title: Kit for unsymmetric dinucleating double-Schiff-base ligands: facile access to a versatile new ligand system and its first heterobimetallic copper-zinc complex.
abstract: The synthetic route toward new unsymmetric compartmental "end-off" Schiff-base ligands in a straightforward two-step reaction of 2,6-diformyl-4-methylphenol and two different amine components is presented. To demonstrate the versatility of this method, we have synthesized two different single-Schiff-base proligands, Hbpahmb and Hphmb, utilizing (2-aminoethyl)bis(2-pyridylmethyl)amine and (2-aminomethyl)pyridine, respectively. Subsequent reaction with thiosemicarbazide as the second amine component leads to the novel unsymmetric double-Schiff-base ligands {1-[3-[2-[bis(pyridin-2-ylmethyl)amino]ethyliminomethyl]-2-hydroxy-5-methylphenyl]methylidene}hydrazine carbothioamide (H2bpamptsc) and {1-[3-(pyridin-2-ylmethyliminomethyl)-2-hydroxy-5-methylphenyl]methylidene}hydrazine carbothioamide (H2pmptsc). Both ligands provide two distinctly different coordination pockets: a rigid tridentate N,O,S donor set of the hydrazide compartment versus a rather flexible pentadentate (H2bpamptsc) or tridentate (H2pmptsc) nitrogen-rich chelating side arm. The reaction of the ligand H2bpamptsc with zinc(II) acetate and copper(II) perchlorate yields the heterobinuclear Cu-Zn complex [CuZn(bpamptsc)(mu2,eta1-OAc)(MeCN)](ClO4) (1).
authors.affiliation: Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Carl-Zeiss-Promenade 10, D-07745 Jena, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Roth
authors.forename: Eike T
authors.initials: ET
authors.lastname: Spielberg
authors.forename: Winfried
authors.initials: W
authors.lastname: Plass
mesh_terms: D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D012545:Schiff Bases / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
chemical_list: D008024:Ligands; D012545:Schiff Bases; D003300:Copper; D015032:Zinc