TY - JOUR AU - Kaim, Wolfgang AU - Titze, Christoph AU - Schurr, Thilo AU - Sieger, Monika AU - Lawson Daku, Latévi Max AU - Jordanov, Jeanne AU - Rojas, Darío AU - García, Ana M. AU - Manzur, Jorge TI - Reactivity of Copper(I) Complexes with Tripodal Ligands towards O2: Structures of a Precursor [L3CuI(NCCH3)](BF4), L3 = Tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane and of its Oxidation Product [L3CuII(-OH)2CuIIL3](BF4)2 with Strong Antiferromagnetic Spin-Spin Coupling PY - 2005 JF - Zeitschrift für anorganische und allgemeine Chemie JA - Z. anorg. allg. Chem. SN - 0044-2313 VL - 631 IS - 13-14 SP - 2568 EP - 2574 L1 - http://www3.interscience.wiley.com/cgi-bin/fulltext/112126775/PDFSTART L3 - http://www3.interscience.wiley.com/cgi-bin/abstract/112126775/ABSTRACT M3 - 10.1002/zaac.200500053 UR - http://dx.doi.org/10.1002/zaac.200500053 N2 - The molecular structure of the highly oxygen-sensitive complex [L3CuI(NCCH3)](BF4) (1) reveals approximately symmetrical coordination by the fac-tridentate (tripodal) ligand L3 = tris(3-isopropyl-4,5-trimethylenepyrazolyl)methane and a rather short CuI-N(acetonitrile) distance of 1.865(5) Å. In CH2Cl2 at -78 °C the colourless compound reacts with O2 to yield a labile purple intermediate (λmax 517 nm) - presumably a peroxodicopper(II) complex - which decomposes at -30 °C. No such intermediate was observed on reaction of the CuI complex of bis(2-pyridylmethyl)benzylamine with O2 at -80 °C. However, an EPR spectrum with g|| = 2.17 and g_|_ = 2.03 without 63,65Cu hyperfine splitting was observed at low temperatures. Exposure of the precursor 1 to air under ambient conditions yields dinuclear [L3Cu||(μ-OH)2CuIIL3](BF4)2 (2) which exhibits an EPR detectable dissociation into monomers in CH2Cl2 solution. The structure of the hexakis(dichloromethane) solvate of 2 with Cu-Cu and Cu-O distances of 3.055 and 1.94Å, respectively, is typical for dihydroxo-bridged dicopper compounds with square-pyramidal Cu|| configuration (τ = 0.03), adopting an anti arrangement. In agreement with the relatively wide Cu-O-Cu angles of 103.5° an analysis of the temperature dependence of the magnetic susceptibility revealed a rather strong (J = -633 cm-1) antiparallel spin-spin coupling. The effect is ascribed to the steric bulk of the ligand L3. ID - 865 ER -