School of Chemical Sciences, Goa University, Goa-403206, India.
Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India.
Dalton Trans. 2021 Mar 2;50(8):2824-2831. doi: 10.1039/d0dt03706k.
A mononuclear manganese(iii)-peroxo complex [MnIII(N3Py2)(O2)]+ (1a) bearing a non-heme N,N'-dimethyl-N-(2-(methyl(pyridin-2-ylmethyl)amino)ethyl)-N'-(pyridin-2-ylmethyl)ethane-1,2-diamine (N3Py2) ligand was synthesized by the reaction of Mn(N3Py2)(H2O)2 (1) with hydrogen peroxide and triethylamine in CH3CN at 25 °C. The reactivity of 1a in aldehyde deformylation using 2-phenyl propionaldehyde (2-PPA) was studied and the reaction kinetics was monitored by UV-visible spectroscopy. A kinetic isotope effect (KIE) = 1.7 was obtained in the reaction of 1a with 2-PPA and α-[D1]-PPA, suggesting nucleophilic character of 1a. The activation parameters ΔH‡ and ΔS‡ were determined using the Eyring plot while Ea was obtained from the Arrhenius equation by performing the reaction between 288 and 303 K. Hammett constants (σp) of para-substituted benzaldehydes p-X-Ph-CHO (X = Cl, F, H, and Me) were linear with a slope (ρ) = 3.0. Computational study suggested that the side-on structure of 1a is more favored over the end-on structure and facilitates the reactivity of 1a.
单核锰(III)-过氧配合物[MnIII(N3Py2)(O2)]+（1a），其中含有非血红素 N,N'-二甲基-N-(2-(甲基(吡啶-2-基甲基)氨基)乙基)-N'-(吡啶-2-基甲基)乙二胺（N3Py2）配体，通过Mn(N3Py2)(H2O)2（1）与过氧化氢和三乙胺在 25°C 的 CH3CN 中的反应合成。研究了 1a 在使用 2-苯基丙醛（2-PPA）进行醛去甲酰化反应中的反应性，并通过紫外-可见光谱监测反应动力学。在 1a 与 2-PPA 和α-[D1]-PPA 的反应中获得了动力学同位素效应（KIE）= 1.7，表明 1a 的亲核性质。通过 Eyring 图确定了活化参数ΔH‡和ΔS‡，而通过在 288 和 303 K 之间进行反应，从 Arrhenius 方程获得了 Ea。对位取代苯甲醛 p-X-Ph-CHO（X = Cl、F、H 和 Me）的哈米特常数（σp）与斜率（ρ）= 3.0 呈线性关系。计算研究表明，1a 的侧式结构比端式结构更有利，并且有利于 1a 的反应性。
