Crystal structure of di-μ-hydroxido-κ(4) O:O-bis[bis(acetyl-acetonato-κ(2) O,O')cobalt(III)].

The dinuclear title complex, [Co2(C5H7O2)4(μ-OH)2] or [Co(acac)2(μ-OH)]2, where acac is acetyl-acetonate, is centrosymmetric with half of the mol-ecule per asymmetric unit. The mol-ecular structure is a dimer of octa-hedrally coordinated Co(III) atoms with four O atoms from two chelating acac ligands and two O atoms from bridging hydroxide ligands. The crystal packing features weak C-H⋯O inter-actions between neighboring mol-ecules, leading to the formation of chains normal to the ac plane. The hydroxide H atoms are not involved in hydrogen bonding because of the bulky acac ligands. This is the first crystal structure reported of a dimeric transition metal bis-acac complex with OH(-) as the bridging group.