Crystal and mol­ecular structures of di­chlorido­palladium(II) containing 2-methyl- or 2-phenyl-8-(diphenyphosphan­yl)quinoline

The crystal structures of di­chlorido­palladium(II) complexes bearing 2-methyl- and 2-phenyl-8-(di­phenyl­phosphan­yl)quinoline, namely, di­chlorido­[8-(di­phenyl­phosphan­yl)-2-methyl­quinoline-κ(2) N,P]palladium(II), [PdCl(2)(C(22)H(18)NP)] (1) and di­chlorido­[8-(di­phenyl­phosphan­yl)-2-phenyl­quinoline-κ(2) N,P]palladium(II), [PdCl(2)(C(27)H(20)NP)] (2), were analyzed and compared to that of the 8-(di­phenyl­phosphan­yl)quinoline (PQ(H)) analogue (3). In all three complexes, the phosphanyl­quinoline moiety acts as a bidentate P,N-donating chelate ligand. In the PQ(H) complex (3), the Pd(II) center has a typical planar coordination environment; however, both the methyl- and phenyl-substituted phosphanyl­quinoline (PQ(Me) and PQ(Ph), respectively) complexes (1) and (2) exhibit a considerable tetra­hedral distortion around the Pd(II) center, as parameterized by the τ(4) values of 0.1555 (4) and 0.1438 (4) for (1) and (2), respectively. The steric inter­action from the substituted group introduced at the 2-position of the quinoline ring enforces the cis-positioned Cl ligand to be displaced from the ideal coordination plane. Also, the ideally planar phosphanyl­quinoline five-membered chelate ring shows a large bending deformation by the displacement of the Pd(II) center from the quinoline plane. In addition, in the phenyl-substituted complex (3), the coordinating quinolyl and the substituted phenyl rings are not co-planar to each other, having a dihedral angle of 33.08 (7)°. This twist conformation prohibits any inter­molecular π–π stacking inter­action between the quinoline planes, which is observed in the crystals of complexes (1) and (2).