Neutral spin-delocalized mixed-valence manganese(I)-manganese(II) dimers bridged by alkoxide, imidazolate, or malonodinitrile anions. Inorganic Chemistry, (25)27:4865--4870, 1986. [PUMA: complex;manganese valence;imidazolate dimeric complex;intervalence complex mixed manganese valence complex;malononitrile transition anion complex;ESR alkoxide]