Infrared spectrum and structure of Ni(CO)2: A matrix isolation and DFT study Original Research Article

The infrared spectrum of nickel dicarbonyl, Ni(CO)2, a coordinatively unsaturated species produced by the cocondensation of ground state nickel atoms with CO molecules isolated in solid argon at low temperature, was reinvestigated. New data concerning twelve overtones, combinations and fundamentals in the near-, mid- and far-infrared regions led to assignments of seven out of nine fundamental vibrations. These data show unambiguously that the structure of the Ni(CO)2 is bent, not linear, as previously thought. Density functional calculations of the geometrical, electronic and vibrational properties of Ni(CO)2 are presented and compared to the experimental values. Comparison of the evolution of the Ni–C force constants and binding energies in NiCO and Ni(CO)2 is also presented.