Bis-phosphonio-isophosphindolide Copper Complexes
Bis-phosphonio-isophosphindolide Copper Complexes
复制标题
双膦酰基异膦酰内酯铜配合物
DOI：
10.1515/znb-1999-1005
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
M. Schrott
中科院分区：
文献类型：
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作者：
D. Gudat;Andreas W. Holderberg;N. Korber;M. Nieger;M. Schrott
双三苯基膦基异膦吲哚盐1[X]与铜(I)卤化物Cux反应，得到可分离的化合物[(1)Cu2X3]。X-射线晶体结构分析证实，对于X=BrClCu2X2双核配合物[(μ-1)(μ-X)Cu2X2]与μ2形成了η1(P)桥联阳离子1，而对于X=I，得到了含有盐(1)2[Cu4I6]和末端η1(P)配位配体1的配合物[(1)2Cu4I6]的固相.两种类型的络合物的成键参数表明，L I S是一种磷阳离子和磷脂阴离子的混合体，其π-体系的亲核性低于磷单对。31P核磁共振研究表明，在所有情况下，双核配合物[(1)Cu2X3]在溶液中处于动态平衡状态，只有少量的单核物种和游离的1。在体系1[OTf]/CuOTf中也检测到了同样的平衡。配体交换反应的核磁共振研究表明，络合物[(1)Cu2X3]的稳定性按X=OTf<；i<；bR，Cl的顺序增加，并允许[(1)Cu2Br3]与Et4NBr滴定以确定络合物形成反应的平衡常数。
Bis-triphenylphosphonio-isophosphindolide salts 1[X] react with Cu(I)-halides CuX to give isolable products of composition [(1)Cu2X3 ]. X-ray crystal structure analyses confirmed that for X = Br, Cl dinuclear complexes [(μ-1 )(μ-X)Cu2X2] with μ2, η1(P)-bridging cations 1 are formed, while for X = I a solid phase containing a salt (1)2[Cu4I6] and a complex [(1)2Cu4I6] with a terminal η1(P)-coordinated ligand 1 was obtained. The bonding parameters in the two types of complexes suggest that l i s a hybrid between a phosphenium cation and a phospholide anion whose π-system is less nucleophilic than the phosphorus lone-pair.31P NMR studies revealed that in solution in all cases binuclear complexes [(1)Cu2X3] are in dynamic equilibrium with small amounts of mononuclear species and free 1. The same equilibria were detected in the system 1[OTf]/CuOTf. NMR studies of ligand exchange reactions indicated that the stability of complexes [(1)Cu2X3 ] increases in the order X = OTf < I < Br, Cl, and titration of [(1)Cu2Br3] with Et4NBr allowed to determine the equilibrium constant of the complex formation reaction.