Ketimido Metallophthalocyanines: An Approach to Phthalocyanine‐Supported Mononuclear High‐Valent Ruthenium Complexes |
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| Authors: | Dr Jie‐Sheng Huang Dr Kwok‐Ming Wong Dr Sharon Lai‐Fung Chan Ken Chi‐Hang Tso Tao Jiang Prof?Dr Chi‐Ming Che |
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| Institution: | 1. Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road (Hong Kong), Fax: (+852)?2857‐1586;2. Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong), Fax: (+852)?2364‐9932 |
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| Abstract: | A “metal–ketimine+ArI(OR)2” approach has been developed for preparing metal–ketimido complexes, and ketimido ligands are found to stabilize high‐valent metallophthalocyanine (M? Pc) complexes such as ruthenium(IV) phthalocyanines. Treatment of bis(ketimine) ruthenium(II) phthalocyanines RuII(Pc)(HN?CPh2)2] ( 1a ) and RuII(Pc)(HNQu)2] ( 1b ; HNQu=N‐phenyl‐1,4‐benzoquinonediimine) with PhI(OAc)2 affords bis(ketimido) ruthenium(IV) phthalocyanines RuIV(Pc)(N?CPh2)2] ( 2a ) and RuIV(Pc)(NQu)2] ( 2b ), respectively. X‐ray crystal structures of 1b and RuII(Pc)(PhN?CHPh)2] ( 1c ) show Ru? N(ketimine) distances of 2.075(4) and 2.115(3) Å, respectively. Complexes 2a , 2b readily revert to 1a , 1b upon treatment with phenols. 1H NMR spectroscopy reveals that 2a , 2b are diamagnetic and 2b exists as two isomers, consistent with a proposed eclipsed orientation of the ketimido ligands in these ruthenium(IV) complexes. The reaction of 1a , 1b with PhI(OAc)2 to afford 2a , 2b suggests the utility of ArI(OR)2 as an oxidative deprotonation agent for the generation of high‐valent metal complexes featuring M? N bonds with multiple bonding characters. DFT and time‐dependent (TD)‐DFT calculations have been performed on the electronic structures and the UV/Vis absorption spectra of 1b and 2b , which provide support for the diamagnetic nature of 2b and reveal a significant barrier for rotation of the ketimido group about the Ru? N(ketimido) bond. |
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| Keywords: | density functional calculations metallophthalocyanines N ligands ruthenium structure elucidation |
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