Triaceto-nitrile-(1,4,7-trimethyl-1,4,7-tri-aza-cyclonona-ne)cobalt(II) bis-(tetra-phenyl-borate).

The title cobalt(II) complex, Co(CHN)(CHN) or [(tacn)Co(NCMe)][BPh], has been characterized by single-crystal X-ray diffraction. It incorporates the well-known macrocyclic tacn (1,4,7-trimethyl-1,4,7-tri-aza-cyclo-nona-ne) ligand, which is coordinated facially to the metal center. The complex crystallizes in space group 2/ with = 4. The divalent cobalt ion exhibits a six-coordinate octa-hedral geometry by one tacn and three aceto-nitrile ligands. Two non-coordinating tetra-phenyl-borate (BPh ) anions are also present.