Dichlorido{N-[2-(diphenylphosphanyl)benzylidene]isopropylamine-κ2 N,P}palladium(II) dimethyl sulfoxide monosolvate

In the title PdII complex, [PdCl2(C22H22NP)]·(CH3)2SO, the PdII atom is coordinated in an NPCl2 coordination sphere by the N(imino) and P(phosphane) atoms of the ligand and by two Cl− ions in a slightly distorted square-planar geometry [r.m.s. deviation = 0.081 (3) Å, plane defined by the four atoms around the Pd atom]. The dimethyl sulfoxide solvent molecules form centrosymmetric dimers due to an intermolecular C—H⋯O interaction. The crystal structure is further stabilized through two intermolecular C—H⋯π interactions.

In the title Pd II complex, [PdCl 2 (C 22 H 22 NP)]Á(CH 3 ) 2 SO, the Pd II atom is coordinated in an NPCl 2 coordination sphere by the N(imino) and P(phosphane) atoms of the ligand and by two Cl À ions in a slightly distorted square-planar geometry [r.m.s. deviation = 0.081 (3) Å , plane defined by the four atoms around the Pd atom]. The dimethyl sulfoxide solvent molecules form centrosymmetric dimers due to an intermolecular C-HÁ Á ÁO interaction. The crystal structure is further stabilized through two intermolecular C-HÁ Á Á interactions.

Comment
In recent years, palladium 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, only a few structures have been determined so far, concerning the free ligand (2-diphenylphosphanyl-benzylidene)-isopropylamine, where the potentially bidentate ligand is chelated to the metal through the phosphorus and imino nitrogen atoms ( Fig. 1). The title compound (I) has been synthesized earlier but there have been no reports of the crystal structure: the Pd II center adopts a slightly distorted square planar geometry in with an r.m.s. deviation of 0.081 (3) Å from the planar geometry.
Selected bond lengths are given in table 1.
In the structure of (I) the (CH 3 ) 2 SO molecules are connected through a weak C-H···O intermolecular interaction forming centrosymmetric dimers (Fig. 2). In addition, the crystal lattice is further stabilized through two C-H···π intermolecular interactions (Fig 3). C10-H10···π (Cg of C11 to C16 atoms ring) joins two of the complex molecules into centrosymmetric dimers. Those combined with the C8-H8···π (Cg of C17 to C22 atoms ring) interaction, make additional rings composed of four complex molecules for further stabilization of the crystal lattice.

Experimental
To a dry CH 2 Cl 2 (10 ml) solution of the precursor [Pd(COD)Cl 2 ] (0.095 g, 0.3 mmol) was added isopropylamine (0.018 g, 0.3 mmol) 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/ (CH 3 ) 2 SO (1:1) 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. Fig. 1. View of (I) (50% probability displacement ellipsoids).    (3)