| In recent years, polypyridine compounds charactered by conjugate π-electron structure and the luminescent complexes formed by polypyridine ligands with transition metal have gained a lot of attention for their applied potential as the sensor materials, probes and optical materials. Amid these above-mentioned, compounds of 1,8-naphthyridine derivant have been attracting more and more attention for their abundant properties and much applied potential in the material and biology fields. In this paper, a series of luminescent compounds based on 1,8-naphthyridine unit were designed and synthesized. We study their coordinated abilities in order to modify and choose better ligands. Moreover, the photochemical and photophysical properties, functional group properties and sensitive properties of these compounds were investigated by spectra of UV-Vis, spectra of emission and spectra of excitation. The main works are as follows:1,We designed and synthesized three new styryl-1,8-naphthyridine compounds, 7-Amino-4-methyl-2-styryl-1,8-naphthyridine, 7-Amino-4-methyl-2-(p-hydroxyl) styryl-1,8-naphthyridine and 7-Amino-4-methyl-2-(p-nitro)styryl-1,8-naphthyridine. Among these compounds, the structure of 7-Amino-4-methyl-2-styryl-1,8- naphthyridine has been proved by the measurement methods of IR , UV , MS , 1H NMR and so on . And the structure investigation of 7-Amino-4-methyl-2-(p- hydroxyl)styryl- 1,8-naphthyridine has also been performed. Otherwise, the first purification of 7-Amino-4-methyl-2-(p-nitro)styryl-1,8-naphthyridine has been finished. 2,We synthesized some compounds of 1,8-naphthyridine derivant with other functional group. The other polypyridine compounds with -OH,-COOH , 1,8-naphthyridine, 2-Amino-7-hydroxy-1,8-naphthyridine, 7-Amino-2,4-dimethyl-1,8-naphthyridine, 1,8-naphthyridine-2,4-dicarboxylicacid, 2,2'-bipyridyl-3,3'- bicarboxylic acid and 1,10-phenanthroline-2,9-bimethylene-imion-(2,2'-bimethyl) biacetic acid have been synthesized. After primary purification finished we studied the coordinated abilities of above ligands by coordination with [Cu(CH3CN)4]BF4 or CuI or Zn(OAc)2. The compound, 7-Amino-2,4-dimethyl- 1,8-naphthyridine, has been encapsulated in mesoporous molecular sieve MCM-41, and 2,2'-bipyridyl-3,3'-bicarboxylic acid has been attached to TiO2 nanomaterial. We found that compound 2-Amino-7-hydroxy-1,8-naphthyridine shows a sensitive response to CH2Cl2 and CH3CN. Add few CH2Cl2 or CH3CN into this compound, the luminescence of this solid changed from yellow to blue after solvent volatilized. Upon exposure of this solid to the vapor or in contact with the liquid phase of volatile organic compounds, such as CH3OH , CH3CH2OH , the variance was not observed. The hydrogen bond is the main reason to this sensitive property. The structure study of compound 2-Amino-7-hydroxy-1,8-naphthyridine implies a intermolecular hydrogen bond is formed , addition of CH2Cl2 or CH3CN destroyed hydrogen bond and made it change into monomer form. Its luminescence changed, too. Adding CH3OH or CH3CH2OH, we didn't find this variance because they are protonic solvent and have not influence to hydrogen bond.3,The styryl-1,8-naphthyridine compounds, 7-Amino-4-methyl-2-styryl-1,8- naphthyridine and 7-Amino-4-methyl-2-(p-hydroxyl)styryl-1,8-naphthyridine, have good pH sensitive properties. Their absorption spectra, emission spectra and excited spectra are all changed by environmental PH value. The former has good sensitivity to acid, which come from protonation of compound. The latter has good sensitivity to acid and alkali, which come from protonation of compound and dissociation of hydroxyl in benzene ring. These compounds are consided as conjugate structures, electron donors and electron acceptors. Furthermore, these compounds have not photoisomerization probability for their large charge density focused on 1,8-naphthyridine ring, so that they have better emission quantum yields. Above characters show their applied potential as luminescent pH probes....
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