| D-A molecules are a kind of functional molecules combined electron donor with acceptor under the valence bond and weak force between molecules.Due to conjugate effects and good electron mobility within the molecular, D-A molecular systems have a relatively wide range of applications in nonlinear optics, photovoltaic conversion, Dye-sensitized solar cell, photochromic materials and other fields. In recent years, the construction of D-A molecule type photochromic materials become one of the hotspots of inorganic materials chemistry.In this paper, building crystalline materials with D-A structure is the research object,electron-deficient nitrogen heterocyclic TPT(2, 4, 6- tris(4-pyridyl)-1, 3, 5-triazine) as electron acceptor and ligand, inorganic nitrate, perchlorate, chlorine atom and inorganic phosphate as an electron donor, Zn2+ as metal connection center, series D-A molecular systems are designed and synthesized, and its structure, photochromic properties,thermostability and other aspects of the nature were characterized, analyzed and summarized.By studying the different configurations of D-A molecular systems with different photochromism,to summarize the synthesis pathways of new D-A tye photochromic crystalline materials.The main results of this thesis work are as follows:1.A photochromic compound(H3TPT)(NO3)3(compound 1)and a non-photosensitive compound(H3TPT)?(Cl O4)3?2H2O(compound 2) was synthesized with electron-deficient nitrogen heterocyclic TPT as acceptor and inorganic nitrate or perchlorate as donor.Compound 1 and compound 2 are made up of combinations of D-A blocks and are ionic supramolecular compounds., under light exposure conditions, yellow compound 1 turns to green, while compound 2 has no color change and are non-photosensitive. Both compound 1and compound 2 have a good thermostability,the frame structure of compound 1 can keep stable to 230 ℃ while compound 2 can keep stable to 350 ℃ after removing lattice water.2. A organic-inorganic hybrid compound [(H3TPT)][Zn Cl4]?Cl?4H2O(compound 3) with D-A type is synthesized,nitrogen heterocyclic TPT as acceptor and ligand,chloride as donor.Photosensitive test results show that compound 3 has no photochromic property.Structural analysis shows that its distance between the donor and acceptor motif is fartherthan the threshold range of photoinduced electron transfer reactions. The structure of compound 3 contains four lattice water molecules,and its thermostability is relatively poor,TG analysis shows its frame structure collapses with loss of lattice water.3.Four photochromic compounds with D-A type are synthesized by hydrothermal reaction, [Zn(HTPT)?(H2PO4)3](compound 4),compound 5,compound 6,compound 7,nitrogen heterocyclic TPT as acceptor and ligand and different inorganic phosphate as precursors and donors. The four compounds shown different photochromism under light irradiation:yellow compound 4 turns to red,yellow 5 turns to green, yellow 6 turns to black, and light yellow 7turns to blue. All the four compounds are organic-inorganic hybrid materials based on phosphate,by infrared spectroscopy,it shows that every compound has inorganic phosphate characteristic absorption peak and TPT block.Thermogravimetric analysis shows compound 4has a good thermostability, its frame structure can keep stable to 280℃.The powder XRD of compound 4 also displays that its frame structure keeps stable to this temperature after calcination at 280℃.Meanwhile, the decomposition temperature of compound 5,6,7 is130℃,80℃,300℃respectively. |
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