Hydrogen bonds in phenylboronic acids with polyoxaalkyl substituents at ortho-position
作者:Agnieszka Adamczyk-Woźniak、Michał K. Cyrański、Aldona Dąbrowska、Błażej Gierczyk、Paulina Klimentowska、Grzegorz Schroeder、Anna Żubrowska、Andrzej Sporzyński
DOI:10.1016/j.molstruc.2008.12.006
日期:2009.2
Phenylboronic acids with polyoxaalkyl substituents at ortho position were synthesized from the corresponding bromides. Structures in solid state, determined by single crystal X-ray diffraction, reveal the presence of inter- and intramolecular hydrogen bonds. Presence of several oxygen atoms in oxaalkyl chains enables the formation of intramolecular hydrogen bonds by B(OH)(2) group with different oxygen centers which lead to the formation of bifurcated hydrogen bonds. Investigated compounds were characterized by H-1, C-13, B-11 and O-17 NMR spectroscopy in solution. Assignment of H-1 and C-13 signals was made on the basis of HSQC and HMBC spectra. O-17 NMR spectra show that in acetonitrile solution hydrogen bonds with solvent molecules are predominant. (C) 2008 Elsevier B.V. All rights reserved.