Structures, relative stability, bond dissociation energies, and stabilization energies of alkynes and imines from a homodesmotic reaction

Abstract On the basis of full optimizations at B3LYP-D3(BJ)/def2-QZVP level, the stabilization energies and relative stability of a series of alkynes and imines with 20 different substituents have been systematically studied with the assistance of the homodesmotic reaction of R-C≡C-H with H2C=N-H to generate H2C=N-R and H-C≡C-H. Some crucial geometries of the R-C≡C-H and H2C=N-R were analyzed and compared with various theoretical tools such as the topology analyses, NCI analyses, LOL-π color-filled maps and localized molecular orbitals. In addition, the bond dissociation energies and the IBSI values, including H-C≡C-H and H2C=N-H, were also calculated for further understanding their relative stability. Based on the B3LYP-D3(BJ) results, the stabilization energies and bond dissociation energies at 298.15 K were estimated by single-point energies at B2PLYP-D3(BJ)/cc-pVTZ level.