Synergistic cation-to-anion and anion-to-cation interactions in the binding of oxoanions: Syntheses, characterizations, and single-crystal structures of [Co(phen)_2CO_3]ClO_3, [Co(phen) _2CO_3]BrO_3·3.5H_2O and [Co(phen)_2CO_3]IO_4

摘要

The syntheses, physical, spectroscopic characterizations and crystal structures of [Co(phen)_2CO_3]ClO_3, [Co(phen)_2CO_3]BrO_3·3.5H_2O and [Co(phen)_2CO_3]IO_4 are described (phen = 1,10-phenanthroline, C_(12)H_8N_2). The crystal structures feature "synergistic" directional bonding interactions including cation-to-anion C-H?O(anion) bonds and anion-to-cation Cl?π and I-O?π bonds, as well as cation-to-cation C-H?O(carbonato) and π - π stacking interactions. The bromate structure also features distinctive O-H?O hydrogen bonding networks involving the water molecules. The facile formation of this series of complex salts with relatively small K_(sp) values suggests that the [Co(phen)_2CO_3]~+ complex ion may be effective as a binding agent for oxo-anions containing halogen atoms(halates) in an aqueous environment.