Interdigitation, interpenetration and intercalation in layered cuprous tricyanomethanide derivatives

Reaction of Cu(I), tricyanomethanide (tcm , C(CN)3-) and L = either hexamethylenetetramine (hmt), 4,4'-bipyridine (bipy) or 1,2-bis(4-pyridyl)ethene (bpe) gives crystals of [Cu(tcm)(hmt)] (1), [Cu(tcm)(bipy)] (2) and [Cu(tcm)(bpe)] x 0.25 bpe x 0.5 MeCN (3), respectively. Crystal structure analysis shows 1-3 all contain closely related puckered (4,4) sheets composed of tetrahedral Cu(I) ions bridged by 2-connecting tcm- and L. The crystal packing, however, varies markedly with L. In 1 the sheets interdigitate in pairs. In 2 the sheets participate in parallel interpenetration in pairs. In 3 guest bpe and MeCN molecules are intercalated in channels formed by the stacking of the sheets.