1227744-08-2Relevant academic research and scientific papers
Interaction of 2-(2′,6′-dialkylphenylazo)-4-methylphenols with iridium. C-H activation and migration of alkyl group
Baksi, Suparna,Seth, Dipravath Kumar,Tadesse, Haregewine,Blake, Alexander J.,Bhattacharya, Samaresh
, p. 1111 - 1118 (2010/05/19)
Reaction of 2-(2′,6′-diethylphenylazo)-4-methylphenol (L2) with [Ir(PPh3)3Cl] afforded two organoiridium complexes 3 and 4 via C-H bond activation of an ethyl group in the arylazo fragment of the L2 ligand. In both the complexes the azo ligand binds to iridium as a dianionic tridentate C,N,O-donor. Two triphenylphosphines and a hydride (in the case of complex 3) or chloride (in the case of complex 4) are also coordinated to the metal center. A similar reaction of [Ir(PPh3)3Cl] with 2-(2′,6′-diisopropylphenylazo)-4-methylphenol (L3) yielded another organoiridium complex 5, where migration of one iso-propyl group from its original location (say, the 2′ position) to the corresponding third position (say, the 4′ position) took place through C-C bond activation. In this complex the modified azo ligand binds to iridium as a dianionic tridentate C,N,O-donor. Two triphenylphosphines and a hydride are also coordinated to the metal center. The structures of complexes 3 and 4 have been optimized through DFT calculations. The structure of complex 5 has been determined by X-ray crystallography. All the complexes show characteristic 1H NMR signals and intense transitions in the visible region. Cyclic voltammetry on all the complexes shows an oxidation within 0.66-1.10 V vs SCE, followed by a second oxidation within 1.15-1.33 V vs SCE and a reduction within -0.96 to -1.07 V vs SCE.
