Die Kristallstruktur von Tricarbonyl(2.6-di-tert-butyl-pyridin)chrom(0) bei 200 K / Crystal Structure of Tricarbonyl(2,6-di/tert-butyl-pyridine)chromium(0) at 200 K
Based on single crystal X-ray diffraction data the crystal structure of tricarbonyl(2,6-dwmbutyl- pyridine)chromium(0) has been determined at 200 K: space group P 21/n, Z = 4, lattice constants a = 680.6(5), b - 1383.3(10), c = 1763.0(16) pm, β = 96.53(8)°, refinement to Rw - 0.048 for 1672 independent reflections with FO > 2 σ. The chromium atom is η6π6- bonded to the essentially planar pyridine ring (Cr-C: 219-222 pm, Cr-N: 221 pm). The CO ligands show “eclipsed” orientation with respect to the 2, 4 and 6 position of the pyridine ring. Two CO groups fit into the gaps formed by two methyl groups of the tert-butyl substituents in 2 and 6 position, respectively. The results are discussed in context with related arene and λ3-phosphorine complexes