Influence of the R-substituents on the properties of [Ni(R2pipdt)(dmit)] complexes and crystal structure where R = CH2C6H5
作者:Elaine A. M. Geary、Lesley J. Yellowlees、Simon Parsons、Luca Pilia、Angela Serpe、M. Laura Mercuri、Paola Deplano、Stewart J. Clark、Neil Robertson
DOI:10.1039/b712243h
日期:——
the R2pipdt part of the complex. Accordingly the low frequency absorption, assigned to the HOMO-LUMO transition which has inter-ligand charge-transfer character, is found for 1b at lower frequency when compared to the corresponding transition of 2b. In situ EPR was carried out on electroreduced radical species of the R2pipdt ligand precursors (1a, 2a ) and corresponding complexes (1b, 2b ). This revealed
[Ni(R2pipdt)(dmit)],(R2pipdt = 1,4-二取代-哌嗪-3,2-二硫酮,R = CH2C6H5; dmit = 1,3-二硫代-2-硫酮-4,5-二硫代磺酸盐)(已经制备和表征了1b),并与属于相同类别的已知配合物2b的性质进行了比较,其中R = Pr i。进行1b和2b的循环伏安法,并将其与相应的R2pipdt配体前体(1a和2a)的伏安法进行比较。pipdt配体的R-基团的性质对氧化还原电势产生影响,并确认LUMO的位置主要位于络合物的R2pipdt部分。因此,与2b的相应跃迁相比,在较低的频率下发现了1b的低频吸收,该低频吸收被分配给具有配体间电荷转移特性的HOMO-LUMO跃迁。对R2pipdt配体前体(1a,2a)和相应的配合物(1b,2b)的电还原自由基进行原位EPR。这表明1b和2b中R2pipdt配体上未成对的电子有相当大的离域,与N和H的偶合常