Journal of Physical Chemistry A, Vol.113, No.30, 8626-8634, 2009
Water-Chloride and Water-Bromide Hydrogen-Bonded Networks: Influence of the Nature of the Halide Ions on the Stability of the Supramolecular Assemblies
Two compounds, namely, [TTPH2](Cl)(2)center dot 4H(2)O (1) and [TTPH2](Br)(2)center dot 4H(2)O (2), (TTP = 4'-p-tolyl-2,2':6',2 ''-terpyridine) were synthesized from purely aqueous media and characterized by physical techniques. In the solid-state structures of these compounds, interesting supramolecular assemblies are observed. In 1, an unusual staircase-like architecture of the tape of edge-shared planar water hexamer is of importance, where the chloride ions are at the two edges of the tape. In 2, the polymeric nature of the water-bromide assembly is of interest, where discrete open-cube water octamers are doubly bridged by bromide ions. Semiempirical and DFT calculations confirm that the nature of the anion indeed affects the topology of the water-halide assemblies. We conclude that the protonated [TTPH2](2+) species can act as appropriate receptors for halide ions, which in turn act as a matrix for the formation of polymeric ID water-halide assemblies.