Preparation, crystal and molecular structure and properties of 5,5′-bis-(1,3-dithiol-2-ylidene)[bicyclopenta-1,3-dien-1-yl]-2,2′,3,3′-tetracarbonitrile
Abstract
The synthesis and properties of 2-(3,4-dicyanocyclopenta-2,4-dienylidene)-1,3-dithiole 2have been, previously reported. NMR spectral data of that compound imply a large contribution of the dipolar form to its electronic structure. Two-solvent diffusion recrystallization, in the presence of O2, yields the title compound 3, the crystal structure of which is reported here. This appears to be the first crystal structure of a compound containing the dicyanocyclopentadiene moiety. The space group is P1–, and the lattice parameters are a= 8.3617(19), b= 11.1196(23). c= 12.8159(20)Å, α= 96.587(15)°, β= 103.103(15)°, γ= 109.917(16)° and V= 1066.9(4)Å°3 for Z= 2. We also discuss a plausible mechanism for the formation of compound 3, and its spectral properties.