1‐Oxo‐1,3‐dithiolane (4) and its cis‐ and trans‐2‐methyl (5,6), ‐4‐methyl (7,8) and ‐5‐methyl (9,10) derivatives were prepared by oxidizing the corresponding 1,3‐dithiolanes (1–3) with NaIO4 in water. The oxides were purified and their isomers separated using thin layer chromatography. The structural characterization was carried out with 1H and 13C NMR spectroscopy and molecular modelling. The sulfoxides
An NMR study of the fluxionality of group VI metal pentacarbonyl complexes of 1,3-dithiolanes
作者:Edward W. Abel、Keith G. Orrell、Khurshid B. Qureshi、Vladimir Šik
DOI:10.1016/s0277-5387(00)80279-x
日期:1990.1
The complexes [M(CO)5(RR′)] (M = Cr, Mo or W, R = R′= H; M = Cr or W, R = R′= Me, R = H, R′= Me, But or Ph) have been synthesized and characterized. Their solution stereodynamics were examined by 1H NMR spectroscopy. Pyramidal inversion of the metal-coordinated sulphur atoms occurs rapidly at ambient temperatures (ΔG‡ (298 K) = 40–44 kJ mol−1). An appreciably slower 1,3-metal—sulphur shift is also