PREPARATIVE AND STRUCTURAL CHEMISTRY OF CHIRAL P,N-BIDENTATE COMPLEXES OF PALLADIUM(II) AND PLATINUM(II)

The preparations of the valine-derived chiral (L) P,N-bidentate ligand (p-CH3C6H4)2PCH2CH(Pri)NHCH2(P-OCH3C6H4) (1), the complexes PdCl2(1) (2) and PtCl2(1) (3), and the deprotonated dimeric compound [Pt(1 -H)Cl]2 (4), as well as the iodo analog of 3, are reported. The solid-state structure of 2 has been determined by X-ray diffraction and shown to contain a five-membered metal chelate in which the N-benzyl and Pri groups are equatorial, whereas the solution-state structure, determined by using one- and two-dimensional H-1-NMR methods, is shown to have both of these groups pseudoaxial. The results are discussed with the help of molecular mechanics calculations and solid-state P-31-NMR methods. H-1, C-13, N-15, and P-31 results are reported. Crystals of 2.0.5CHCl3 are orthorhombic, of space group P2(1)2(1)2(1), with a = 13.230 (4) angstrom, b = 17.133 (9) angstrom, c = 25.877 (8) angstrom, Z = 8, and V = 5865 (3) angstrom3.