A. Graham, R. Fenn
Nov 1, 1970
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0
Influential Citations
43
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Abstract The crystal structure and molecular configuration of the complex (isothiocyanato)dicarbonyl-1,10-phenanthroline(2-methylallyl)molybdenum, NCS(CO)2(C12H8N2)(C4H7)Mo have been determined from three dimensional data collected photographically at 20°. The unit cell is monoclinic, spacegroup P21/c with four formula units per cell of dimensions a = 8.034±0.004, b = 13.406±0.001, c = 17.869±0.009 A; β = 105°5′±5′. The structure has been refined to R = 0.1135 by the application of isotropic/anisotropic block-diagonal-approximation least-squares refinement using 3106 independent non-zero reflections. The complex has essentially an octahedral arrangement of ligands. If it is viewed with the plane of the dicarbonyl ligands horizontal, the methallyl and isothiocyanato ligands lie axially, one on each side of the dicarbonyl plane. The phenanthroline ligand plane lies 27.5° below the horizontal, dipping away from the methallyl. The other interplanar angles are methallyl/dicarbonyl 7.6°; phenanthroline/methallyl 34.4°. The central allylic carbon atom is closer to the molybdenum, at 2.274±0.012 A, than the two terminal (CH2 type) carbon atoms at 2.320±0.012 A and 2.350±0.012 A. The allylic CH2CCH2 angle is 111.5±1.1° and the CCH2 (mean) and CCH3 bond lengths are 1.428±0.017 A and 1.491±0.017 A respectively. The methyl carbon atom is 0.044 A out of the plane defined by the three CH2CCH2 carbon atoms representing a distortion of less than 2°. The mean MoC (carbonyl) and CO bond lengths are 1.969±0.010 A and 1.146±0.015 A, respectively. The thiocyanato ligand is in the iso-form, the MoN distance being 2.146±0.009 A, with bond lengths NC at 1.168±0.014 A and CS at 1.613±0.012 A.