Novel heteroaromatic chromophores in optical chemical systems

Cilj ovog rada je sinteza i optička karakterizacija novih derivata benzimidazola, koji u svojoj strukturi sadrže 1,2,3-triazolni prsten i imino skupinu, u svrhu određivanja njihove senzorske aktivnosti. Imino derivati, Schiffove baze 3, 8 i 10 su uspješno pripravljeni reakcijama klasične sintetske kemije te su njihove strukture potvrđene 1H-NMR i 13C-NMR spektroskopijom. Navedeni spojevi su korišteni kao polazne molekule za sintezu triazolnih derivata 6 i 11 metodama click kemije. Spoj 6 je uspješno pripravljen, no postupak priprave spoja je potrebno poboljšati zbog vrlo malog iskorištenja reakcije. Produkt click reakcije za pripravu spoja 11 je zeleni praškasti spoj, netopiv u organskim otapalima zbog čega su njegovo pročišćavanje i karakterizacija bili otežani. Detaljna karakterizacija fotofizičkih i kiselo-baznih svojstava u svrhu ispitivanja potencijalne primjene u optičkim kemijskim senzorima je provedena za spojeve 8 i 10. Spojevi su okarakterizirani UV-vidljivom i fluorescencijskom spektrofotometrijom u otapalima različite polarnosti, u univerzalnim puferima pri graničnim pH vrijednostima od 2, 7 i 12 te u prisustvu različitih metalnih iona. Spojevi 6 i 11 nisu karakterterizirani u smislu razvoja novih optičkih senzorskih molekula zbog izrazito slabe topivosti spojeva u većini otapala te nemogućnosti izoliranja potpuno čistog produkta iz reakcijske smjese. Dobiveni rezultati, pogotovo promjene intenziteta apsorpcijskih maksimuma, ukazuju da bi bilo korisno provesti daljnja istraživanja u karakterizaciji spojeva 8 i 10 kao pH senzora. Spoj 8 pokazao je jaku senzorsku aktivnost za Zn2+ i Pb2+ dok je ispitivani spoj 10 pokazao jaku senzorsku aktivnost za Zn2+.The aim of this thesis was synthesis and optical characterization of novel benzimidazole derivates which incorporate 1,2,3-triazole ring and imine gruop in their structure, to prove their sensoring activity. Imino derivates, Schiff's bases 3, 8 and 10 are successfully prepared by classical synthetic chemistry reactions and their structures are confirmed by 1H-NMR and 13C-NMR spectroscopy.These compounds were used as starting molecules for the synthesis of triazole derivatives 6 and 11 by the click chemistry methods. Compound 6 has been successfully prepared but the process of preparing the compound need to be improved due to the low utilization of the reaction. The click reaction product of the synthesis of compound 11 is a green powder, insoluble in organic solvent which are due to its purification and characterization were difficult. Detailed characterization of photophysical and acid-base properties of compounds 8 and 10 was carried out for the purpose of testing the potential application in optical chemical sensors. Compounds was characterized with UV-visible and fluorescence spectrophotometry in solvents of different polarity, universal buffers in marginal values of pH (2, 7 and 12) and in presence of different metal ions. Compounds 6 and 11 have not been characterized in terms of the development of new optical sensor molecules due to their extremely poor solubility in most solvents and the inability to isolate the completely pure product from the reaction mixture. The obtained results, particularly changes in the absorption peak intensity, indicate that it would be useful to conduct further research into the characterization of compounds 8 and 10 as a pH sensor. Compound 8 showed strong sensory activity for Zn2+ and Pb2+ while test compound 10 showed strong sensory activity for Zn2+