Iminocoumarine derivatives as potential solvatochromic probes

Abstract

Svrha ovog rada jest optička karakterizacija novosintetiziranih derivata iminokumarina IM1 - IM4, s ciljem utvrđivanja njihove potencijalne primjene kao solvatokromnih proba. Određivanje utjecaja otapala na optička svojstva ispitivanih spojeva bitan je korak u daljnjoj karakterizaciji novosintetiziranih spojeva kao potencijalnih pH i metalnih (kemo)senzora u otopinama i plastificiranoj polimernoj matrici. UV-vidljivom apsorpcijska i fluorescencijska spektrofotometrijom ispitan je utjecaj strukture na spektralna svojstva derivata iminokumarina u otopinama. Proučavan je utjecaj otapala različitih parametara polarnosti na spektralna svojstva spojeva 7-N,N-dietilamino-2- imino-3-(2-N-metilbenzimidazolil)kromen (IM1), 2-imino-3-(2-Nmetilbenzimidazolil) kromen (IM2), 7-N,N-dietilamino-2-imino-3-(2-N-5-nitro-1Hbenzimidazolil) kromen (IM3) i 7-N,N-dietilamino-2-imino-3-(2-N-1Hbenzimidazolil) kromen (IM4). Spektrofotometrijskom karakterizacijom ispitivanih spojeva u različitim otapalima utvrđeno je da spektralne karakteristike spomenutih derivata iminokumarina ovise o polarnosti i vrsti otapala. Spojevi IM1, IM2 i IM4, 7-N,N-dietilamino-2-imino-3-(2-Nmetilbenzimidazolil) kromen, 2-imino-3-(2-N-metilbenzimidazolil)kromen i 7-N,Ndietilamino- 2-imino-3-(2-N-1H-benzimidazolil)kromen, uz detaljnija ispitivanja mogu biti korišteni kao solvatokromne probe. Spoj IM3, 7-N,N-dietilamino-2-imino-3-(2-N-5-nitro-1Hbenzimidazolil) kromen, pokazuje najizraženije spektralne promjene, no nije pogodan za navedenu primjenu zbog izrazito slabe topljivosti.The aim of this work was the optical characterisation of novel iminocoumarine derivatives IM1 – IM4 in order to determine their applicability as solvatochromic probes. Effect of solvent is an important parameter for the further characterisation of examined derivatives as a potential pH and metal (chemo)sensors in solutions and polymer matrices. Compunds were characterised by UV-visible absorption and fluorescence spectrophotometry in order to examine effect of solvents on the spectral properties of the tested compunds. Effect of solvent on a spectral properties has been determined for compounds 7-N, N-diethylamino-2-imino-3-(2-N-methylbenzimidazolyl) chromene (IM1), 2- imino-3-(2-N-methylbenzimidazolyl) chromene (IM2), N,N-diethyl-2-imino-3-(5-nitro-1Hbenzo[ d]imidazol-2-yl)-2H-chromen-7-amine (IM3) and 7-N, N-diethylamino-2-imino-3-(2- N-1H-6-nitrobenzimidazolyl) chromene (IM4). Spectral characteristics of mentioned iminocoumarine derivatives depend on a type and polarity of a solvent. Compounds IM1, IM2 and IM4, 7-N, N-diethylamino-2-imino-3- (2-N-methylbenzimidazolyl) chromene, 2-imino-3-(2-N-methylbenzimidazolyl) chromene and 7-N,N-diethylamino-2-imino-3-(2-N-1H-6-nitrobenzimidazolyl) chromene, can be used as a solvatochromic probes. Compound IM3, N,N-diethyl-2-imino-3-(5-nitro-1Hbenzo[ d]imidazol-2-yl)-2H-chromen-7-amine, shows the most extreme spectral changes but it is not suitable for mentioned application because of its extremely low solubility