Sinteza i spektroskopska karakterizacija novih akrilonitrilnih derivata benzoksazola kao potencijalnih senzora za pH u otopinama

undergraduate thesis

• Title (english): Synthesis and spectroscopic characterization of novel acrylonitrile benzoxazole derivatives as potential sensors for pH in solutions
• Author: Martin Keleminić
• Mentor: Marijana Hranjec (mentor)
• Committee member: Marijana Hranjec (predsjednik povjerenstva)
• Committee member: Ivana Sokol (član povjerenstva)
• Committee member: Kristina Tolić Čop (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-09-11, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U ovom radu provedena je sinteza novih akrilonitrilnih derivata benzoksazola. Nadalje, sintetizirani derivati 10-13 spektroskopski su okarakterizirani kako bi se utvrdila mogućnost njihove primjene kao potencijalnih optičkih pH senzora u otopinama. Sinteza spojeva 10-13 provedena je uobičajenim reakcijama organske kemije temeljenih na načelima zelene kemije, te reakcijom potpomognutom mikrovalovima. Aktivacijom malonitrila 1 uz TMSCl
(trimetilsilil-klorid) 2 i etanol, priređen je etil-2-cijano-acetamidat-hidroklorid 3. Glavni prekursor, tj. 2-cijanometilbenzoksazol 5 sintetiziran je reakcijom 2-aminofenola 4 i spoja 3 korištenjem dviju različitih metoda, u talini i reakcijom potpomognutom mikrovalovima. Ciljani akrilonitrilni derivati benzoksazola 10-13 dobiveni su Knoevenagelovom reakcijom, između
2-cijanometilbenzoksazola 5 i odgovarajućih benzaldehida 6-9 u vodi kao otapalu i uz korištenje K2CO3 u reaktoru za paralelnu sintezu. Sintetizirani spojevi 10-13 okarakterizirani su UV/Vis spektroskopijom u sedam organskih otapala različitih polarnosti, te UV/Vis pH titracijama u otopinama pufera različitih pH vrijednosti. Strukture spojeva 10-13 potvrđene su 1H i 13C NMR spektroskopijom. Provedena ispitivanja pokazala su bitne promjene spektroskopskih svojstava spojeva 10-13 ovisno o polarnosti otapala te promjeni pH vrijednosti, što ukazuje na moguću potencijalnu primjenu sintetiziranih spojeva kao optičkih pH senzora u otopinama.

Abstract (english)

This work represents the synthesis of novel acrylonitrile derived benzoxazoles. Onwards, synthesized derivatives 10-13 were spectroscopically characterized in order to determine their possibility for the application as potential optical pH sensors in solutions. The synthesis of compounds 10-13 was carried out by common reactions of organic chemistry based on the principles of green chemistry and by microwave assisted reaction. By activating malonitrile 1 with TMSCl (trimethylsilyl chloride) 2 and ethanol, ethyl-2-cyano-acetamidate-hydrochloride 3 was prepared. The main precursor, i.e. 2-cyanomethylbenzoxazole 5 was synthesized by the reaction of 2-aminophenol 4 and compound 3 using two different methods, reaction in melt and microwave assisted reaction. Targeted acrylonitrile derived benzoxazole 10-13 were obtained by the Knoevenagel reaction, from
2-cyanomethylbenzoxazole 5 and the corresponding benzaldehydes 6-9 in water as a solvent and using K2CO3 in a reactor for parallel synthesis. The synthesized compounds 10-13 were characterized by UV/Vis spectroscopy in seven organic solvents with different polarity, and UV/Vis pH titrations with buffered solutions of different pH values. The structures of compounds 10-13 were confirmed by 1H and 13C NMR spectroscopy. Conducted experiments showed significant changes in the spectroscopic properties of compounds 10-13 with a change of the polarity and pH values, which indicates the possible potential use of the synthesized compounds as optical pH sensors in solutions.

• Keywords: akrilonitrili; benzoksazoli; optički pH senzori; zelena kemija; UV/Vis spektroskopija; NMR spektroskopija; spektroskopska svojstva
• Keywords (english): acrylonitriles; benzoxazoles; optical pH sensors; green chemistry; UV/Vis spectroscopy; NMR spectroscopy; spectroscopic properties
• Language: croatian
• URN:NBN: urn:nbn:hr:149:832061
• Project: Number: IP-2020-02-8090; Title: Dizajn, sinteza i računalna analiza novih optičkih kemijskih pH osjetilnih derivata benzazola; Title: Design, Synthesis and Computational Analysis of Novel Optical Chemical pH Sensing Benzazole Derivatives; Acronym: BenzpHSens; Leader: Robert Vianello; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Research Projects
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-07-01
• Created on: 2024-11-12 13:50:43