CROSS-CONJUGATED POLYENES / Part III. The molecular structures of gaseous bis(4,4-dimethyl-2,5-cyclohexadiene-1-ylidene) and 4,4-dimethyl-1-methylene-2,5-cyclohexadiene

Article abstract of DOI:10.1016/0022-2860(82)80081-1

The molecular structures of bis(4,4-dimethyl-2,5-cyclohexadiene-1-ylidene) (1) and 4,4-dimethyl-1-methylene-2,5-cyclohexadiene (2) have been studied by the gas electrondiffraction method.Both molecules were found to have non-planar carbocyclic rings that may be described by C6-C1-C2=C3 dihedral angles of 9.7 and 7.9 deg respectively for the former and latter compounds.The CC double bond at the bridge in the pentaene molecule (1) was found to be significantly longer than those in the ring <1.382(8) vs. 1.350(3) Angstroem>.