Chan Siu-Chung, Gupta Puneet, Engelmann Xenia, Ang Zhi Zhong, Ganguly Rakesh, Bill Eckhard, Ray Kallol, Ye Shengfa, England Jason
Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Max-Plank-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany.
Angew Chem Int Ed Engl. 2018 Nov 26;57(48):15717-15722. doi: 10.1002/anie.201809158. Epub 2018 Nov 2.
To probe the possibility that carbodicarbenes (CDCs) are redox active ligands, all four members of the redox series [Fe(1) ] (n=2-5) were synthesized, where 1 is a neutral tridentate CDC. Through a combination of spectroscopy and DFT calculations, the electronic structure of the pentacation is shown to be [Fe (1 ) ] (S= ). That of [Fe(1) ] is more ambiguous, but it has significant contributions from the open-shell singlet [Fe (1)(1 )] (S=0). The observed spin states derive from antiferromagnetic coupling of their constituent low-spin iron(III) centres and cation radical ligands. This marks the first time redox activity has been observed for carbones and expands the diverse chemical behaviour known for these ligands.
为探究碳二亚甲基卡宾（CDCs）作为氧化还原活性配体的可能性，合成了氧化还原系列[Fe(1) ]的所有四个成员（n = 2 - 5），其中1是中性三齿CDC。通过光谱学和密度泛函理论（DFT）计算相结合的方法，五价阳离子的电子结构显示为[Fe (1 ) ]（S = ）。[Fe(1) ]的电子结构则更为模糊，但开壳单重态[Fe (1)(1 )]（S = 0）对其有显著贡献。观察到的自旋态源自其组成的低自旋铁（III）中心和阳离子自由基配体的反铁磁耦合。这标志着首次观察到碳烯具有氧化还原活性，并扩展了这些配体已知的多样化学行为。
