catena-Poly[zinc-tris­(μ-dimethyl­carbamato-κ(2) O:O′)-zinc-μ-(2-phenyl­benzimidazolido-κ(2) N:N′]

The crystal structure of the title compound, [Zn(2)(C(13)H(9)N(2))(C(3)H(6)NO(2))(3)](n), displays a long chiral chain. This is composed of zinc-dimer clusters capped by dimethyl­carbamate ligands, which lie on crystallographic twofold rotation axes and are polymerically linked in one dimension by 2-phenyl­benzimidadole (2–PBImi) organic ligands. The two Zn(2+) ions defining the dimetal cluster are crystallographically independent, but display very similar coordination modes and tetra­hedral geometry. As such, each Zn(2+) ion is coordinated on one side by the N-donor imidazole linker, while the other three available coordination sites are fully occupied by the O atoms from the capping dimethyl­carbamates. The chirality of the chain extends along the c axis, generating a rather long 52.470 (11) Å cell axis. Inter­estingly, the chiral material crystallizes from completely achiral precursors. A twofold axis and 3(1) screw axis serve to generate the long asymmetric unit.