Reduction of CO2 and SO2 with low valent nickel compounds under mild conditions

Abstract

The reaction of [(dippe)Ni(μ-H)]₂ (A) (dippe = 1,2-bis(diisopropyl-phosphinoethane) with CO₂ in toluene afforded the carbonyl nickel(0) compounds of the type {(dippe)Ni(CO)]₂(μ-dippe)}(1) and (dippe)Ni(CO)(dippeO)] (2), which were characterized by standard spectroscopic methods; complex (1) was also characterized by single crystal X-ray diffraction. Reaction of (A) with SO₂ yields the thiosulfate nickel(II) compound [Ni(dippe)(S₂O₃)] (5), which was fully characterized by standard spectroscopic methods and X-ray crystallography. In both cases, a reduction reaction of CO₂ to CO and SO₂ to S₂O₃²⁻ with (A) took place under mild conditions.