(Naphthalene-2,3-diolato-κ(2)O,O')[tris-(pyridin-2-ylmeth-yl)amine-κ(4)N]cobalt(III) tetra-phenyl-borate acetone monosolvate hemihydrate.

In the title salt, [Co(C(10)H(6)O(2))(C(18)H(18)N(4))](C(24)H(20)B)·C(3)H(6)O·0.5H(2)O, the Co(III) ion in the complex cation is six-coordinated in a rigid octa-hedral N(4)O(2) geometry. The asymmetric unit contains one complete [Co(C(10)H(6)O(2))(C(18)H(18)N(4))](+) unit, one tetraphenylborate counter-anion and one acetone and one water mol-ecule that is located on an inversion centre. All the features of the Co(III) ion are fully consistent with the formulation of the cation as a Co(3+)-catecholate complex. Variable-temperature magnetic measurements in the region 2-380†K show a obvious diamagnetism over the observed temperature range.