Two copper complexes with N,N '-diallylbenzimidazolium chloride: Synthesisand crystal structure of [C13H15N2](2)(+)[(CuCl4)-Cl-II](2-) and [C13H15N2](+)[Cu(2)(I)Cl3](-)

Crystals of [C13H15N2](2)(+) [(CuCl4)-Cl-II](2-) (I), which transform into crystals of the pi-complex [C13H15N2](+)[(Cu2Cl3)-Cl-I](-)(II) during the e xperiment, were prepared by ac electrochemical synthesis from CuCl2 . 2H(2) O and N,N-diallylbenzimidazolium chloride in alcohol medium. The X-ray diff raction study (DARCh-1 automated single-crystal diffractometer, MoKalpha ra diation, graphite monochromator) has shown that crystals of I are orthorhom bic, space group Fddd, a = 26.220(5), b = 28.405(6), c = 7.714(2) Angstrom, rho(calcd)= 1.3963(8) g/cm(3) Z = 8. Crystals of II are monoclinic, space group C2/c, a = 12.197(9), b = 17.105(9), c = 7.793(6) Angstrom, beta = 109 .89(8)degrees rho(calcd)= 1.880(5) g/cm(3), Z = 4. Structure I is built fro m the N,N'-diallylbenzimidazolium cations, whose heterocyclic fragments are stacked parallel to each other along [001], and (CuCl42-)-Cl-II anions. Th e copper atom has a distorted tetrahedral environment, untypical of the oxi dation state +2. In structure II, copper and chlorine atoms form the Cu-2(I ) Cl-3(-) anions with the short Cu-Cu contacts of length 2.889(6) Angstrom. The bridging ligand cation is bonded to the copper atoms through the C=C b onds of both allyl groups, thus forming infinite [001]-directed chains asso ciated into a three-dimensional framework by the C-H ... Cl bonds.