Synthesis and fluorescence and electrochemical properties of D–π-A structural isomers of benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type and benzofuro[2,3-c]oxazolo[5,4-a]carbazole-type fluorescent dyes
exhibited significant fluorescence solvatochromic properties, compared to 2e, 2f, 3e and 3f without an electron-withdrawing substituent. The fluorescence solvatochromism of the fluorescentdyes were analyzed with the Lippert–Mataga correlation. Moreover, to elucidate the differences of photophysical properties among the fluorescentdyes, we have performed time-resolved fluorescence spectroscopic measurements
杂多环供体–π-受体(D–π-A)的结构异构体 苯并呋喃[2,3- c ]恶唑[4,5- a ]咔唑类型(2a–f)和苯并呋喃[2,3- c ]恶唑[5,4- a ]咔唑型荧光染料(3a–f),其位置不同氧 和氮原子 恶唑已经合成了环,并且已经研究了它们的光物理和电化学性质。荧光染料2a–f显示出比3a–f更强的分子内电荷转移(ICT)吸收和荧光带。两个D–π-A结构异构体显示荧光带发生红移,并且随着溶剂极性的增加,荧光量子产率降低(即正向荧光溶剂变色),3a–f的红移比2a–f的红移大。荧光染料2a–c和3a–c,具有氰基和羧基与不具有吸电子取代基的2e,2f,3e和3f相比,作为基团和作为吸电子取代基的羧酸酯表现出显着的荧光溶剂变色性质。使用Lippert-Mataga相关性分析了荧光染料的荧光溶剂合变色。此外,为了阐明荧光染料之间光物理性质的差异,我们进行了时间分辨荧光光谱测量,并通
Mechanofluorochromism of a Series of Benzofuro[2,3-<i>c</i>]oxazolo[4,5-<i>a</i>]carbazole-Type Fluorescent Dyes
Mechanofluorochromism is found for a series of benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type fluorophores (1a–1d) having cyano groups as acceptor: grinding of 1a–1d induces a fluorescent color change with an enhanced quantum yield, and the fluorescent color is recovered by heating or exposure to solvent vapor. Interestingly, both absorption and emission peaks are redshifted by grinding, in conflict