D.V. Semenok, J.J. Medvedev, M.S. Avdontceva, S.I. Selivanov, J. Sieler, A.S. Mereshchenko, V.A. Nikolaev
“Experimental Evidence of Intramolecular CAr–H···O=C Hydrogen Bonds in the Structure of (Diaryl)tetrahydrofuranones Using Spectroscopic Tools”
Helvetica Chim. Acta, 2016, 99, 716-723
The occurrence of bifurcate H-bonds CAr–H···O=C in the structure of (diaryl)-tetrahydrofuranones was experimentally demonstrated using different methods and techniques. The consistent increasing spin–spin coupling constants 1J(C,H) of the ortho-H-atoms and low-field shift of v (C=O) in IR spectra of 2,2-(diaryl)tetrahydrofuran-3(2H)-ones relative to their 5,5-diaryl counterparts, as well as pronounced dependence of the ortho-C–H H-atoms chemical shifts on the temperature and solvent polarity along with X-ray diffraction analysis data unambiguously point to the existence of weak CAr–H···O=C H-bonds in these molecules.