Halogen bonded complexes between volatile anaeshetics (chloroform, halothane, enflurane, isoflurane) and formaldehyde: a theoretical study

0360674 - ÚOCHB 2012 RIV GB eng J - Journal Article
Zierkiewicz, W. - Wieczorek, R. - Hobza, Pavel - Michalska, D.
Halogen bonded complexes between volatile anaeshetics (chloroform, halothane, enflurane, isoflurane) and formaldehyde: a theoretical study.
Physical Chemistry Chemical Physics. Roč. 13, č. 11 (2011), s. 5105-5113. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA MŠMT LC512
Institutional research plan: CEZ:AV0Z40550506
Keywords : halogen bond * anaesthetics * ab initio calculation
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.573, year: 2011

The structures and intermolecular interactions in the halogen bonded complexes of anaesthetics (chloroform, halothane, enflurane and isoflurane) with formaldehyde were studied by ab initio MP2 and CCSD(T) methods. The CCSD(T)/CBS calculated binding energies of these complexes are between -2.83 and -4.21 kcal mol-1. The largest stabilization energy has been found for the C–Br---O bonded halothane---OCH2 complex. In all complexes the C–X bond length (where X = Cl, Br) is slightly shortened, in comparison to a free compound, and an increase of the C–X stretching frequency is observed. The electrostatic interaction was excluded as being responsible for the C–X bond contraction. It is suggested that contraction of the C–X bond length can be explained in terms of the Pauli repulsion (the exchange overlap) between the electron pairs of oxygen and halogen atoms in the investigated complexes.
Permanent Link: http://hdl.handle.net/11104/0198173