A new polymorph of 1,4-bis(imidazol-1-ylmethyl)benzene dihydrate and its hydrogen-bonded fivefold interpenetrated CdSO4network

Single crystals of a new polymorph of 1,4-bis(imidazol-1-ylmethyl)benzene dihydrate (bix x 2H(2)O), C(14)H(14)N(4) x 2H(2)O, have been obtained by the hydrothermal method. The asymmetric unit is composed of two independent half-bix molecules, one on an inversion center and one on a twofold axial site, and two water molecules. The disordered water molecules link into discrete tetrameric water units via two O-H...O hydrogen bonds, forming planar R(4)(4)(8) rings. These tetrameric water units and bix molecules are further linked by two O-H...N hydrogen bonds into a three-dimensional network in which an R(20)(20)(106) hydrogen-bonded ring is observed. These large rings lead to the formation of a fivefold interpenetrated network. If both the tetrameric water units and the bix molecules can be regarded as connected nodes, one single three-dimensional net can then be rationalized as a CdSO(4) network. This study indicates that topological methodology can be applied in some cases in order to understand the inherent characteristics of some hydrogen-bonded supramolecular assemblies.