Low-temperature X-ray structural analysis of propanedinitrile derivatives substituted with a bis(4-dimethylaminophenyl)methyl group: the origin of elongation of the donor–acceptor substituted C–C bond†
Abstract
Push–pull type substitution at Csp3–Csp3 in the title compounds does not have special electronic effects on the bond length, and the observed expansion can be best accounted for by steric interaction between substituents.