When Do Strongly Coupled Diradicals Show Strongly Coupled Reactivity? Thermodynamics and Kinetics of Hydrogen Atom Transfer Reactions of Palladium and Platinum Bis(iminosemiquinone) Complexes
作者:Kyle M. Conner、AnnaMaria C. Arostegui、Daniel D. Swanson、Seth N. Brown
DOI:10.1021/acs.inorgchem.8b00068
日期:2018.8.20
with suitably substituted hydrazobenzenes, and the palladium bis(iminosemiquinone) is markedly more oxidizing than the platinum compound, with hydrogen transfer from (tBuClipH2)Pt to (tBuClip)Pd occurring with ΔG° = −8.9 kcal mol–1. The palladium complex (tBuClipH2)Pd reacts with nitroxyl radicals in two observable steps, with the first hydrogen transfer taking place slightly faster than the second. In
2,2'-亚联苯基-桥连的双(iminosemiquinone)络合物(吨BuClip)M [吨BuClipH 4 = 4,4'-二-叔丁基- Ñ,Ñ ' -双(3,5-二-叔-丁基-2-羟基苯基)-2,2'-二氨基联苯; M = Pd,Pt]可通过与苯(M = Pd)反应或催化氢化(M = Pt)还原为双(氨基苯氧化物)配合物(t BuClipH 2)M。复合物与一个aminophenoxide配体和一种iminosemiquinone配体的钯,(吨BuClipH)的Pd,是由歧化生成(吨BuClip)的Pd与(吨BuClipH 2)Pd的过程既缓慢(在23°C下在甲苯中为0.06 M –1 s –1),又仅适度有利(在CDCl 3中为K com = 1.9 ),表明两个N–H键具有基本相同的键力量。没有观察到单(亚氨基醌)配合物(t BuClipH)Pt,表明铂类似物没有显示出相称的趋势(K