1186127-92-3Relevant articles and documents
4-Substituted 1-acyloxypyridine-2(1H)-thiones: Experimental and computational studies of the substituent effect on electronic absorption spectra
Jankowiak, Aleksandra,Kaszynski, Piotr
, p. 7441 - 7448 (2009)
(Chemical Equation Presented) A series of eight 4-substituted 1-(adamantane-1-carbonyloxy)pyridine-2(1H)-thiones (1, X=H, OC7H 15, Me, CF3, SC3H7, CN, COOMe, and Cl) was prepared and characterized by UV-vis spectroscopy in MeCN and cyclohexane. The observed lowest energy transition, designated as πCS→ π*ring, exhibits a substantial substituent effect and λmax ranges from 333 (X=OC 7H15) to 415 nm (X=CN). Experimental λ max values for all esters except for 1b (X=OC7H 15) correlate with the σp - parameter (ρ = 0.41 ± 0.03, r2= 0.95). In contrast, the energy of the absorption band at about 295 nm, designated as πCS → π*CS, is practically substituent independent. Both absorption bands exhibit a modest negative solvatochromic effect. The experimental absorption energies correlate better with excitation energies calculated for N-acetyloxy analogues 2 with the ZINDO//DFT than with the TD-DFT//DFT method. Calculations for a series of 12 N-acetates 2 predict the most blueshifted π → π* transition for the alkoxy substituent and most red-shifted for the NO2 group relative to the parent 2a (X = H). 2009 American Chemical Society.
