Synthesis and Characterization of Cobalt(II) N,N′-Diphenylazodioxide Complexes

Abstract

Removal of chloride from CoCl 2 with TlPF 6 in acetonitrile, followed by addition of excess nitrosobenzene, yielded the eight-coordinate cobalt(II) complex salt [Co{Ph(O)NN(O)Ph} 4 ](PF 6 ) 2 , shown by single-crystal X-ray analysis to have a distorted tetragonal geometry. The analogous treatment of the bipyridyl complex Co(bpy)Cl 2 yielded the mixed-ligand cobalt(II) complex salt [Co(bpy){Ph(O)NN(O)Ph} 2 ](PF 6 ) 2 , whose single-crystal X-ray structure displays a trigonal prismatic geometry, similar to that of the iron(II) cation in the previously known complex salt [Fe{Ph(O)NN(O)Ph} 3 ](FeCl 4 ) 2 . The use of TlPF 6 to generate solvated metal complex cations from chloride salts or chlorido complexes, followed by the addition of nitrosobenzene, is shown to be a useful synthetic strategy for the preparation of azodioxide complex cations with the noncoordinating, diamagnetic PF 6 – counteranion. Coordination number appears to be more important than d electron count in determining the geometry and metal–ligand bond distances of diphenylazodioxide complexes.

Cobalt(II) Diphenylazodioxide Complexes Induce Apoptosis in SK-HEP-1 Cells

“…Compounds 1 and 2 , Co(bpy)Cl 2 were prepared as previously described by the Boyd group. 24 Co(phen)Cl 2 was prepared as described by Nami and Siddiqi. 32 Antibodies to PARP, procaspase-8, cleaved caspase-8, procaspase-9, cleaved caspase-9, Bim, Bcl-2, and BAD were obtained from Cell Signaling Technology, Inc. (Danvers, MA).…”

“…The cells were kept in a humidified atmosphere with 5% CO 2 at 37 °C. When the cell confluence reached 70%, the cells were treated with or without compound 1 or 2 at different concentrations (0, 1, 2, 5, or 10 μM) for a given amount of time (1,6,12,24, or 36 h). Compounds 1 and 2 were dissolved in DMSO before being diluted in the aqueous solution.…”

“…Compounds 1 and 2 , Co­(bpy)­Cl 2 were prepared as previously described by the Boyd group . Co­(phen)­Cl 2 was prepared as described by Nami and Siddiqi .…”

“…Recently, one of our groups has prepared two novel Co­(II) complexes of the unusual ligand cis - N , N ′-diphenylazodioxide (az): the six-coordinate, trigonal prismatic complex salt [Co­(bpy)­(az) 2 ]­(PF 6 ) 2 , where bpy = 2,2′-bipyridyl (compound 1 ), and the eight-coordinate, tetragonal complex salt [Co­(az) 4 ]­(PF 6 ) 2 (compound 2 ), both high-spin with three unpaired electrons per complex cation . The structures of 1 and 2 are shown in Scheme .…”

Coordination Polymer of Cobalt (ΙΙ) Nitrate with Imidazole: Synthesis, Properties and Crystal Structure

“…X-ray structural analysis of the crystal was carried out at a temperature of 100 K on a Bruker Quest D8 diffractometer equipped with a Photon-ΙΙΙ detector and a water-cooled X-ray tube (30 mA, 50 kB, λ (MoKα) = 0.71073 Ǻ, graphite monochromator, φand ω-scanning , step 0.35˚, exposure time 2 sec). Registration of reflections and establishment of the structure was carried out in the APEX software [8] package ΙΙΙ. The reflection intensities were integrated using the SAINT program [9].…”