Synthesis and Solvatochromic Properties of Some Novel Symmetrical and Asymmetrical Heterocyclic Disazo Dyes Based on Pyrazolo[1,5-a]Pyrimidine Derivatives

• Main Authors: Pi-Chen Tsai, 蔡弼丞
• Other Authors: Ing-Jing Wang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/49g7pn

博士 === 國立臺灣科技大學 === 高分子系 === 95 === The disertation consists of two main themes: Firstiy, (1) 3,5-Di-(amino or methyl)-4-substituted-azoly-pyrazole and 3-amino-5- methyl-4-substituted-azoly-pyrazole have been synthesized via the cyclization from hydrazine hydrate with 2-substituted-azoly-malono- nitrile, 3-sub-stituted-azoly-pentane-2,4-dione and 3-imino-2-substitu- ted-azoly-butyronitrile, respectively; and (2) 5-amino-3-methyl-4-substi -tuted-azoly-pyrazole and 3-amino-4-substituted-azoly-5-pyrazolone were prepared by coupling reaction of aniline derivatives with 3-amino-5-pyrazolone and 5-amino-3-methylpyrazole, respectively. The effect of maximum absorption spectra on synthesized pyrazole monoazo dyes with different substituents and their different locations was also evaluated by UV-ray in acetone. After a series of analyses, we can realize that the substituent effect of maximum absorption spectra on the 5th position of pyrazole ring is more dominant than the 3rd position of that. Secondly, (1) 3,6-Diphenylazo pyrazole[1,5-a]pyrimidine disazo dyes were synthesized both by the cyclization of 2-(4-substituted- phenylazo)- malononitrile with 3,5-diamino-4-(4-substituted-phenyl- azo)-pyrazole; (2) 4-(Aryl or hetaryl)azo-3,5-diaminopyrazole com- pounds with arylazo- and hetarylazo- malononitriles were prepared by the cyclization to obtain the 3,6-di-(aryl or hetaryl)- azo-2,5,7-triamino- pyrazolo[1,5-a]pyrimidine heterocyclic disazo dyes; (3) 3,6-dihetaryl- azo-2,5,7-triamino-pyrazolo[1,5-a]pyrimidine heterocyclic disazo dyes have been synthesized via the cyclization from some substituted hetarylazomalononitrile precursors with various substituted hetarylazo- pyrazole compounds. The effect of maximum absorption spectra on these prepared hetercyclic disazo dyes with and various solvents was investigated by the UV-ray test. In addition, the effect due to different substituents and polarities was also evaluated.The solvatochromic behavior of these dyes in various solvents with different dielectric constants reveals bathochromic shifts as the solvent polarity is increased. Although, the substituents can be arylazo or hetarylazo by comparing with the synthesized hetarcyclic disazo dye, we can know the different effect of maximum absorption spectrum for pyrazole- [1,5-a]pyrimidind compounds. By the related analyses, the maximum absorption spectrum of dyes may have a trend of moving to long wavelength when the substituted on the 3,6th position of pyrazole- [1,5-a]pyrimidind ring changing to hetarylazo group. All synthesized compounds in this disertation were analyzed to recognize their chemical structures through spectrum identification of FT-IR, UV, and 1H-NMR and EA.