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Complete experimental and theoretical proton and carbon nuclear magnetic resonance spectral assignments, molecular structure and conformational study of 1‐cyclohexylpiperazine and 1‐(4‐pyridyl)piperazine
Author(s) -
Alver Özgür
Publication year - 2010
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2538
Subject(s) - chemistry , conformational isomerism , piperazine , molecule , magic angle spinning , nuclear magnetic resonance spectroscopy , dept , crystallography , chemical shift , carbon 13 nmr , proton nmr , nuclear magnetic resonance , stereochemistry , organic chemistry , physics
The possible stable forms and molecular structures of 1‐cyclohexylpiperazine (1‐chpp) and 1‐(4‐pyridyl)piperazine (1‐4pypp) molecules have been studied experimentally and theoretically using nuclear magnetic resonance(NMR) spectroscopy. 13 C, 15 N cross‐polarization magic‐angle spinning NMR and liquid phase 1 H, 13 C, DEPT, COSY, HETCOR and INADEQUATE NMR spectra of 1‐chpp (C 10 H 20 N 2 ) and 1‐4pypp (C 9 H 13 N 2 ) have been reported. Solvent effects on nuclear magnetic shielding tensors have been investigated using CDCl 3 , CD 3 OD, dimethylsulfoxide (DMSO)‐ d 6 , (CD 3 ) 2 CO, D 2 O and CD 2 Cl 2 . 1 H and 13 C NMR chemical shifts have been calculated for the most stable two conformers, equatorial–equatorial (e–e) and axial–equatorial (a–e) forms of 1‐chpp and 1‐4pypp using B3LYP/6‐311++G(d,p)//6‐31G(d) level of theory. Results from experimental and theoretical data showed that the molecular geometry and the mole fractions of stable conformers of both molecules are solvent dependent. Copyright © 2009 John Wiley & Sons, Ltd.