Ortho-Substituent Effects on Halogen Bond Geometry for N-Haloimide⋯2-Substituted Pyridine Complexes.

ABSTRACT: The nature of (imide)N-X⋯N(pyridine) halogen-bonded complexes formed by six N-haloimides and sixteen 2-substituted pyridines are studied using X-ray crystallography (68 crystal structures), Density Functional Theory (DFT) (86 complexation energies), and NMR spectroscopy (90 association constants). Strong halogen bond (XB) donors such as N-iodosuccinimide form only 1:1 haloimide:pyridine crystalline complexes, but even stronger N-iodosaccharin forms 1:1 haloimide:pyridine and three other distinct complexes. In 1:1 haloimide:pyridine crystalline complexes, the haloimide's N─X bond exhibits an unusual bond bending feature that is larger for stronger N-haloimides. DFT complexation energies (ΔE_XB ) for iodoimide-pyridine complexes range from -44 to -99 kJ mol^-1 , while for

SUBMITTER: Yu S 

PROVIDER: S-EPMC10853718 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature