Theoretical studies on the conformations of selenamides

[摘要] Ab initio HF/6-31+𝐺*, MP2/6-31+𝐺*, B3LYP/6-31+𝐺* level calculations have been performed on HSe-NH2 to estimate the Se-N rotational barriers and N-inversion barriers. Two conformers have been found with syn and anti arrangement of the NH2 hydrogens with respect to Se-H bond. The N inversion barriers in selenamide are 1 65, 2 47, 1 93 kcal/mol and the Se-N rotational barriers are 6 58, 6 56 and 6 12 kcal/mol respectively at HF/6-31+𝐺*, MP2/6-31+𝐺* and B3LYP/6-31+𝐺* levels respectively. The 𝑛N → 𝜎*Se-H negative hyperconjugation is found to be responsible for the higher rotational barriers.

[关键词] Selenamides;Se-N interactions;conformations;ab initio calculations.