TY - JOUR
T1 - Synthesis and electrochemical studies of octahedral nickel β-diketonate complexes
AU - Harding, Phimphaka
AU - Harding, David J
AU - Phonsri, Wasinee
AU - Saithong, Saowanit
AU - Phetmung, Hirihattaya
PY - 2009/1/1
Y1 - 2009/1/1
N2 - The reaction of [Ni(tmhd)2] and [Ni(dbm)2] with N-donor chelating ligands in dichloromethane and acetone, respectively, yields the complexes [Ni(tmhd)2(L-L)] (L-L = 2,2′-bpy 1, phen 2 and dmae 3) and [Ni(dbm)2(L-L)] (L-L = 2,2′-bpy 4, phen 5, dmae 6). UV-Vis spectroscopy shows very strong bands in the UV region consistent with ligand centred π → π* transitions. The electrochemical studies of 1-6 reveal oxidation to Ni(III). The [Ni(tmhd)2(L-L)] 1-3 are more easily oxidized by ca. 300 mV and are quasi-reversible whereas for the [Ni(dbm)2(L-L)] series only complex 6 shows significant reversibility. X-ray crystallographic studies have been conducted in the case of [Ni(dbm)2(phen)] 5 and [Ni(dbm)2(dmae)] 6. The structures both show that the nickel metal centre is octahedral with an O4N2 coordination environment. In the structures the β-diketonate ligands exhibit a cis-arrangement, with the metal displaced out of the planar chelate ring.
AB - The reaction of [Ni(tmhd)2] and [Ni(dbm)2] with N-donor chelating ligands in dichloromethane and acetone, respectively, yields the complexes [Ni(tmhd)2(L-L)] (L-L = 2,2′-bpy 1, phen 2 and dmae 3) and [Ni(dbm)2(L-L)] (L-L = 2,2′-bpy 4, phen 5, dmae 6). UV-Vis spectroscopy shows very strong bands in the UV region consistent with ligand centred π → π* transitions. The electrochemical studies of 1-6 reveal oxidation to Ni(III). The [Ni(tmhd)2(L-L)] 1-3 are more easily oxidized by ca. 300 mV and are quasi-reversible whereas for the [Ni(dbm)2(L-L)] series only complex 6 shows significant reversibility. X-ray crystallographic studies have been conducted in the case of [Ni(dbm)2(phen)] 5 and [Ni(dbm)2(dmae)] 6. The structures both show that the nickel metal centre is octahedral with an O4N2 coordination environment. In the structures the β-diketonate ligands exhibit a cis-arrangement, with the metal displaced out of the planar chelate ring.
KW - β-Diketonates
KW - Crystal structure
KW - Cyclic voltammetry
KW - Ni(II) and Ni(III)
KW - Octahedral
UR - http://www.scopus.com/inward/record.url?scp=56649109913&partnerID=8YFLogxK
U2 - 10.1016/j.ica.2008.03.014
DO - 10.1016/j.ica.2008.03.014
M3 - Article
AN - SCOPUS:56649109913
SN - 0020-1693
VL - 362
SP - 78
EP - 82
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 1
ER -