O,N-Coordinated o-iminobenzoquinone and o-iminobenzosemiquinonato(1–) ligands in complexes of Ni(ii), Co(iii) and Fe(iii)
作者:Kil Sik Min、Thomas Weyhermüller、Karl Wieghardt
DOI:10.1039/b211698g
日期:2003.3.12
Octahedral complexes of the type [M(tren)(LIBQ)]n+ or [M(tren)(LISQ)]n+
(tren = tris(2-aminoethyl)amine; LIBQ
=
o-iminobenzoquinone, (LISQ)1â
=
o-iminobenzosemiquinonate(1â)
Ï radical, M = Ni, Co, Fe) have been prepared by the reaction of equimolar amounts of 2-anilino-4,6-di-tert-butylphenol, tris(2-aminoethyl)amine, M(CH3CO2)2·4H2O (M = Ni, Co) or FeCl2·4H2O in CH3OH containing 2 equivalents of NEt3 and air. The following complexes were isolated and characterized by X-ray crystallography: redâblack [NiII(tren)(LIBQ)](PF6)2
(1), green [NiII(tren)(LISQ)](ClO4)
(2), brown [CoIII(tren)(LISQ)](ClO4)2·0.5CH3OH·0.5H2O (3), [FeIII(tren)(LISQ)](ClO4)2·0.5CH3OH·0.5H2O (4). Their electrochemistry has been studied and the oxidized and reduced species have been characterized by UV-vis, EPR and Mössbauer spectroscopy. Temperature-dependent magnetic susceptibility measurements (2â290 K) reveal that 1 possesses an S
= 1, 2 an S
= 3/2, 3 an S
=
½, and 4 an S
= 0 ground state. The metrical details of O,N-coordinated (LAP-H)2â, (LISQ)1âË, and (LIBQ)0 ligands are clearly established. (LAP-H)2â represents the aromatic dianion o-iminophenolate.
类型为[M(tren)(LIBQ)]n+或[M(tren)(LISQ)]n+的八面体配合物(tren = 三(2-氨基ethyl)胺;LIBQ = o-亚氨基苯醌,(LISQ)1− = o-亚氨基苯半醌阴离子(1−)π自由基,M = Ni,Co,Fe)是通过将摩尔相等的2-苯胺-4,6-二叔丁基苯酚、三(2-氨基ethyl)胺、M(CH3CO2)2·4H2O(M = Ni,Co)或FeCl2·4H2O在包含2当量NEt3和空气的甲醇中反应制备的。以下配合物被分离并通过X射线晶体学鉴定:红-黑[NiII(tren)(LIBQ)](PF6)2(1),绿色[NiII(tren)(LISQ)](ClO4)(2),褐色[CoIII(tren)(LISQ)](ClO4)2·0.5CH3OH·0.5H2O(3),[FeIII(tren)(LISQ)](ClO4)2·0.5CH3OH·0.5H2O(4)。它们的电化学已被研究,氧化和还原物种通过紫外-可见光、EPR和莫斯堡光谱学进行了表征。温度依赖性磁化率测量(2–290 K)显示,1具有S = 1,2具有S = 3/2,3具有S = 1/2,而4具有S = 0的基态。O,N协调的(LAP-H)2−、(LISQ)1−·和(LIBQ)0配体的测量细节得到了明确的确立。(LAP-H)2−代表芳香族二阴离子o-亚氨基苯酚。