(Tetramethylcyclobutadiene)cobalt complexes with arene ligands. Arene replacement: X-ray diffraction and quantum chemical studies

The structures of the complexes [Cb*Co(eta 6-indane)] center dot PF6 (1 center dot PF6, Cb* = C4Me4) and [Cb*Co(eta 6-naphthalene)] center dot PF6 (2 center dot PF6) were determined by X-ray diffraction. The dissociation energies of Co-arene bonds in cations 1 and 2 and in related derivatives containing benzene, o-xylene, and anthracene ligands were estimated by DFT calculations. The effect of substituents in the arene ligand on the direction of the nucleophilic attack by acetonitrile during the arene replacement was analyzed.