Activation and Coordination of Ammonia at [Cp*Ir(H)2]: NMR and Matrix Isolation Studies |
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| Authors: | Dr. Ann‐Katrin Jungton Dr. Christian Herwig Prof. Dr. Thomas Braun Prof. Dr. Christian Limberg |
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| Affiliation: | Department of Chemistry, Humboldt‐Universit?t zu Berlin, Brook‐Taylor‐Str. 2, 12489 Berlin (Germany), Fax: (+49)?30‐2093‐6966 |
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| Abstract: | 1H NMR exchange spectroscopy of a reaction mixture of [Cp*Ir(H)4] ( 1 ; Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl) and ammonia suggests an exchange of hydrogen atoms between the hydrido ligands and ammonia. Treatment of 1 with ND3 led to an H/D exchange between ND3 and the hydrido ligands of 1 . Subsequent studies showed that photolysis of 1 isolated in frozen argon matrices leads to the formation of the iridium compounds [Cp*Ir(H)2] ( 2 ) and [Cp*Ir(H)3] ( 4 ), as it was confirmed by IR spectroscopy. In the presence of water the aqua complex [Cp*Ir(H)2(OH2)] ( 3 ) was generated simultaneously. Accordingly, photolysis of 1 in an argon matrix doped with ammonia gave rise to the ammine complex [Cp*Ir(H)2(NH3)] ( 5 ). IR assignments were supported by calculations of the gas‐phase IR spectra of 1 – 5 by DFT methods. |
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| Keywords: | ammonia activation density functional calculations hydrido complexes iridium matrix isolation |
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