title: Cis-trans isomerism in a square-planar platinum(II) complex bearing bulky fluorinated phosphane ligands.
abstract: Transition-metal complexes bearing fluorinated phosphane and thiolate ligands has been an area of study in recent years and the chemical context of the current work is related to the metal-assisted functionalization of fluorinated derivatives. The cis and trans isomers of the square-planar complex bis[(pentafluorophenyl)diphenylphosphane-κP]bis(2,3,5,6-tetrafluorobenzenethiolato-κS)platinum(II), [Pt(C6HF4S)2{P(C6H5)2(C6F5)}2], have been crystallized from a single chromatographic fraction and characterized by X-ray diffraction analysis. The stabilization of the cis isomer results from weak intramolecular π-stacking interactions and possibly from the formation of a C-F...Pt contact, characterized by an F...Pt separation of 2.957 (6) Å. The natural bond orbital analysis (NBO) for this isomer confirms that the corresponding F → Pt charge transfer accounts for 6.92 kcal mol(-1) in the isomer stabilization. Such interactions are not present in the centrosymmetric trans isomer.
authors.affiliation: Instituto de Física, Universidad Autónoma de Puebla, Av. San Claudio y 18 Sur, 72570 Puebla, Pue., Mexico.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bernès
authors.affiliation: Laboratorio de Química Teórica, Facultad de Ciencias Químicas, Universidad Autónoma de Puebla, Edif. 105-I, Ciudad Universitaria, 72570 Puebla, Pue., Mexico.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Meléndez
authors.affiliation: Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México DF, Mexico.
authors.forename: Hugo
authors.initials: H
authors.lastname: Torrens
keywords: NBO analysis; agostic bond; computational chemistry; crystal structure; fluorinated ligands; geometric isomer; phosphane; platinum