2-cyclopropylglycinatobis(2,2'-bipyridyl)cobalt(III) diperchlorate and its dihydrate

The crystal structures of 2-cyclopropylglycinatobis(2,2'-bipyridyl)cobalt(III) diperchlorate, [Co(cpg)(2,2′-bpy)2](ClO4)2 (1), and its dihydrate [Co(cpg)(2,2′-bpy)2](ClO4)2·2H 2O (2), are the first reported structures of a metal complex of 2-cyclopropylglycinate. Mixtures of the two kinds of crystals are formed from solutions that contain an excess of the δ-R/λ-S diastereoisomer. This diastereoisomer predominates in the solid state, but small amounts of the δ-S/λ-R diastereoisomer are also present, creating a disordered structure. Modelling the disorder to fit the diffraction data gives a diastereoisomeric composition of the crystals that is consistent with the nuclear magnetic resonance data.