Comparison of mol-ecular structures of -bis-[8-(di-methyl-phosphan-yl)quinoline]-nickel(II) and -platinum(II) complex cations.

The crystal structures of the complexes (-4-2)--bis-[8-(di-methyl-phosphan-yl)quinoline-κ ,]nickel(II) bis-(perchlorate) nitro-methane monosolvate, Ni(CHNP)·CHNO (), and (-4-2)--bis-[8-(di-methyl-phos-phan-yl)quinoline-κ ,]platinum(II) bis-(tetra-fluoro-borate) aceto-nitrile monosolvate, Pt(CHNP)·CHN (), are reported. In both complex cations, two phosphanyl-quinolines act as bidentate -donating chelate ligands and form the mutually configuration in the square-planar coordination geometry. The strong influence of the di-methyl-phosphanyl donor group is confirmed by the Ni-N bond lengths in , 1.970 (2) and 1.982 (2) Å and, the Pt-N bond lengths of , 2.123 (4) and 2.132 (4) Å, which are relatively long as compared to those in the analogous 8-(di-phenyl-phosphan-yl)quinoline complexes. Mutually -positioned quinoline donor groups would give a severe steric hindrance between their -H atoms. In order to reduce such a steric congestion, the Ni complex in shows a tetra-hedral distortion of the coordination geometry, as parameterized by τ = 0.199 (1)°, while the Pt complex in exhibits a typical square-planar coordination geometry [τ = 0.014 (1)°] with a large bending deformation of the ideally planar MePqn chelate planes. In the crystal structure of , three F atoms of one of the BF anions are disordered over two sets of positions with refined occupancies of 0.573 (10) and 0.427 (10).