Synthesis And Supramolecular Chemistry Of Nitrogen- And Sulfur-Containing Heterocyclic Compounds

Supramolecular chemistry is a new and promising subject. A study on the synthesis and supramolecular chemistry of several nitrogen- and sulfur-containing heterocyclic compounds was carried out in this dissertation. The main results are summarized as follows:1. Six nitrogen- and sulfur- containing heterocyclic compounds were synthesized with amine and carbon disulfide by solvothermal reactions, which providing a simple and effective approach to the synthesis of nitrogen- and sulfur- containing heterocyclic compounds.2. A polyheterocyclic hypervalent molecule with N-S-N hypervalent bond , 2-(2-Pyridylimino)-2H-l,2,4-thiadiazolo[2,3-a]pyridine(PTP), was selected to research the effects of protonation, metal-coordination bond and hydrogen bond at imino nitrogen atoms on the strength of N-S-N hypervalent bond. The formation of coordination bond and hydrogen bond at N3 atom in PTP causes the electron-withdrawing ability of the N4 side increase relative to the N1 side. Therefore the S1-N4 bond is elongated and attractive interaction in the N4 side is weakened. In contrast, the S1-N1 attractive interaction of the Nl side is strengthened. The influence of the effects investigated is in the following order: protonation > metal-coordination bond > hydrogen bond.3. With hypervalent molecule PTP as 1,3-bifunctional bidentate ligand, and various carboxylate ancillary ligands, four dinuclear silver(I) complexes were synthesized. X-ray structural analysis shows that PTP can act as a potential 1,3-bifunctional bidentate ligand for spanning short metal-metal interactionsHIbetween Ag(I) ions. The four complexes contain short Ag-Ag separations between 2.8191(14) A and 2.8798(9) A bridged by the ligand. All these complexes show strong blue luminescences at room temperature, which were assigned to silver-perturbed intraligand fluorescence.4. The polymorphism, photochromism and anion recognition properties of 7-amino-4-hydroxy-lH-quinazoline-2-thione(AHQT), a quinazoline derivative, were investigated. AHQT has two polymorphs with different absorption and fluorescence spectra. The UV, fluorescence and 1H NMR analysis of the photochemistry of AHQT showed that the photochromic phenomenon was due to the photoisomerization from enol form to keto form. The photocolored product of AHQT was found to undergo sensitive response to H2PO4 anion in acetonitrile. The response was assumed to result from the formation of 1:1 hydrogen-bonded complex.