Density functional theory study of the interaction of carbon monoxide with the second-row transition-metal dimers

Density-functional theory has been used to determine the ground-state geometrical configurations and electronic states for M2CO (M = Y-Ag except Tc), which reveals that the basis sets for the C, O, and metal atoms have a distinct effect on the harmonic vibrational frequencies but an indistinct one on the geometrical parameters. On going from left to right side of the periodic table, the preference for the coordination mode of CO to transition-metal dimer is from side-on-bonded mode (Y and Zr), via semibridging (Nb and Mo) and bridging (Ru-Pd), to terminal (Ag).