Exclusively Ligand-Mediated Catalytic Dehydrogenation of Alcohols
Debabrata Sengupta1, Rameswar Bhattacharjee1, Rajib Pramanick1
1Department of Inorganic Chemistry and ΔDepartment of Spectroscopy, Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700 032, India.
Abstract:
Design of an efficient new catalyst that can mimic the enzymatic pathway for catalytic dehydrogenation of liquid fuels like alcohols is described in this report. The catalyst is a nickel(II) complex of 2,6-bis(phenylazo)pyridine ligand (L), which possesses the above requisite with excellent catalytic efficiencies for controlled dehydrogenation of alcohols using ligand-based redox couple. Mechanistic studies supported by density functional theory calculations revealed that the catalytic cycle involves hydrogen atom transfer via quantum mechanical tunneling with significant kH/kD isotope effect of 12.2 ± 0.1 at 300 K. A hydrogenated intermediate compound, [NiIICl2(H2L)], is isolated and characterized. The results are promising in the context of design of cheap and efficient earth-abundant metal catalyst for alcohol oxidation and hydrogen storage.
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