화학공학소재연구정보센터
Inorganic Chemistry, Vol.47, No.5, 1502-1511, 2008
Functionalized tellurols: Synthesis, spectroscopic characterization by photoelectron spectroscopy, and quantum chemical study
Ethene-, cyclopropane-, 3-butene-, and cyclopropanemethanetellurol have been synthesized by reaction of tributyltin hydride with the corresponding ditellurides and characterized by H-1, C-13, and Te-125 NMR spectroscopy and high-resolution mass spectrometry. The tellurols of this series, with a gradually increasing distance between the tellurium atom and the unsaturated group, have been studied by photoelectron spectroscopy and quantum chemical calculations. Two stable conformations of ethenetellurol and cyclopropanetellurol, five of allyltellurol, and four of cyclopropanemethanetellurol were found. In the photoelectron spectrum of vinyltellurol, the huge split between the first two bands indicates a direct interaction between the tellurium lone electron pair and the double bond. In the allyl derivative, a hyperconjugation effect was found for the most stable conformers. In contrast to the vinyl compounds, no direct interaction between the lone electron pair of X (X = O, S, Se, and Te) and the three-membered ring could be observed in the cyclopropyl derivatives. A hyperconjugation-like effect, which is independent of the relative orientation of the X-H group, is found to increase from S to Te. Thus, the type and extent of the. interaction between the TeH group and an unsaturated or cyclopropyl moiety are clarified while the first comparison of interactions between the nonradioactive unsaturated chalcogen derivatives is performed.