title: Tricarbonylrhenium(I) complexes with thiosemicarbazone derivatives of 2-acetylpyridine and 2-pyridine formamide showing two unusual coordination modes of tridentate thiosemicarbazone ligands.
abstract: [NEt(4)](2)[Re(CO)(3)Br(3)] reacts with 2-acetylpyridine phenylthiosemicarbazone (HL(1)) and 2-pyridine formamide thiosemicarbazone (HL(2)) under formation of air-stable, neutral rhenium(I) complexes of the compositions [Re(CO)(3)(L(1)-N,N,S)] and [Re(CO)(3)Br(HL(2)-N,N)]. Spectroscopic studies and X-ray crystallography show that the potentially tridentate thiosemicarbazones adopt unusual coordination modes. Whereas HL(1) deprotonates and binds to the metal in a nonplanar fashion, HL(2) acts as neutral N,N donor ligand. The bond lengths inside the chelate rings are almost uninfluenced by the overall bonding situation.
authors.affiliation: Institute of Chemistry, Freie Universität Berlin, Fabeckstrasse 34-36, D-14195 Berlin, Germany.
authors.forename: Isabel Garcia
authors.initials: IG
authors.lastname: Santos
authors.forename: Ulrich
authors.initials: U
authors.lastname: Abram
authors.forename: Roger
authors.initials: R
authors.lastname: Alberto
authors.forename: Ezequiel Vazquez
authors.initials: EV
authors.lastname: Lopez
authors.forename: Agustin
authors.initials: A
authors.lastname: Sanchez