π*-based lowest unoccupied molecular orbitals (LUMOs). In line with the unsymmetric character of the NPy^Nmethanimine ligand, electrochemistry and MLCT transitions seem to not correspond to the same type of π* LUMO, making these PyMA ligands more interesting than the symmetric heteroaromatic polypyridine ligands such as 2,2′-bipyridine (bpy; NPy^NPy) and N,N-diaryl-substituted aliphatic α-diimines (Nme
新的
有机镍配合物[(R-PyMA)Ni(Mes)X] [R-PyMA = N-芳基-1-(
吡啶-2-基)
甲胺; 芳基=苯基,2,6-Me 2-,3,5-Me 2-,2,4,6-Me 3-,2,6- i Pr 2-,3,5-(OMe)2-,2 -NO 2 -4-Me-,4-NO 2-,2-CF 3-和2-CF 3 -6-F-苯基;Mes = 2,4,6-三甲基苯基; X = F,Cl,Br或I]取决于PyMA
配体和X,以大约1/1的顺式和反式异构体混合物或纯顺式异构体形式获得。[(R-PyMA)Ni(Mes)X]配合物X = Br或Cl由前体反式-[(PPh 3)直接合成2个Ni(Mes)X],而X = F或I的[(PyMA)Ni(Mes)X]衍
生物是通过X交换反应从[(PyMA)Ni(Mes)Br]中获得的。尽管密度泛函理论(DFT)计算显示出偏爱于空间偏好的顺式异构体,但在许多情况下都可