title: Pyridazine based scorpionate ligand in a copper boratrane compound.
abstract: Reaction of potassium tris(mercapto-tert-butylpyridazinyl)borate K[Tn(tBu)] with copper(II) chloride in dichloromethane at room temperature led to the diamagnetic copper boratrane compound [Cu{B(Pn(tBu))(3)}Cl] (Pn = pyridazine-3-thionyl) (1) under activation of the B-H bond and formation of a Cu-B dative bond. In contrast to this, stirring of the same ligand with copper(I) chloride in tetrahydrofuran (THF) gave the dimeric compound [Cu{Tn(tBu)}](2) (2) where one copper atom is coordinated by two sulfur atoms and one hydrogen atom of one ligand and one sulfur of the other ligand. Hereby, no activation of the B-H bond occurred but a 3-center-2-electron B-H···Cu bond is formed. The reaction of copper(II) chloride with K[Tn(tBu)] in water gave the same product 2, but a formal reduction of the metal center from Cu(II) to Cu(I) occurred. When adding tricyclohexyl phosphine to the reaction mixture of K[Tn(R)] (R = tBu, Me) and copper(I) chloride in MeOH, the distorted tetrahedral Cu complexes [Cu{Tn(R)}(PCy(3))] (R = tBu 3, Me 4) were formed. Compound 4 is exhibiting an "inverted" κ(3)-H,S,S, coordination mode. The copper boratrane 1 was further investigated by density functional theory (DFT) calculations for a better understanding of the M→B interaction involving the d(8) electron configuration of Cu.
authors.affiliation: Institut für Chemie, Karl-Franzens-Universität Graz, Schubertstrasse 1, A-8010 Graz, Austria.
authors.forename: Gernot
authors.initials: G
authors.lastname: Nuss
authors.forename: Gerald
authors.initials: G
authors.lastname: Saischek
authors.forename: Bastian N
authors.initials: BN
authors.lastname: Harum
authors.forename: Manuel
authors.initials: M
authors.lastname: Volpe
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Belaj
authors.forename: Nadia C
authors.initials: NC
authors.lastname: Mösch-Zanetti
mesh_terms: D001881:Borates / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D005663:Furans / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D000432:Methanol / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010720:Phosphines / Q000737:chemistry; D011724:Pyridazines / Q000737:chemistry*; D011789:Quantum Theory; D013455:Sulfur / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D001881:Borates; D056831:Coordination Complexes; D005663:Furans; D008024:Ligands; D010720:Phosphines; D011724:Pyridazines; D014867:Water; C018674:tetrahydrofuran; C062482:pyridazine; D008752:Methylene Chloride; D013455:Sulfur; D003300:Copper; D000432:Methanol