Novel Phenanthroline Ligands and Their Kinetically Locked Copper(I) Complexes with Unexpected Photophysical Properties
作者:Venkateshwarlu Kalsani、Michael Schmittel、Andrea Listorti、Gianluca Accorsi、Nicola Armaroli
DOI:10.1021/ic051828v
日期:2006.3.1
formation of the homoleptic complex [Cu(1a)2]+ becomes very slow (5 days). Once formed, the homoleptic complexes [Cu(1a,b)2]+ do not exchange ligands even with phen added in excess because they are kinetically locked due to the large tert-butylphenyl substituents at the phenanthroline unit. The electronic absorption spectra of the homoleptic complexes [Cu(1a)2]+ and [Cu(1b)2]+ evidence a strongly different
新的,空间受限的菲咯啉配体1a,b均以在2,9位上存在庞大的芳基取代基(3,5-二叔丁基-4-甲氧基苯基,2,4,6-三甲基苯基)为特征,与它们的同型[Cu(1a,b)2] +和杂型配合物[Cu(1a,b)(phen)] +(phen =母体1,10-菲咯啉)一起制备。由于明显的空间屏蔽作用,特别是在配体1a中特别有效,因此均纯络合物[Cu(1a)2] +的形成变得非常缓慢(5天)。一旦形成,均聚物络合物[Cu(1a,b)2] +甚至不会添加过量的phen也不会交换配体,因为它们由于菲咯啉单元上的大叔丁基苯基取代基而被动力学锁定。均质络合物[Cu(1a)2] +和[Cu(1b)2] +的电子吸收光谱表明,这两种化合物的基态几何形状有很大不同,前者的扭曲程度更大。从发射光谱和CH2Cl2溶液的寿命得出的激发态几何形状中也观察到了这种趋势。与[Cu(1a)2] +相比,失真较小的[Cu(1b)2]