title: Chiral Cyclometalated Platinum(II) and Palladium(II) Complexes with Derivatives of Thienylpyridine as Ligands: Helical Distortion of the Square Planar (SP-4) Geometry.
abstract: Four cis-bis-cyclometalated complexes of platinum(II) and palladium(II) have been synthesized with chiral substituted thienylpyridine ligands. These ligands are (5aR,6aS)-5,5a,6a,7-tetrahydro-6,6-dimethyl-3-(2'-thienyl)cyclopropa[g]isoquinoline (th4,5capy) (1), (6aR,7aS)-5,6,6a,7a-tetrahydro-7,7-dimethyl-2-(2'-thienyl)cyclopropa[h]quinoline (th5,6capy) (2), (6R,8R)-5,6,7,8-tetrahydro-9,9-dimethyl-2-(2'-thienyl)-6,8-methanoquinoline (th5,6betappy) (3), and (6R,8R)-5,6,7,8-tetrahydro-9,9-dimethyl-3-(2'-thienyl)-6,8-methanoisoquinoline (th4,5ppy) (5). Two complexes have a well-defined chirality at the metal center, due to the sterical interaction of the ligands. These complexes are Delta-Pt(th5,6capy)(2) (8) and Lambda-Pt(th5,6betappy)(thpy) (9). The crystal structure of 8 shows a strong distortion from the ideal square planar geometry. Crystals of Delta-Pt(th5,6capy)(2) (8) are tetragonal, space group P4(3)2(1)2, a = 13.407(1) Å, b = 13.407(1) Å, c = 14.860(2) Å, alpha = beta = gamma = 90 degrees, and Z = 4. Final R = 0.0237 and R(w) = 0.0450 for 2353 observed reflections. Compound 8 possesses a crystallographic C(2) symmetry.
authors.affiliation: Institute of Inorganic Chemistry, University of Fribourg, Pérolles, CH-1700 Fribourg, Switzerland, and Institute of Chemistry, University of Neuchâtel, Avenue de Bellevaux 51, CH-2000 Neuchâtel, Switzerland.
authors.forename: Michel
authors.initials: M
authors.lastname: Gianini
authors.forename: Alex
authors.initials: A
authors.lastname: von Zelewsky
authors.forename: Helen
authors.initials: H
authors.lastname: Stoeckli-Evans