Original articleIntra-ring haptotropic rearrangements of Mn(CO)3 in fluorenyl ligands

Geometric parameters, and intra-ring haptotropic rearrangements π-π (intra-ring-HRs) ŋ5⇌ŋ3 of the manganesetricarbonyl complexes (ŋ5-9-R-C13H8)Mn(CO)3, R = But and Ph in 18e zero-valence are carried out using density functional theory DFT at PBE/TZP level. The calculated activation barriers to ŋ5⇌ŋ3 intra-ring HR in (ŋ5-9-R-C13H8)Mn(CO)3, R = But and Ph are (28.5 and 69.5 kcal.mol−1 respectively). The compute of HOMA and FLU indexes indicates the reduction of aromaticity when going from free to coordinated complex. The energy decomposition analysis reveals the dominant ionic character in manganese-Cp bond in the presence of covalent contribution.