Syntheses Of Novel Hybrid Organic-inorganic Photochromic Crystalline Materials Via Structural Design

Photochromism is designating for a material, which turns dark when exposed to lightand returns to its normal color with the removal of the light source. Photochromic materialshave been used in the production of optical data storage, solar cell, display devices etc.However, some defects, such as thermal instability, lacking of color control, have restrictedtheir widely applications.In this thesis, metal-based photochromic materials are constructed via introducing metalions to the organic photochromic components. Novel stable photochromic crystallinematerials based on hybrid organic-inorganic complexes have been constructed via metalcoordination and framework structure. The investigations include correlation betweenwavelength control, stability and packing arrangements, coordination modes. Related electrontransfer mechanism and chemical principles can be obtained via the characterizations ofstructures and photochromic characters. The main research results are listed as follows:Initially, a novel example of photochromic complex framework Zn(PYPDB)21isobtained with HCPBPY as started materials. PXRD and NMR data show that HCPBPYmolecule changes to PYPDB ligand through in-situ selective hydrogenation reaction withoutany precious metals as catalyst. hydrogenation mechanism is investigated by the D-substitutedreactions. Compound1is proved to be the first highly stable pyperidine photochromiccomplex with inner molecular electron transfer mechanism.Secondly, another photochromic supermolecule compound [H3tpt]·[btec]2·1.5H2O2isconstructed with TPT and H4btec as connected units. The electron acceptor molecule TPT anddonor ligand btec are connected by stacking force. Electron transfer bridges are built via aclose packing mode. A new photochromic complex with yellow to red characters is obtaineddue to the short D-A distance.Thirdly, the other novel hybrid organic-inorganic photochromic phosphate materialZn9(TPT)3(PO4)6(H3PO3)4·6H2O3is synthesized with TPT and H3PO3as started materials.Single crystal data show that it contains a3D porous structure with six-membered rings. ESR,UV-vis spectra and series of optical characterizations are used to characterize itsphotochromic property. It is a new crystalline material showing the change from yellow toblue upon light irradiation. The connection of the coordination framework short the D-Adistances, which benefit for the activation of a electron transfer process.