title: Solvatochromic analysis of some N-nitroso oxime derivatives--Taft and Catalan approach.
abstract: Some novel N-nitroso oxime derivatives were synthesized and characterized by (1)H, (13)C, (1)H-(1)H and (1)H-(13)C COSY NMR spectra. The spectra of all these N-nitroso oximes reveal the presence of two isomers labelled as E (-NOH group is anti to N-N=O moiety) and Z (-NOH group is syn to N-N=O moiety) in solution and the coupling constants ruled out the possibility of normal chair conformation. From the theoretical studies and coupling constant values it was found that both E (major) and Z (minor) isomers of N-nitroso oximes exist as an equilibrium mixture of CA and boat conformation (B(1)) and this was also supported by DFT calculation. The photophysical properties of these oxime derivatives were studied and the observed lower fluorescence quantum yield may be due to an increase in the non-radiative deactivation rate constant. This is attributed due to the presence of non-chair conformation of N-nitroso oxime derivatives.
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamil Nadu, India. jtchalam2005@yahoo.co.in
authors.forename: Jayaraman
authors.initials: J
authors.lastname: Jayabharathi
authors.forename: Venugopal
authors.initials: V
authors.lastname: Thanikachalam
authors.forename: Manoharan
authors.initials: M
authors.lastname: Padmavathy
authors.forename: Marimuthu Venkatesh
authors.initials: MV
authors.lastname: Perumal
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008958:Models, Molecular; D008968:Molecular Conformation; D009603:Nitroso Compounds / Q000737:chemistry*; D010091:Oximes / Q000737:chemistry*; D055668:Photochemical Processes; D012996:Solutions; D012997:Solvents / Q000737:chemistry / Q000494:pharmacology; D013237:Stereoisomerism
chemical_list: D009603:Nitroso Compounds; D010091:Oximes; D012996:Solutions; D012997:Solvents