Crystal structure of Carbonatohydroxo(2,2':6',2'-terpyridyl)cobalt(III) tetrahydrate

Abstract

The crystal structure of the title compound, [Co(terpy)(CO₃)(OH)],₄H₂O, has been determined at 295 K by single-crystal X-ray diffraction and the use of diffractometer data, and refined by least squares to a residual of 0.075 for 1354 ?observed? reflections. Crystals are triclinic, Pī, a 11.407(6), b 10.566(6), c 8.445(4) Ǻ, α 100.21(5), β 107.35(5), γ 102.18(5)°, Z2. The structure of the molecule is unusual for a 1 : 1 transition metal/terpy complex in that the other ligating atoms are non-halide and the complex six-coordinate. The remaining three coordination positions about the metal are occupied by the bidentate carbonate (Co-O 1.918(9), 1.918(8) Ǻ) and the hydroxide ion (Co-O 1.894(10) Ǻ). The Co-N distances are appreciably shorter than those observed in other terpy systems (Co-N(central) 1.848(8); Co-N(outer) 1.946(9), 1.952(9) Ǻ).