Molecular properties of a bis(1,1-diphenylallenylidene)-octacarbonyltriiron complex obtained by symmetric cleavage from 1,1,6,6-tetraphenylhexapentaene. Idealized symmetry studied in synperiplanar and synclinal conformers byX-ray diffraction, NMR and density functional theory

Molecular deviations from symmetry of bis(1,1-diphenylallenylidene)-octacar bonyltriiron are compared in two distinct synperiplanar and synclinal confo rmers expressed as two polymorphic forms by the analysis of close contacts in crystals, quantum chemical DFT calculations for the isolated molecules a nd by C-13-NMR in solution. (C) 2001 Published by Elsevier Science B.V.