Synthesis and crystal structures of π complexes of copper(I) halides with diallyl disulfide 2CuX · DADS (X = Cl, Br; DADS = CH2=CH-CH2-S-S-CH2-CH=CH2)

Compounds 2CuCl · DADS (I) and 2CuBr · DADS (II) (DADS is diallyl disulfide) are prepared by the ac electrochemical synthesis, and their crystal structures are determined. The complexes are isostructural, space group P21/n, Z = 4; I: a = 8.995(2) Å, b = 12.541(2) Å, c = 9.644(2) Å, β = 98.74(2)°, V = 1075.3(4) Å3, II: a = 9.064(2), b = 12.878(3), c = 9.832(2) Å, β = 98.61(3)°, V = 1134.7(4) Å3. In complexes I and II, the tetradentate DADS ligand is chelate-bridging and is coordinated by two crystallographically independent copper atoms of two inorganic Cu4X4 fragments. An insignificantly distorted tetrahedral environment of each of the two copper atoms consists of the olefin group, sulfur atom, and two halogen atoms. The complexes are stabilized additionally by the formation of C-H⋯S hydrogen bonds involved in characteristic seven-membered rings in the structures.