Structural Aspects of Pt(³-P¹C₂X¹C₂P2)(Y) Derivative Types

In this structural study, structural data are classified and analyzed for almost seventy complexes of the general formula Pt(eta(3)-(PXP2)-X-1-P-1)(Y) (X-1 = O, N, C, S, Si) and (Y = various monodentate ligands), in which the respective eta(3)-(PXP2)-X-1-P-1 ligand forms a pair of five-membered metallocyclic rings with a common X-1 atom of the (PC2XC2P2)-C-1-C-1 type. The present complexes crystallize in five crystal systems: trigonal (1x), tetragonal (1x), orthorhombic (11x), triclinic (18x), and monoclinic (39x). In 69 complexes, a eta(3) ligand with monodentate Y constructs a distorted square planar geometry around each Pt(II) atom. There is only one complex in which Pt(eta(3)-(PSiP2)-Si-1-P-1)((PPh3)-Ph-3) constructs a trigonal-pyramidal geometry around a Pt(II) atom. The three P atoms construct a trigonal plane, and the Si atom occupies a pyramid. The structural data are discussed from various points of view, including the covalent radii of the atoms, the degree of distortion, and trans-influence. The trans-effect on the Pt-L bond distance also affects the L-PT-L bond angles, as well as the distortion of square planar geometry around Pt(II) atoms.