Carbonyl⋯carbonyl interactions in first-row transition metal complexes
Abstract
O moieties (Tr = first-row
O systems show an increased tendency to form close CO⋯CO interactions, with 45% of these forming pairwise interactions in a sheared antiparallel dimer motif and 55% having a perpendicular (single interaction) geometry. The bulky Tr and steric hindrance arising from other
O systems are slightly stronger than for organic
O bond dipole in Tr–C
O systems. With interaction energies comparable to those for medium strength hydrogen bonds, we conclude that CO⋯CO interactions in Tr–C
O species may have a role to play in the design of novel