Spectroscopic evaluation of novel flurophores based on benzazoles

Kemijski senzori su uređaji koji pretvaraju kemijsku informaciju u analitički koristan signal. U novije vrijeme kemijski senzori sve više privlače pozornost znanstvenika zbog njihove široke primjene u medicine, biologiji i biokemiji. Glavni razlog tome je njihova osjetljivost, imunost na elektromagnetne smetnje, sigurnost prilikom rada i niska cijena. Cilj ovog rada je bio ispitati spektroskopska svojstva novih fluorofora koji se baziraju na benzazolima. Benzimidazoli su heterociklički spojevi aromatskog karaktera s imidazolnim prstenom kondenziranom na benzensku jezgru. Derivati benzimidazola pokazuju zanimljiva spektroskopska svojstva, osjetljivi su na promjenu pH zbog postojanja dušika koji se može protonirati, te mogu koordinirati metalne katione zbog prisutnosti dušika. 1,2,3-triazol je sve češća funkcionalna jedinica u optičkim senzorima jer, osim kao poveznica u konjugiranim π-sustavima, može imati ulogu u koordinaciji metalnih iona. U okviru ovog rada, sintetiziran je novi derivat benzimidazola koji sadrži 1,2,3-triazolni prsten, 2-(4-(p-tolil)-1H-1,2,3-triazol-1-il)-1H-benzo[d]imidazol, cikloadicijskom reakcijom iz odgovarajućih azida i alkina u prisutnosti Cu(I) kao katalizatora. Struktura spoja potvrđena je 1H i 13C NMR spektroskopijom, a UV-vidljivom apsorpcijskom i fluorescencijskom spektrofotometrijom ispitana su svojstva spoja u različitim otapalima i univerzalnim puferima u rasponu pH 2-12.Chemical sensors are devices that convert chemical information into an analytically useful sig-nal. More recently, chemical sensors are increasingly attracted to scientists because of their wide application in medicine, biology and biochemistry. The main reason for this is their sen-sitivity, immunity to electromagnetic interference, safety at work and low price. The aim of this paper was to examine the spectroscopic properties of new benzazole based fluorophors. Benzimidazoles are heterocyclic aromatic compounds with imidazole condensed to benzene ring. Benzimidazole derivatives exhibit interesting spectroscopic properties, sensitivity to pH change due to the presence of protonated nitrogen atom, and are sensitive to metal cations due to the presence of two nitrogen atoms. 1,2,3-triazoles became common functional moiety in optical sensors, due to their ability to act as linker in conjugated π-systems and to coordinate metal ions. In this work, new benzimidazole derivative with 1,2,3-triazole ring was synthetized, 2-(4-(p-tolil)-1H-1,2,3-triazol-1-il)-1H-benzo[d]imidazole, by cycloaddition reaction from corresponding azide and alkyne using Cu(I) as catalyst. The structure was determined by means of 1H i 13C NMR, while UV-visible absorption and fluorescence spectroscopy was used to examine the changes of its spectroscopic properties in different solvents and in universal buffer solutions in pH range 2-12