Sinteza i spektroskopska karakterizacija akrilonitrilnih derivata N-supstituiranih benzimidazola kao potencijalnih senzora za pH u otopinama

undergraduate thesis

• Title (english): Synthesis and spectroscopic characterization of N-substituted benzimidazole acrylonitrile derivatives as potential sensors for pH in solutions
• Author: Matko Fančović
• Mentor: Marijana Hranjec (mentor)
• Committee member: Marijana Hranjec (predsjednik povjerenstva)
• Committee member: Silvija Maračić (član povjerenstva)
• Committee member: Petar Kassal (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-16, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U okviru ovog rada provedene su sinteze akrilonitrilnih derivata N-supstituiranih benzimidazola. Željeni spojevi 14-18 pripravljeni su korištenjem uobičajenih metoda organske sinteze kao i mikrovalovima potpomognutim reakcijama. 3-nitro-4-(N-fenilamino)benzonitril 2 priređen je reakcijom nukleofilne aromatske supstitucije, tj. nekataliziranom aminacijom potpomognutom mikrovalovima početnog 3-klor-4-nitrobenzonitrila 1 u acetonitrilu uz prisutnost anilina. Spojevi 3-7 priređeni su redukcijom 4-N-fenilamino-3-nitrobenzonitrila 2 u kojoj se nitro skupina prevodi u amino skupinu uz korištenje kositrovog klorida dihidrata. 2- cijanometilbenzimidazoli 8-12 priređeni su zagrijavanjem spojeva 3-7 i 2-cijanoacetamida u reakciji ciklokondenzacije na temperaturi 185 ºC. Željeni akrilonitrilni derivati benzimidazola 14-18 priređeni su reakcijom aldolne kondenzacije iz 2-cijanometilbenzimidazola 8-12 i 4-N,Ndietilaminobenzaldehida 13. Strukture svih priređenih spojeva potvrđene su 1H NMR i 13C NMR spektroskopijom, a strukture željenih akrilonitrilnih derivata benzimidazola 14-18 potvrđene su i MS spektroskopijom. Željeni spojevi 14-18 okarakterizirani su UV/Vid i emisijskom fluorimetrijskom spektroskopijom u otapalima koja se razlikuju po polarnosti: MQ voda, toluen, etanol, metanol, acetonitril i etil-acetat. Promjene spektroskopskih svojstava spojeva 14-18 ovisno o različitim pH vrijednostima otopina pufera promatrane su pH titracijama. Na taj je način ispitana mogućnost njihove primjene kao optičkih pH senzora.

Abstract (english)

This work presents synthesis of acrylonitrile derivatives of N-substituted benzimidazoles. Preferred compounds 14-18 were prepared using conventional organic synthesis methods as well as microwave-assisted reactions. 3-nitro-4-(N-phenylamino)benzonitrile 2 was prepared by a nucleophilic aromatic substitution reaction, i.e., uncatalyzed amination assisted by microwaves of the initial 3-chloro-4-nitrobenzonitrile 1 in acetonitrile in the presence of aniline. Compounds 3-7 were prepared by reduction of 4-N-phenylamino-3-nitrobenzonitrile 2 in which the nitro group was converted to the amino group using tin chloride dihydrate. 2- cyanomethylbenzimidazoles 8-12 were prepared by heating compounds 3-7 and 2- cyanoacetamide in a cyclocondensation reaction at 185 °C. The desired acrylonitrile derivatives of benzimidazole 14-18 were prepared by the reaction of aldol condensation from 2- cyanomethylbenzimidazole 8-12 and 4-N,N-diethylaminobenzaldehyde 13. The structures of all prepared compounds were confirmed by 1H NMR i 13C NMR spectroscopy, and the structures of the desired acrylonitrile derivatives of benzimidazole 14-18 were confirmed also by MS spectroscopy. Preferred compounds 14-18 were characterized by UV/Vid and emission fluorimetric spectroscopy in solvents differing in polarity: MQ water, toluene, ethanol, methanol, acetonitrile and ethyl-acetate. Changes in spectroscopic properties of compounds 14- 18 depending on different pH values of buffer solutions were observed by pH titrations. In this way, the ability to use them as optical pH sensors was investigated.

• Keywords: akrilonitrili; benzimidazoli; MW sinteza; UV/Vid i NMR spektroskopija; pH senzori
• Keywords (english): acrylonitriles; benzimidazoles; MW synthesis; UV/Vis and NMR spectroscopy; pH sensors
• Language: croatian
• URN:NBN: urn:nbn:hr:149:301190
• Project: Number: IP-2018-01-4379; Title: Istraživanje antioksidativnog djelovanja benzazolskog skeleta u dizajnu novih antitumorskih agensa; Acronym: AntioxPot; Leader: Marijana Hranjec; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• 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: HRZZ; Funding stream: IP
• 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: Access restricted to students and staff of home institution
• Created on: 2023-03-28 07:46:09