Activation of nitrogen Brønsted acids: synthesis and reactivity of a new class of nitrogen acid complexes

D Scott Bohle; Zhijie Chua

doi:10.1021/ic5017033

Activation of nitrogen Brønsted acids: synthesis and reactivity of a new class of nitrogen acid complexes

Inorg Chem. 2014 Oct 20;53(20):11160-72. doi: 10.1021/ic5017033. Epub 2014 Oct 3.

Authors

D Scott Bohle¹, Zhijie Chua

Affiliation

¹ Department of Chemistry, McGill University , 801 Sherbrooke Street. W., Montreal, Quebec H3A 0B8, Canada.

PMID: 25279421
DOI: 10.1021/ic5017033

Abstract

The nitrogen acids RC(O)NHNO2, N-nitroamide, R = CH3 (1), C2H5 (2) and N-nitrocarbamate, R'OC(O)NHNO2, R' = CH3 (3), C2H5 (4) are a class of primary N-nitrocarboxamide compounds that oxidatively add to trans-Ir((I))(Cl)(N2)(PPh3)2 to give six-coordinate Ir((III))(η(2)-(NO2)-nitrogen acid)(H)(Cl)(PPh3)2 complexes 5-8. Unexpected fluxional behavior of the complexes in solution is observed by (1)H NMR spectroscopy. Reaction intermediates of the oxidative addition reactions were also observed and monitored using (31)P and (1)H NMR and solution IR spectroscopies. Complex 5 reacts with methyl triflate in CH3CN to generate bis(acetonitrile) complex (9) from a net loss of the nitrogen acid anion. P(CH3)2Ph reacts with 5 to give phosphine-substituted and P(CH3)2Ph addition isomers (10). Reactivity studies of 5 with CO gave metastable CO adduct isomer 11, which loses CO on prolonged standing in solution.