镧系金属有机配合物Gd(2,4-C_7H_(11))_3的晶体和分子结构

CRYSTAL AND MOLECULAR STRUCTURE OF ORGANOLANTHANIDE COMPLEXGd(2,4-C_7H_(11))_3

2,4-二甲基戊二烯基的金属配合物在一些性质上可与相应的环戊二烯配合物相比拟。已报道了许多d过渡金属以及碱金属钾的配合物的晶体结构。对于镧系金属,仅Ernst等得到了2,4-二甲基戊二烯钕的配合物并测定了晶体结构,其晶格中含有无序的乙醚溶剂分子。本文报道了不含溶剂分子的Gd(2,4-C_7H_(11))_3,配合物在低温下的晶体结构。

The extremely air-sensitive complex Gd(2,4 - C7H11)3 has been prepared and its crystal structure has been determined at low temperature(-80℃). The crystal belongs to triclinic space group P1 with unit cell parameters a= 12.541(3), b = 12.853(3),c = 8.432(3) A,α=91.44(2), β= 108.61(2) γ=117.97(2)° and Z = 2. The final R value is 0.068. The Gd(Ⅲ) ion is coordinated by three 2,4-dimethylpentadienyl with average Gd-C(1),C(5),Gd-C(3) and Gd-C(2),C(4) bond distances of 2.738,2.755 and 2.821A,respectively. These distances indicate predominately ionic bonding. The 2,4-dimethylpentadienyl ligands have planar U conformation with the carbon atoms in the 1,3,5-positions bent in a direction toward the Gd(Ⅲ) ion and the carbons in the 2,4-positions bent in a direction away from the Gd(Ⅲ) ion, which shows negative charge localized somewhat more at 1,3,5-positions.