Strukturne i solvatohromne karakteristike 5-(arilazo)-3-cijano-6-hidroksi-4metil-1-supstituisanih-2-piridona

Abstract

U okviru disertacije, sintetisane su tri serije arilazo piridonskih boja: 5-(arilazo)- 3-cijano-1-etil-6-hidroksi-4-metil-2-piridoni, 5-(arilazo)-3-cijano-6-hidroksi-4-metil-2- -piridoni i 5-(4-arilazo)-3-cijano-6-hidroksi-1-hidroksietil-4-metil-2-piridoni. Predmet istraživanja je potpuna strukturna i solvatohromna karakterizacija sintetisanih jedinjenja kombinacijom eksperimentalnih tehnika i kvantno-hemijskih proračuna. Eksperimentalne metode podrazumevaju rendgensku strukturnu analizu i FT-IR, NMR i UV-Vis spektoskopiju. Energija, geometrijske strukture i vibracioni talasni brojevi 5-(metoksi supstituisanih fenilazo)-3-cijano-1-etil-6-hidroksi-4-metil-2-piridona dobijeni su kvantno-hemijskim proračunom, korišćenjem B3LYP, M06 i M06-2X modela, a stabilnost ovih molekula, kao posledica hiperkonjugativnih interakcija i delokalizacije naelektrisanja, izučavana je pomoću NBO analize. Optimizovane geometrije 5-(arilazo)- -3-cijano-1-etil-6-hidroksi-4-metil-2-piridona u vakuumu dobijene su pomoću B3LYP/6-311++G(d,p) metode. UV-Vis apsorpcione energije za ista jedinjenja dobijene su pomoću vremenski zavisne DFT metode (TD-DFT). Simulacija je izvedena pomoću četiri modela: B3LYP, CAM-B3LYP, M06-2X i PBE0. UV-Vis spektralna svojstva jedinjenja i tautomerija detaljno su ispitani u dva rastvarača i to u etanolu i N,N-dimetilformamidu. Analizirani su UV-Vis apsorpcioni spektri u različitim rastvaračima i ispitivan je njihov uticaj na položaj apsorpcionih maksimuma. Takođe, ispitivan je uticaj prirode i položaja supstituenata u fenilnom jezgru i različitih supstituenata u položaju 1 piridonovog jezgra na apsorpcione spektre. Za kvantitativnu ocenu uticaja rastvarača na apsorpcione maksimume svih jedinjenja, primenjeni su principi LSER analize, i to Kamlet-Taft-ov i Catalán-ov model. Kvantitativna analiza uticaja supstituenata na apsorpcione maksimume 5-(4-arilazo)-3- -cijano-6-hidroksi-1-hidroksietil-4-metil-2-piridona urađena je pomoću LFER modela i to primenom Hammett-ove jednačine. Pored toga, LFER model je primenjen i u ispitivanju uticaja elektronskih efekata supstituenata na 1H and 13C NMR pomeraje,...

In this thesis, three series of arylazo pyridone dyes 5-(substituted phenylazo)-3- -cyano-1-ethyl-6-hydroxy-4-methyl-2-pyridones, 5-(substituted phenylazo)-3-cyano-6- hydroxy-4-methyl-2-pyridone and 5-(4-substituted phenylazo)-3-cyano-6-hydroxy-1- -hydroxyethyl-4-methyl-2-pyridone have been synthesized. The purpose of this research is a combined experimental and theoretical characterization of the synthesised dyes. Experimental methods include X-ray single-crystal analysis, as well as FT-IR, NMR and UV-Vis spectroscopy. Quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of 5-(methoxy substituted phenylazo)-3-cyano-1-ethyl-6- -hydroxy-4-methyl-2-pyridones have been performed using B3LYP, M06 i M06-2X models. Stability of these molecules arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital analysis. Optimized geometries in vacuum for 5-(substituted phenylazo)-3-cyano-1-ethyl-6-hydroxy-4- -methyl-2-pyridones have been obtained using B3LYP/6-311++G(d,p) model. UV-Vis apsorbtion energies have been calculated using TD-DFT using B3LYP, CAM-B3LYP, M06-2X and PBE0 models. UV-Vis spectral properties and tautomerism have been throughly investigated in ethanol and N,N-dimethylformamide. The effects of the nature and the position of the substituents in phenyl ring on UV-Vis spectra in different solvents have been examined, as well as the impact of different substituents in the position 1 of pyridone ring. Furthermore, solvent effects on absorption spectra have been analysed. For quantitative evaluation of the solvent effects on the UV-Vis absorption maxima, the principles of the linear solvation energy relationships are used, i.e. models proposed by Kamlet–Taft and Catalán. Linear free energy relationships are applied to the UV-Vis absorption spectra and correlation of absorption frequencies with Hammett substituent constants are performed. Furthermore, the influence of the electronic nature of the substituents on 1H...