C-(HO)-O-... hydrogen bonds in small ring carbonyl compounds: Vibrational spectroscopy and ab initio calculations

authors	Vaz, PD; Ribeiro-Claro, PJA
nationality	International
journal	STRUCTURAL CHEMISTRY
author keywords	C-(HO)-O-... hydrogen bonds; carbonyl stretching mode; isosbestic points; blue-shifted bands
keywords	COMPLEX-FORMATION; PROPIONITRILE; IMPROPER; CRESOL
abstract	The effect of the molecular structure on the properties of C-H... 0 bonds was investigated in a set of small cyclic carbonyl compounds, using vibrational spectroscopy and ab initio calculations. Two main effects were studied: the size of the ring and the inclusion of oxygen atoms in the ring. The analysis of the band profile of the carbonyl stretching mode reveals the presence of single dimerization equilibria in the series cyclobutanone-cyclopentanone-cyclohexanone. The smallest cyclobutanone was found to have the lowest dimerization energy, with an experimental Delta H value of 3.7 +/- 0.6 kJ mol(-1). The systems with oxygen atoms in the ring, gamma-butyrolactone and ethylene carbonate were found to present more complex equilibria. Ab initio calculations suggest that this complexity is due to the presence of additional dimer structures and higher oligomers.
publisher	SPRINGER/PLENUM PUBLISHERS
issn	1040-0400
year published	2005
volume	16
issue	3
beginning page	287
ending page	293
digital object identifier (doi)	10.1007/s11224-005-4460-y
web of science category	Chemistry, Multidisciplinary; Chemistry, Physical; Crystallography
subject category	Chemistry; Crystallography
unique article identifier	WOS:000230341800012