Axial ⇌ basal isomer distributions in cyclic and acyclic (η4-diene)Fe(CO)2PPh3 complexes

Abstract

(Diene)Fe(CO)₂PPh₃ complexes exist in solution as isomeric mixtures with phosphine in the axial or basal position of the square pyramidal structure, methyl substitution at the internal diene carbon or trans-disubstitution at the terminal diene carbon increasing the concentration of axial isomer; cis- or trans-monosubstitution or cis-disubstitution at the terminal carbon increases the concentration of basal isomer.