Double Oxidative Dehalogenation of 2,5-Bis(diisopropylphosphoryl)-3,6-difluoro-1,4-hydroquinone leading to Formation of New Copper Quinonoid Complexes
Zeitschrift für anorganische und allgemeine Chemie, 2015, Volume 641, Issue 2, 414-420.
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Linked version is final published version.
Open air reactions of 2,5-bis(diisopropylphosphoryl)-3,6-difluoro-1,4-hydroquinone with (bipy)Cu(CH3COO)2 or (bipy)CuCl2 in wet methanol proceeded with oxidative dehalogenation of the ligand and the formation of bimetallic complexes supported by 2,5-bis(diisopropylphosphoryl)-3,6-dioxy-1,4-quinonate. The coordination mode of the bridging ligand towards (bipy)Cu(X) fragments depends on the nature of the anionic ligand (X = acetate or chloride). Thus, in bimetallic complex 2 [bis((2,2′-bipyridyl)copper(η2-acetate))-μ-(η2(O,O)-2,5-bis(diisopropylphosphoryl)-3,6-dioxy-1,4-quinonate] the ligand coordinates two (bipy)Cu(acetate) fragments into the [O,O] chelation pockets of the tetraoxolene core. In bimetallic complex 3 [bis((2,2′-bipyridyl)copper(chloride))-μ-(η2(O,(P=O))-2,5-bis(diisopropylphosphoryl)-3,6-dioxy-1,4-quinonate] the ligand coordinates the (bipy)CuCl fragments into its [O,(P=O)] pockets. Coordination chemistry was briefly explored by subjecting complex 3 to ligand-substitution reactions by reacting it with AgBF4 and with carboxylate and carbonate salts. Complexes 4 [bis((aqua)(dimethylformamide)(2,2′-bipyridyl)copper)-μ-(η2(O,(P=O))-2,5-bis(diisopropylphosphoryl)-3,6-dioxy-1,4-quinonate) di-tetrafluoroborate] and 5 [bis(aqua)(2,2'-bipyridyl)copper-(η2(O,O)-3,6-bis(diisopropylphosphoryl)-4,5-dioxy-1,2-quinonate] were obtained during these investigations. Compounds 2–5 were characterized by single-crystal X-ray diffraction, elemental analyses, and by spectroscopic and magnetic measurements.