Appraising the relative strengths of C-H***O=C and N-H***O=C interactions from cis-N-methylacetamide multimers

Simon Mathieu (1) , Georges Trinquier (1)

1 Chimie des éléments d & f (LCPQ)

The strength of C-H***O=C interactions relative to regular N-H***O=C hydrogen bonds is estimated from DFT quantum calculations on multimers of cis-N-methylacetamide (NMA). Assuming transferable hydrogen-bond increments, treatment of various constraint-free NMA dimers and trimers enables us to provide statistical values for (i) the direct energy difference between the two kinds of interaction (calculated around 5 kcal mol(-1)), and (ii) their associated binding energies, hence the ratio of their strengths. Combining the binding energies with other critically-analyzed observables, a relative strength of about 20%-say no more than one fifth-is finally proposed.

Domaines: Autre

Simon Mathieu, Georges Trinquier. Appraising the relative strengths of C-H***O=C and N-H***O=C interactions from cis-N-methylacetamide multimers. Physical Chemistry Chemical Physics, 2009, 11 (37), pp.8183-90. ⟨10.1039/b908152f⟩. ⟨hal-00835593⟩