bis (trifluoromethyl)-5-pyrimidinyl ethyl formate, paraformaldehyde, furfuryl amine and the like, the curing temperature of the modified resin prepolymer is reduced, the thermal stability is improved, and improvement of the high temperature resistance of the precoated sand is facilitated.

Embodiments of the present disclosure describe metal organic framework (MOF)-like composite material (MOFite) including a salicylaldehydate-based iron metal organic framework composition and graphite, a lithium-ion battery including a cathode and an anode including a salicylaldehydate-based iron metal organic framework composition and graphite, and a scalable synthesis methods for salicylaldehydate-based metal-organic frameworks (SA-MOFs), specifically Fe-Tp, and their applications in lithium-ion batteries (LIBs).

The preparation method comprises the following steps: in the presence of a cobalt catalyst and a salicylaldehyde Schiff base ligand, carrying out carbonyl synthesis reaction on C5-C20 olefin and synthesis gas at a certain reaction temperature and pressure to generate C6-C21 aldehyde. The salicylaldehyde Schiff base coordination cobalt catalyst is introduced, the electronic structure of the catalyst is changed, the capacity of the catalyst for adsorbing and activating olefin and synthesis gas is improved, the reaction temperature and pressure can be reduced, the high-carbon aldehyde yield is greatly increased, and the method has good application prospects and industrial application potential in the field of petrochemical engineering.

The invention discloses an antibacterial sanitary towel surface layer material and a sanitary towel, and relates to the technical field of daily necessities. When the antibacterial sanitary towel surface layer material is prepared, bamboo pulp fibers and a salicylaldehyde Schiff base calcium complex react to prepare modified bamboo pulp fibers; the preparation method comprises the following steps: enabling 3-imidazole-1-propionic acid and 1-chlorohexane to react to prepare propionyl imidazolium salt; the preparation method comprises the following steps: carrying out reaction on China hemp fibers and propionyl imidazolium salt to prepare modified China hemp fibers; the preparation method comprises the following steps: polymerizing vinyl perfluoro caprylate and 5-allylimidazolidine-2, 4-diketone, and chloridizing with sodium hypochlorite to obtain an antibacterial water-repellent finishing agent; the modified bamboo pulp fibers and the modified China hemp fibers are subjected to opening, carding, lapping and overlapping respectively and then subjected to spunlace reinforcement, a composite surface layer is prepared, the composite surface layer is coated with an antibacterial water-repellent finishing agent and dried, and the antibacterial sanitary towel surface layer material is prepared. The antibacterial sanitary towel surface layer material prepared by the invention has excellent antibacterial property and anti-back-permeation property.

This invention provides a polynuclear metal cluster based on salicylaldehyde acetal-2-thiophenol ligand, its preparation method, and its application. The chemical formula of the polynuclear metal cluster is Co4(C 13 H9NOS)6·2CH3CN·CH3OH, where C 13 H9NOS is salicylaldehyde acetal-2-thiophenol, with Co forming a six-coordinate octahedral configuration with N, O, and S. The salicylaldehyde acetal-2-thiophenol ligand in the polynuclear metal cluster of this invention can effectively stabilize the active center of metallic cobalt, resulting in a polynuclear metal cluster with significant OER activity and broad prospects for practical applications.

The invention relates to a fertilization process for fruit tree planting, and belongs to the technical field of fruit tree planting processes. The fertilizing process comprises the following steps: digging a fertilizing ditch on one side of a main stem of a fruit tree, applying a slow-release fertilizer, and covering soil after the slow-release fertilizer is applied. The distance between the fertilization furrows and main stems of the fruit trees is 30-50 cm, the fertilization amount of the slow-release fertilizer is 5-10 kg per fruit tree, and the slow-release fertilizer is prepared from graphene, amino acid, urea, monopotassium phosphate, calcium nitrate and modified salicylaldehyde. According to the invention, on the basis of the slow-release fertilizer, a fertilization process during planting is reasonably blended, and the fertilization distance and the fertilization amount of the slow-release fertilizer are subjected to targeted range matching, so that the slow-release fertilizer can be effectively absorbed by a root system, and waste of the fertilizer is avoided. The proper fertilization distance can encourage the outward expansion of the root system, so that the healthy growth of the root system is facilitated, and the stress resistance of the fruit tree is enhanced. The reasonable fertilizing amount can further promote the growth of fruit trees and improve the yield of the fruit trees and the quality of fruits.

The invention belongs to the technical field of chemical pharmaceuticals, and discloses a synthesis process of a benzazin heavy key intermediate 2-ethyl benzofuran, which comprises the following steps: step S10, taking salicylaldehyde SM1 and chloroacetone SM2 as initial raw materials, and adding an alcohol solvent and a strong alkali solution to synthesize a compound A; step S20, carrying out hydrogenation reduction reaction on the compound A to obtain 2-ethylbenzofuran TM; raw materials used in the scheme are cheap and easy to obtain, reaction steps are few, and synchronous recovery of the solvent is facilitated; reaction conditions are mild, equipment requirements are low, and production cost is low; the method is simple to operate, small in environmental pollution and suitable for industrial large-scale production; the invention solves the problem that the existing benzarone synthesis process is difficult for industrial scale production.

The invention belongs to the technical field of high polymer chemistry and material science, and particularly relates to application of a salicylaldehyde Schiff base chiral polymer in iron and copper ion detection, and the structural formula of the salicylaldehyde Schiff base chiral polymer is one of the following structures shown in the specification. . The salicylaldehyde Schiff base chiral polymer has high selectivity to copper ions and iron ions, and qualitative detection of the copper ions and the iron ions can be achieved according to changes of ultraviolet absorption spectrums, digital circular dichroism spectrums and fluorescence spectrums before and after coordination of the salicylaldehyde Schiff base chiral polymer with the copper ions and the iron ions.

The present invention discloses a class of perfluorophenyl-substituted salicylaldimine nickel complexes, a preparation method thereof, and an application thereof in highly active catalytic norbornene polymerization. The preparation method includes the following steps: first metallizing a neutral ligand with sodium hydride, then reacting it with a nickel metal raw material compound in an organic medium, and then obtaining the target compound through filtration, concentration, and recrystallization steps. The perfluorophenyl-substituted salicylaldimine nickel complex of the present invention is a highly efficient norbornene addition polymerization catalyst. The perfluorophenyl-substituted salicylaldimine nickel complex of the present invention has very obvious advantages: the raw materials are easily available, the synthesis route is simple, the product yield is high, the polymerization performance can be regulated by adjusting the substituent structure, and it has a wide application prospect. Its structural formula is shown as follows:

The invention discloses a high-load cobalt monatomic catalyst with a three-dimensional confinement structure as well as a preparation method and application of the high-load cobalt monatomic catalyst. A three-dimensional cyclodextrin-based covalent organic framework 3D-CD-COF, which is constructed by seven-(6-amino-6-deoxy)-beta-cyclodextrin (7ACD) and aromatic dicarboxaldehyde (terephthalaldehyde or 4, 4 '-biphenyl dicarboxaldehyde), is used as a carrier, multiple coordination sites are constructed through salicylaldehyde grafting, and high-loading anchoring of cobalt single atoms is realized; cobalt single atoms are uniformly dispersed in a three-dimensional intercommunicated pore channel in a CoN1O3 coordination form, the loading capacity reaches 13.0-14.0%, and a three-dimensional confinement structure can inhibit four-electron oxygen evolution side reaction. The catalyst has high hydrogen peroxide Faraday efficiency and high yield, compared with Co-CD without a three-dimensional confinement structure, the activity and selectivity are remarkably improved, and an efficient technical scheme is provided for electrochemical preparation of hydrogen peroxide.

The invention relates to the field of paperboard, in particular to a multi-layer composite waterproof and explosion-proof corrugated paperboard and a preparation method thereof. An explosion-proof film layer, a foam board layer, a reinforcing fiber mesh layer and a corrugated paperboard layer are sequentially bonded with a green flame-retardant adhesive to obtain a corrugated paperboard, and a modified halloysite nanotube and a composite waterborne polyurethane are compounded as a protective coating to be coated on the corrugated paperboard; cross-linked oxidized starch is compounded with the composite waterborne polyurethane and the modified halloysite nanotube to obtain a flame-retardant adhesive; the halloysite nanotube is modified by firstly amminating its surface with 3-aminopropyltriethoxysilane, and then graphene oxide is loaded on its surface by electrostatic self-assembly to obtain a hybrid flame-retardant filler, namely, a composite halloysite nanotube, which is then modified with aspartic acid and then reactively grafted with a salicylaldehyde Schiff base flame retardant containing a hydroxyl group.

The present invention relates to the technical field of luminescent materials, and specifically relates to a transition metal antibacterial fluorescent waterborne polyurethane material, a preparation method thereof, and an application thereof. First, salicylaldehyde and ethanolamine are used as reactants to obtain Schiff base salicylaldehyde ethanolamine by reflux heating; salicylaldehyde ethanolamine is used as a ligand to reflux with zinc acetate to prepare a blue fluorescent transition metal complex. The polymer polyol and isocyanate are reacted and condensed, and then a hydrophilic group is introduced through a chain extension reaction and then reacted with transition metal complex powders in different proportions, and they are incorporated into the polyurethane molecular chain segment, and then emulsified and the organic solvent is removed to obtain an antibacterial blue fluorescent waterborne polyurethane material. The fluorescent waterborne polyurethane prepared by the present invention has the characteristics of good storage stability, high fluorescence intensity, environmental friendliness, high antibacterial rate, etc., and has the advantages of convenient use, recyclability, wide application fields, etc.

The invention relates to the technical field of catalysts for synthesizing ethylene propylene rubber, and discloses a vanadium-based catalyst composition and a preparation method and application thereof.The vanadium-based catalyst composition comprises a vanadium catalyst, an organic aluminum compound and an activation accelerant, and the preparation method of the vanadium catalyst comprises the steps that a salicylaldehyde compound is dissolved with methyl alcohol or ethyl alcohol; and adding an organic amine compound while stirring, adding a vanadium compound after reaction, and continuously reacting to obtain the vanadium catalyst. When the prepared vanadium catalyst composition is applied to ethylene and propylene copolymerization reaction, the reactivity rate of ethylene and propylene monomers can be adjusted according to the structure of the vanadium catalyst, the C3 content of the prepared ethylene propylene rubber is 26.2-36.4 wt%, the double bond content of ethylene propylene diene monomer is adjustable in the range of 3.7-15.2 wt%, and post-processing application is facilitated.

The invention discloses a small molecular probe based on an imidazo [1, 5-a] pyridine skeleton, a preparation method and application, and belongs to the field of activatable small molecular fluorescent probes. The preparation method of the small molecular probe based on the imidazo [1, 5-a] pyridine skeleton comprises the following steps: dissolving 2-benzoylpyridine and ammonium acetate in acetic acid, adding salicylaldehyde, heating and stirring to generate a compound 3; and dissolving the compound 3 in dichloromethane, adding pyridine, stirring, adding 4-bromobutyryl chloride, and continuously stirring to obtain a compound 1, namely the small molecule probe. The small molecule probe can be used for detecting hydrazine in a biological system or drinking water.

The invention discloses preparation and application of a Salen metal complex material containing imidazolyl ionic liquid and a pyridine ring (MVIM-Salen), and belongs to the technical field of synthesis of ionic liquid metal complex catalytic materials. According to the method, salicylaldehyde containing imidazolyl ionic liquid and 2, 3-diaminopyridine are subjected to an ammonia-aldehyde condensation reaction to construct a Salen structure, a VIM-Salen complex (MVIM-Salen) material containing metal active sites is prepared through metal coordination, and the MVIM-Salen material has ionic liquid, halogen anions and metal active sites and is used for synthesizing dimethyl carbonate (DMC) through concerted catalysis of CO2. The MVIM-Salen catalytic material has the advantages of multiple active sites, uniform distribution, better stability, simple synthesis process, low synthesis cost, green and environment-friendly synthesis process and the like. The prepared MVIM-Salen catalytic material is applied to synthesis of DMC from CO2, and shows excellent catalytic performance under relatively mild reaction conditions.

The utility model relates to the technical field of chemical experiment appliances, and discloses a 3, 5-di-tert-butyl salicylaldehyde synthesizer, which comprises a base and a magnetic stirring rotor device, the top of the base is rotatably provided with a rotary clamping seat through a bearing, the top of the rotary clamping seat is provided with a clamping cavity, and the magnetic stirring rotor device is arranged in the clamping cavity. And a positioning sleeve is mounted at the top of the rotary clamping seat and is positioned on the outer side of the clamping cavity. According to the synthesis device of 3, 5-di-tert-butyl salicylaldehyde, during stirring, stirring blades rotate to push a solution close to the middle to flow and diffuse downwards and outwards, so that a solution at the top flows towards the middle, and a solution close to the inner wall of a reaction glass cup flows upwards; according to the reaction glass cup, a solution in the reaction glass cup forms a circular flow to flow, and the solution flows between the upper side and the lower side, so that the condition that solutions with different densities are layered in the stirring process can be prevented, and the stirring and mixing efficiency and the mixing effect are improved.

The invention provides an organic light-emitting material, the molecular structural formula is # imgabs0, the organic light-emitting material has the fluorescent property of coumarin, and the pi conjugated system of salicylaldehyde Schiff base is further increased, so that the organic light-emitting material has higher light-emitting efficiency. Trifluoromethyl is introduced to salicylaldehyde and aminocoumarin structures, so that the stability of the material is improved, and the material is more suitable for being used as a core material of an organic light-emitting device. The organic light-emitting material has great potential when applied to the field of organic light-emitting devices. The invention also provides a preparation method of the organic light-emitting material and an organic light-emitting device containing the organic light-emitting material.

The invention provides a dynamic continuous flow synthesis process of 5-nitrosalicylaldehyde, which comprises the following steps: filling heteropoly acid loaded on spherical activated carbon into a dynamic continuous flow reaction tube, giving a certain external temperature, adding salicylaldehyde into an organic solvent, and reacting at a certain temperature to obtain the 5-nitrosalicylaldehyde. And simultaneously pumping the 5-nitrosalicylaldehyde and nitric acid into a dynamic continuous flow reaction tube filled with a heteropolyacid immobilized catalyst at a certain flow speed, and reacting to obtain the 5-nitrosalicylaldehyde. In the process of synthesizing the 5-nitrosalicylaldehyde, the raw material concentration, the raw material flow rate, the nitric acid flow rate and the reaction temperature are strictly controlled, so that a large amount of isomer impurities are prevented from being generated, the conversion rate during nitration is favorably improved, the reaction yield is improved, the wastewater discharge is reduced, and meanwhile, the safety risk of the traditional nitration kettle type reaction is reduced. Experimental results show that the yield of the 5-nitrosalicylaldehyde is 90% or above, and the purity of the 5-nitrosalicylaldehyde is 98% or above.

Embodiments of the present application provide a method for preparing a hydroxyl ortho-hydroxymethyl-substituted methylene-bridged substituted phenol, the method comprising the following steps: A1, reacting a substituted phenol with formaldehyde in the presence of a Lewis acid catalyst to prepare a substituted salicylaldehyde compound (2); A2, condensing the substituted salicylaldehyde compound (2) in a system containing formaldehyde and a Brønsted acid catalyst to prepare a methylene-bridged substituted salicylaldehyde compound (3); A3, reducing the methylene-bridged substituted salicylaldehyde compound (3) to prepare a hydroxyl ortho-hydroxymethyl-substituted methylene-bridged substituted phenol (4). Embodiments of the present application can improve the yield and chemical purity of the prepared hydroxyl ortho-hydroxymethyl-substituted methylene-bridged substituted phenol. According to other embodiments of the present application, a method for preparing a polyphenol compound containing multiple phenol units is also provided.

Based on the excellent magnetism, synthetic difficulty and existing scarcity of asymmetric dinuclear dysprosium single-molecule magnets, a class of asymmetric dinuclear dysprosium single-molecule magnets based on bis-acylhydrazone ligands, their synthesis methods and relaxation behaviors are disclosed. Such magnets are prepared by solvothermal reaction of bis(halogen-substituted salicylaldehyde) -2,6-azoxypyridine dicarboxylic acid hydrazone ligand, dysprosium nitrate and triethylamine in a methanol-acetonitrile mixed solvent. Their common structural feature is that the acylhydrazone pockets on both wings of the ligand chelate one Dy<supgt;III< / supgt; ion respectively, and due to the difference in the ligand coordination sites of counter ions and solvent molecules, the coordination geometries of the two Dy<supgt;III< / supgt> ions in the magnet are different, showing a rare asymmetric dinuclear structure based on symmetry bipolar ligands. The alternating current susceptibility of such asymmetric dinuclear dysprosium magnets exhibits frequency-dependent magnetic relaxation phenomena even in zero field, and turns into a double relaxation process under an external magnetic field, possessing the typical characteristics of single-molecule magnets.