A DFT study on the mechanism of the gas phase reaction of niobium with acetaldehyde

The reaction between niobium atom and acetaldehyde has been investigated with a DFT approach. Both ground and excited state potential energy surfaces are investigated in detail. The present results show that the title reaction starts with the formation of a η 2 -CH3CHO-metal complex followed by CC, aldehyde CH, methyl CH and CO bond activation. These reactions can lead to several different products, viz., NbCO+CH4, NbCOCH2+H2, NbCOCH3+H, NbCHO CH2+H, NbH+CH3CO, NbO+CH3CH and NbO+C2H4. The spin-forbidden reaction, 6 Nb+CH3CHO → 2 IM9 is found to be energetically most favorable. According to the identified reaction mechanisms, the sextet-quartet and quartet-doublet surface crossings are suggested and the crossing region is approximately determined. The present results may be helpful in understanding the mechanism of the title reaction and in experimental investigations of the reaction.