作者:F. Albert Cotton、Lee M. Daniels、Carlos A. Murillo、Paul Schooler
DOI:10.1039/b000329h
日期:——
A study regarding the interaction of several ortho ring-substituted N,Nâ²-diarylformamidinate ligands (DPhXF, X = Me, OMe, Cl and Br) with the Cr24+ moiety has been undertaken. X-Ray diffraction and spectroscopic data have shown that while all of these ligands form the well-known paddlewheel type complex Cr2(DPhXF)4, 1 [X = Me, OMe, Cl and Br; CrâCr = 1.925(1), 2.140(2), 2.208(2) and 2.272(2) Ã
, respectively], two of them form highly unusual A-frame type complexes with short CrâCr bonds, and the smallest MâXâM angle ever reported in an A-frame structure. These are Cr2(μ-Cl)(DPhXF)3, 2 [X = Cl and Br; CrâCr = 1.940(1) and 1.940(2) Ã
, respectively]. For some of the paddlewheel complexes, the elongation of the metalâmetal bond distance out of the âsuper-shortâ range (CrâCr > 2.00 Ã
) has been attributed to the presence of axial interactions between two of the ortho substituents and the Cr24+ moiety.
一项关于几种邻位环取代的N,Nʹ-二芳基甲酰胺配体(DPhXF,X = Me、OMe、Cl和Br)与Cr²⁺部分相互作用的研究已经展开。X射线衍射和光谱数据表明,虽然这些配体均形成了著名的桨轮型复合物Cr₂(DPhXF)₄, 1 [X = Me、OMe、Cl和Br; Cr–Cr分别为1.925(1)、2.140(2)、2.208(2)和2.272(2) Å],但其中两个配体形成了具有短Cr–Cr键的相当不寻常的A型架构复合物,并且是迄今报道中A型结构中最小的M–X–M角。这些复合物为Cr₂(μ-Cl)(DPhXF)₃, 2 [X = Cl和Br; Cr–Cr分别为1.940(1)和1.940(2) Å]。对于某些桨轮型复合物,金属–金属键距的延长超出“超短”范围(Cr–Cr > 2.00 Å)被归因于两个邻位取代基与Cr²⁺部分之间的轴向相互作用。