title: (13)C NMR substituent-induced chemical shifts in 4-(substituted phenyl)-3-phenyl-1,2,4-oxadiazol-5(4H)-ones (thiones).
abstract: In the present, study mostly novel ten 4-(substituted phenyl)-3-phenyl-1,2,4-oxadiazol-5(4H)-ones and ten 4-(substituted phenyl)-3-phenyl-1,2,4-oxadiazol-5(4H)-thiones were synthesized. These oxadiazole derivatives were characterized by IR, (1)H NMR, (13)C NMR and elemental analyses. Their (13)C NMR spectra were measured in Deuterochloroform (CDCl3). The correlation analysis for the substituent-induced chemical shift (SCS) with Hammett substituent constants (σ), Brown Okamoto substituent constants (σ(+), σ(-)), inductive substituent constants (σI) and different of resonance substituent constants (σR, σR(o)) were performed using SSP (single substituent parameter), DSP (dual substituent parameter) and DSP-NLR (dual substituent parameter-non-linear resonance) methods, as well as single and multiple regression analysis. Negative ρ values were found for all correlations (reverse substituent effect). The results of all statistical analyses, (13)C NMR chemical shift of CN, CO and CS carbon of oxadiazole rings have shown satisfactory correlation.
authors.affiliation: Kocaeli University, Science and Art Faculty, Department of Chemistry, Umuttepe Campus, 41380 Kocaeli, Turkey.
authors.forename: Yesim Saniye
authors.initials: YS
authors.lastname: Kara
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D017711:Nonlinear Dynamics; D013871:Thiones / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D013871:Thiones
keywords: DSP analyses; DSP-NLR analyses; Hammett correlation; Oxadiazole ring; Reverse substituent effect; SSP analyses