Bis(cis-1,4-diphenyl-1,4-diphosphacyclohexane-κ²P,P′)platinum(II) bis(tetrafluoridoborate)

Abstract

Key indicators: single-crystal X-ray study; T = 373 K; mean (C-C) = 0.002 Å; R factor = 0.016; wR factor = 0.033; data-to-parameter ratio = 30.6.The title complex, [Pt(C 16 H 18 P 2 ) 2 ](BF 4 ) 2 , possesses a crystallographically imposed center of symmetry occupied by a Pt II ion, which is coordinated by four P atoms from two 1,4diphenyl-1,4-diphosphacyclohexane ligands in a distorted square-planar geometry. Related literatureThe corresponding complexes with both Pt II and Pd II have been previously reported as chloride salts (Mason et al., 2006). For related literature, see: Brooks et al. (1989). Bis(cis-1,4-diphenyl-1,4-diphosphacyclohexane-2 P,P')platinum(II) bis(tetrafluoridoborate) T. S. Morey, S. M. Miller and M. L. Helm CommentThe crystal structure of (I) consists of [Pt(C 16 H 18 P 2 ) 2 ] 2+ cations and BF 4 − anions (Fig. 1). The cation shows a distorted square planar geometry around the metal center with two non-coordinating BF 4 − anions. The P-Pt-P bite angle observed in the structure is 72.908 (13)°. Additionally, the phenyl substituents on the phosphorus atoms are arranged in a parallel fashion, with a distance between the center of the phenyl rings of 3.727 Å and a dihedral angle of 2.15 (4)° between the rings. The parallel arrangement of phenyl rings is not, however, repeated in the unit cell between individual molecules. The parallel arrangement of the phenyl rings within the molecule was also observed in the previously reported analogous Pt II an Pd(II) chloride complexes (Mason et al., 2006). ExperimentalThe synthesis of (I) was completed through reaction of the previously reported chloride salt with an excess of AgBF 4 , followed by filtration to remove the solid AgCl (Mason et al., 2006, Brooks et al., 1989. Crystals where grown by slow vapor diffusion of diethylether into a saturated chloroform solution of (I). RefinementAll H atoms were placed in calculated positions and constrained to ride on their parent atoms, with C-H distances in the range of 0.93-0.97 Å, with U iso (H) = 1.2 times U eq (C).

Group 9 half-sandwich complexes containing the unique P,P′-diphenyl-1,4-diphospha-cyclohexane ligand: Synthesis, X-ray structure analyses and spectroscopic studies

“…Previous work conducted by Panunzi et al on the metal coordination properties of this ligand demonstrate its versatility towards binding M(II) centers (M = Co, Ni, Pd and Pt) [10]. Furthermore, previous work from our laboratories have resulted in the formation and structural characterization of [M(dpdpc) 2 ]Cl 2 , (M = Pd, Pt) complexes [11,12]. Interestingly, these complexes show an average 73°P-M-P bite angle, much smaller then that for typical acyclic bidentate phosphines.…”

Synthesis, characterization and crystal structure of (cis-P,P′-diphenyl-1,4-diphospha-cyclohexane)molybdenum(0)tetracarbonyl

“…R 2 P-C-C-PR 2 ), research on cyclic bidentate phosphines with two connecting carbon chains (i.e. RP(-C-C-) 2 PR) has recently received attention [3][4][5][6][7]. Such compounds are of particular interest due to the fact that the phosphorus atoms are held in a rigid steric position that could lead to distorted metal coordination geometries and different reaction chemistry than seen in their acyclic counterparts.…”

“…Refluxing a mixture of Mo(CO) 6 with one equivalent of the phosphine ligand, dpdpc, in diglyme for 1 h affords the metal complex (dpdpc)Mo(CO) 4 as determined by 31 P{ 1 H} NMR (Scheme 1). Removal of solvent by distillation, followed by dissolution in CH 2 Cl 2 , filtration through celite, and removal of the solvent results in pure Mo(dpdpc)(CO) 4 in 15% yield [11].…”