BINUCLEAR CHROMIUM(III) COMPLEXES BRIDGED BY HYDROXIDE AND ACETATE GROUPS
BINUCLEAR CHROMIUM(III) COMPLEXES BRIDGED BY HYDROXIDE AND ACETATE GROUPS
复制标题
由氢氧化物和乙酸酯基团桥联的双核铬(III)络合物
DOI：
10.1016/0020-1693(95)04827-8
复制
发表时间：
1996
影响因子：
2.8
通讯作者：
L. Spiccia
中科院分区：
文献类型：
--
作者：
S. J. Brudenell;S. Crimp;James K.E. Higgs;B. Moubaraki;K. Murray;L. Spiccia
合成了三种乙酰桥联双核铬(Ⅲ)配合物[(tren)Cr(μ-OH)(μ-O2CCH3)Cr(tren)](ClO4)4·4H2O(1)、[(trenH)Cr(μ-OH)(μ-O2CCH3)2Cr(trenH)](ClO4)5·6H2O(2)和[(H2O)4Cr(μ-OH)(μ-O2CCH3)Cr(OH2)4]((CH3)3C6H2SO3)4·8H2O(3)，并用一系列物理化学方法对其进行了表征。用单晶X射线衍射法测定了[(H2O)4Cr(μ-OH)(μ-O2CCH3)Cr(OH2)4]((CH3)3C6H2SO3)4·8H2O的晶体结构。该化合物属P21/c空间群，晶胞参数为a=18.350(4)，b=8.756(3)，c=36.373(6)，̊，β=98.54(2)°，Z=4。经最小二乘修正后，3,965次反射的R值和Rw值分别为0.122和0.126。该络合物由扭曲的八面体环境中的两个铬(III)中心组成，由一个乙酸酯和一个氢氧化桥连接在一起。The Cr…3.5 5(1)？由于乙酸桥联基团使铬-OH--铬角度变宽，使铬(Ⅲ)水解性二聚体中的铬距离较大。铬(Ⅲ)水溶液络合物中的铬-OH键长是典型的，而铬--OH和铬--O(醋酸酯)距离也在正常范围内。配合物1-3的磁化率与温度的关系表明，两个铬(Ⅲ)中心与−19.9、−15.7和−7.7 cm−1的耦合常数J分别为1、2和3的弱反铁磁耦合。
Three acetato-bridged binuclear Cr(III) complexes, [(tren)Cr(μ-OH)(μ-O2CCH3)Cr(tren)](ClO4)4·4H2O (1), [(trenH)Cr(μ-OH)(μ-O2CCH3)2Cr(trenH)](ClO4)5·6H2O (2) and [(H2O)4Cr(μ-OH)(μ-O2CCH3)Cr(OH2)4]((CH3)3C6H2SO3)4·8H2O (3), have been prepared and characterised using a range of physico-chemical techniques. The crystal structure of [(H2O)4Cr(μ-OH)(μ-O2CCH3)Cr(OH2)4]((CH3)3C6H2SO3)4·8H2O has been determined from single crystal X-ray diffraction studies. The compound crystallises in the space group P21/c, with a = 18.350(4), b = 8.756(3), c = 36.373(6) A ̊ , β = 98.54(2)° and Z = 4 . Least squares refinement gave R and Rwvalues of 0.122 and 0.126, respectively for 3965 observed reflections. The complex consists of two Cr(III) centres in a distorted octahedral environment held together by one acetate and one hydroxide bridge. The Cr…Cr distance of 3.55(1) Å is longer than in the Cr(III) hydrolytic dimer due to the widening of the CrOHCr angle caused by the bridging acetate group. The CrOH2bond lengths are typical of Cr(III) aqua complexes while the CrOH and CrO(acetate) distances are also in the normal range for such complexes. The temperature dependence of the magnetic susceptibility for complexes 1–3 indicates that the two Cr(III) centres are weakly antiferromagnetically coupled with coupling constants J of −19.9, −15.7 and −7.7 cm−1for 1, 2 and 3, respectively.