Reactivity of Nitric Oxide and Nitrosonium Ion with Copper(II/I) Schiff Base Complexes: Mechanistic Aspects of Imine C═N Bond Cleavage and Oxidation of Pyridine-2-aldehyde to Pyridine-2-carboxylic Acid
作者:Saikat Mishra、Shibaditya Kumar、Anirban Bhandari、Aniruddha Das、Pallav Mondal、Geeta Hundal、Marilyn M. Olmstead、Apurba K. Patra
DOI:10.1021/acs.inorgchem.1c04038
日期:2022.5.2
aid of NO+ oxidant, the picolinate-ligated copper(II) complexes (i) [(HPic)2Cu] (7), [(MePic)4Cu3(NO3)2]n·H2O (8·H2O), or [(ClPhPic)2Cu] (9) when NO reacts with 1–4 or (ii) [(RPic)CuII(RL1/RL2)]+ when NO+ reacts with 1′–4′. The CuII to CuI reduction of [(RPic)CuII(RL1/RL2)]+ is essential for C═N cleavage of the remaining RL1/RL2 Schiff base; excess NO can do it. The X-ray structures (1, 1′, 3′, 5,
通式 [6-( R )-2-吡啶基-N- (2'-甲基硫苯基)亚甲基亚胺] ( R L1) 和 6-对- 氯苯基-2-吡啶基- N - (2'-) 的四个席夫碱配体苯硫基苯基)亚甲基亚胺 ( R L2),其中 R = H、Me、p -ClPh,以及它们的双配体铜 (II) 和铜 (I) 配合物,分别为1 – 4和1' – 4',被合成并表征。1 – 4与一氧化氮 (NO) 气体的反应性以及1' – 4'与固体 NOBF 4 (NO +) 在存在和不存在水 (H 2 O) 的情况下在无水乙腈中进行检查。结果表明,在没有 H 2 O的情况下,配合物1 – 4(或1' – 4')与 NO(或 NOBF 4)反应,导致两个(或一个)席夫碱的亚胺 C=N 键断裂(s)通过 CuNO} 10型中间体的亚硝基铜生成 2(或 1)当量的 2-(甲基/苯基)硫代苯重氮高氯酸盐 ( 5 / 6 ) 和相应的吡啶甲醛