Dichlorido[2-diphenylphosphanyl-N-(pyridin-3-ylmethyl)benzylidenamine-κ2 P,N]platinum(II)

The title compound, [PtCl2(C25H21N2P)], is a PtII complex with an NPCl2 coordination sphere in which the metal is coordinated to the imino N and phosphane P atoms of the ligand and to two chloride ions. The PtII atom is in a distorted square-planar environment and is bound to the ligand via the P and amine N atoms in a cis fashion, with the chlorine atoms located at the two remaining sites.

The title compound, [PtCl 2 (C 25 H 21 N 2 P)], is a Pt II complex with an NPCl 2 coordination sphere in which the metal is coordinated to the imino N and phosphane P atoms of the ligand and to two chloride ions. The Pt II atom is in a distorted square-planar environment and is bound to the ligand via the P and amine N atoms in a cis fashion, with the chlorine atoms located at the two remaining sites.

Comment
In recent years, platinum complexes with iminophosphane ligands of the N- [(2-diphenylphosphanyl)benzylidene]amine type have been used as catalysts (or catalyst precursors) in a variety organic reactions. To the best of our knowledge, no structures have been determined so far, concerning the free ligand -(2(diphenylphosphanyl) benzylidene) (phenyl) methanamine, where the potentially bidentate ligand is chelated to the metal through the phosphorus and imino nitrogen atoms (Fig. 1).
The platinum is in a square-planar environment and it is bound to the ligand using a k 2 P,N interaction in a cis fashion, with the chlorides located at the two remaining sites. However the square-planar geometry of the platinum environment is distorted with the angles being less than 180°, N(1)-Pt(1)-Cl(2) and P(1)-Pt(1)-Cl(1) of 176.70 (12)° and 178.20 (5)°, respectively. The average Pt-N and Pt-P bond lengths of 2.040 (4) and 2.1999 (13) Å, respectively are in the range expected for iminophosphane platinum(II) complexes, Ankersmit et al.,1996. The torsion angle Pt-P-C(9)-C(8) = -36.5 (4)° indicates that the =CHC 6 H 4 -unit lies below the PtCl 2 (P,N) plane. Selected bond lengths are given in Table 1.

Experimental
To a dry CH 2 Cl 2 (10 ml) solution of the precursor [Pt(COD)Cl 2 ] was added an equimolar amount of (2(diphenylphosphanyl) benzylidene) (phenyl)methanamine in CH 2 Cl 2 (10 ml) solution, and the reaction was stirred at room temperature for 1 hr.
The yellow solution was concentrated under reduced pressure to half volume and the addition of ca 10 ml hexane caused precipitation of the complex, which was filtered off, washed with Et 2 O and dried under vacuum for 4 hrs. Yellow crystals used in the X-ray diffraction studies were grown by slow evaporation of a solution of the compound in a CH 2 Cl 2 -hexane solution at room temperature.

Refinement
The methyl, methine and aromatic H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H = 0.95 Å for aromatic, C-H = 0.99 Å for i Pr CH, C-H = 0.95 Å for CH and C-H = 0.98 for Me groups.
supplementary materials sup-3 Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.