Nieto Ismael, Ding Feizhi, Bontchev Ranko P, Wang Haobin, Smith Jeremy M
Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces New Mexico 88003, USA.
J Am Chem Soc. 2008 Mar 5;130(9):2716-7. doi: 10.1021/ja0776834. Epub 2008 Feb 12.
Thermodynamic investigations relevant to hydrogen atom transfer by the high-valent iron imido complex [LMesFe[triple bond]NAd]OTf have been undertaken. The complex is found to be weakly oxidizing by cyclic voltammetry (E1/2 = -0.98 V vs Cp2Fe+/Cp2Fe in MeCN). A combination of experimental and computational studies has been used to determine the acidity of LMesFe-N(H)Ad+ (pKa = 37 in MeCN), allowing the N-H BDFE (88(5) kcal/mol) to be calculated from a thermodynamic cycle. Consistent with this value, [LMesFe[triple bond]NAd]OTf reacts with 9,10-dihydroanthracene (C-H BDE = 78(1) kcal/mol) to form anthracene.
已经开展了与高价铁亚胺配合物[LMesFe≡NAd]OTf的氢原子转移相关的热力学研究。通过循环伏安法发现该配合物具有弱氧化性（在乙腈中，相对于Cp2Fe⁺/Cp2Fe，E1/2 = -0.98 V）。实验和计算研究相结合，用于确定LMesFe-N(H)Ad⁺的酸度（在乙腈中pKa = 37），从而可以通过热力学循环计算N-H键解离能（BDFE）（88(5) kcal/mol）。与该值一致，[LMesFe≡NAd]OTf与9,10-二氢蒽（C-H键解离能 = 78(1) kcal/mol）反应生成蒽。
