作者:Charles L. Perrin、Yeong-Joon Kim
DOI:10.1021/ic000382+
日期:2000.8.1
Is a metal chelate symmetric, with the motion of the metal described by a single-well potential, or is it asymmetric, in a double-well potential? For hydrogen, this is the familiar question of the symmetry of a hydrogen bond. The molecular symmetry of MLn complexes (M = Li, Na, K, Al, Pd, Rh, Si, Sn, Ge, Sb, etc.; L is the anion of 3-hydroxy-2-phenylpropenal) in solution is now probed with the method
金属螯合物是对称的,金属的运动是由单阱势描述的还是非对称的?对于氢,这是氢键对称性的常见问题。现在检测溶液中MLn配合物的分子对称性(M = Li,Na,K,Al,Pd,Rh,Si,Sn,Ge,Sb等; L是3-羟基-2-苯基丙烯醛的阴离子)用同位素摄动平衡的方法。合成了3-羟基-2-苯基丙烯醛-d0,-1-d和-1,3-d2的统计混合物,并将其转化为各种金属络合物。一些配合物显示两个醛信号,这意味着它们的配体是单齿的。对于LiL,NaL和KL,醛CH基的13C NMR同位素位移δCH(D)-δCH(H)小且为负,与L-是共振杂化体一致。它们很小,对AlL3,PdL2,Rh(CO)2L,SiX3L,SiL3 + X-,(CF3)3GeL,SbCl4L,(EtO)4TaL和(EtO)4NbL都是正的。正同位素位移是不寻常的,但是由于它们很小且与温度无关,因此它们是固有的,表明这些金属螯合物是