The dimanganese complex shown can be oxidized reversibly by 1–3 electrons. X-ray crystal...

The dimanganese complex shown can be oxidized reversibly by 1–3 electrons. X-ray crystal structures for the neutral complex and the ions having charges of 1+ and 2+ have provided the following bond distances for the atoms in the MnCCMn chain:

Account for the trends in Mn—C and C—C distances. Be sure to take into account the relevant orbitals. (See S. Kheradmandan, K. Venkatesan, O. Blacque, H. W. Schmalle, H. Berke, Chem–Eur. J. , 2004 , 10 , 4872.)