CHARGE-TRANSFER COMPLEXES OF BENZYLVIOLOGEN NZYL-4,4'-BIPYRIDINIUM(2-9(CN)(15)CENTER-DOT-H2O() CATION) WITH CYANOCUPRATE(I) AND THE STRUCTURE OF (BZV)(3)CU)

Reactions between 1,1'-dibenzyl-4,4'-bipyridinium(2+) (benzylviologen, BzV) chloride and cyanocuprates(I) gave two charge-transfer complexes having different colors: dark brown (BzV)(3)Cu-9(CN)(15). H2O and lig ht brown (BzV)Cu(CN)(3) . 2H(2)O. An Xray crystal analysis of the form er compound showed that nine crystallographically nonequivalent Cu ato ms form three kinds of triad -Cu-(CN)-Cu- screws, which are linked by CN groups resulting in a unique three-dimensional network structure. T hree of the nine Cu atoms have distorted tetrahedral (td) coordination geometries while the others have triangular plane (tp) geometries. Ea ch screw consists of a (-tp-td-tp-)(n) array. There are three crystall ographically nonequivalent viologen molecules. Certain CuCN moieties a re located above a viologen ring or by the side of a viologen ring, wi th close interatomic contacts. These close contacts are characteristic of the charge-transfer complex and are responsible for the deep color of the complex.