Hydrogen and coordination bonds in isostructural systems. Are hydrogen bonds unique?

Abstract

Reliable spectral criteria which allow comparison of the hydrogen and coordination bonds in isostructural systems are suggested. The model systems consist of ArXH and ArXMR n (X = O, S, N; M = Hg, Sn, Pb, Sb; Ar = C 6H 4Y where Y = COR, NO 2, C 5H 4N, etc.) which interact with various N-, P- and O-bases. The conditions on which the ν XM vibrations are local, have been established. Examination of thiol derivatives reveals the similarity of spectral (IR, Raman) effects for coordination and hydrogen bonds in the ν XM and ν XH regions, respectively. The character of dependence of a proton and a bulky organometallic cation transfer on medium, a heteroatom X or a base is shown to be similar. Some quantitativeand qualitative relationships between XH and XM bond polarities and the capacity to form complexes, ionic pairs or ions are found. Comparison of spectral properties of isostructural systems with hydrogen and coordination bonds does not reveal the uniqueness of the H bond.