Chalcogen analogues of nicotine lactam studied by NMR, FTIR, DFT and X-ray methods.
The selenoanalogue of nicotine has been synthesized and characterized by spectroscopic and X-ray diffraction methods. The crystals of selenonicotine are isomorphic with the thionicotine homologue and consist of molecules engaged in columnar π⋯π stacking interactions between antiparallely arranged pyridine moieties. These interactions, absent in other crystals containing nicotine fragments, seem to be induced by the presence of a lactam group. The molecular structures in the vacuum of the oxo-, thio- and selenonicotine homologues have been calculated by the DFT method and compared with the available X-ray data. The delocalized structure of thionicotine is stabilized by intramolecular C-H⋯S hydrogen bond, which becomes weaker in the partial zwitterionic resonance structure of selenonicotine in favor of multiple C-H⋯Se intermolecular hydrogen-bonds. The calculated data allow a complete assignment of vibration modes in the solid state FTIR spectra. The (1)H and (13)C NMR chemical shifts were calculated by the GIAO method with B3LYP/6-311G(3df) level. A comparison between experimental and calculated theoretical results indicates that the density functional B3LYP method provided satisfactory results for predicting FTIR, (1)H, (13)C NMR spectra properties.
Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland. Electronic address: beatakoz@amu.edu.pl.
Beata
B
Jasiewicz
Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland.
Karolina
K
Malczewska-Jaskóła
Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland. Electronic address: iwkow@amu.edu.pl.
Iwona
I
Kowalczyk
Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland.
Beata
B
Warżajtis
Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland. Electronic address: urszular@amu.edu.pl.
Urszula
U
Rychlewska
D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009538:Nicotine / Q000138:chemical synthesis* / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
D007769:Lactams; D009538:Nicotine
Chalcogen analogues; DFT calculations; NMR spectra; Nicotine selenolactam; Vibrational spectra; X-ray diffraction