A mononuclear copper(I) complex with N-[(4-methyl-2-pyrimidinyl)methylene]-p-toluidine (1·BF4) and a dinuclear copper(I) complex with N,N′-bis[(4-methyl-2-pyrimidinyl)methylene]-p-phenylenediamine (2·(BF4)2) were synthesized as BF4− salts to evaluate the influence of the imine moiety on the pyrimidine ring rotation isomerism. 1·BF4 existed in solution as a mixture of two isomers; 2·(BF4)2 was present as a mixture of three isomers. The redox potentials of the copper centers were changed by pyrimidine ring rotation. Comparison of 1+ and 22+ indicated that increasing the steric congestion around the copper center increased the o/i isomer ratio; the redox potentials of both the o- and i-isomers shifted in the positive direction, and the CuII/I redox reaction became slower.
我们合成了 N-[(4-
甲基-2-
嘧啶基)亚
甲基]-对甲
苯胺(1-
BF4)的单核
铜(I)络合物和 N,N′-双[(4-
甲基-2-
嘧啶基)亚
甲基]-
对苯二胺(2-( )2)的双核
铜(I)络合物的 盐,以评估
亚胺分子对
嘧啶环旋转异构体的影响。1- 以两种异构体混合物的形式存在于溶液中;2-( )2 则以三种异构体混合物的形式存在。
铜中心的
氧化还原电位因
嘧啶环的旋转而改变。对 1+ 和 22+ 的比较表明,增加
铜中心周围的立体拥塞会增加 o/i 异构体的比例;o 异构体和 i 异构体的
氧化还原电位都向正方向移动,CuII/I
氧化还原反应变得更慢。