A study of intramolecular hydrogen bonds C-H⋯X (X = N, O) within the theory of the electron localization function

摘要: Electron localization functions (ELFs) are calculated at the hydrogen bond critical points for a number of molecules having intramolecular C-H⋯X (X = N, O). It is shown that values core and valence electrons bifurcation index (CVBI) positive in all cases. This enables characterization studied bonds as weak interactions mainly electrostatic nature. For stronger N-H⋯O with significant contribution covalence to bonding, negative. A relationship between parameters within theory electron function (ELF) quantum “Atoms Molecules” (QTAIM) observed. In 1H NMR spectra, resonance shift bridging atom, induced by much smaller than negative index, interatomic H⋯X distance longer former case. IR spectra corresponds blue stretching vibration covalent donor due bonding red this band.