Synthesis and Structural Study of Tris(-pyrazolyl)hexakis(pyrazole)dicobalt(III) Nitrate

Abstract

The new (Hpyz)3Co(μ2-pyz)3Co complex has been isolated as the nitrate salt through a reaction of Co(II) nitrate, Hpyz (pyrazole), triethylamine, and oxygen. The salt crystallizes in the monoclinic space group P21/m with a = 12.5977(3) Å, b = 15.3387(4) Å, c = 14.0800(3) Å, β = 93.0868(15)°, and = 1.464 g/cm3 at 150(1) K. The complex, with pseudo-octahedral coordination about the equivalent cobalt centers, has shorter Co–N distances for the bridging anionic pyz ligands as compared to the neutral Hpyz ligands, with the averages being 1.918(2) and 1.966(4), respectively. The Co–Co separation is 3.568 Å, reflecting the absence of any significant metal-metal interaction.