EXPERIMENTAL AND THEORETICAL NMR STUDY OF 4-(1-PYRROLIDINYL)PIPERIDINE

ALVER Ö., PARLAK C., BİLGE M.

BULLETIN OF THE CHEMICAL SOCIETY OF ETHIOPIA, vol.25, no.3, pp.437-442, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 25 Issue: 3
  • Publication Date: 2011
  • Journal Name: BULLETIN OF THE CHEMICAL SOCIETY OF ETHIOPIA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.437-442
  • Keywords: 4-(1-Pyrrolidinyl)piperidine, NMR, DFT, Axial, Equatorial, SPIN COUPLING-CONSTANTS, DFT CALCULATIONS, AB-INITIO, MOLECULAR-STRUCTURE, N-15 NMR, C-13, SPECTRA, COMPLEX, SHIELDINGS, (1)J(CH)
  • Anadolu University Affiliated: Yes

Abstract

The possible stable forms and molecular structure of 4-(1-pyrrolidinyl)piperidine (4-pypp) have been studied experimentally and theoretically using nuclear magnetic resonance (NMR) spectroscopy. H-1, C-13, N-15, DEPT, COSY and HETCOR NMR spectra of 4-pypp (C9H18N2) have been reported. Solvent effects on nuclear magnetic shielding tensors have been investigated using chloroform-d, methanol-d, acetone-d, dimethylsulfoxide-d and water-d. The magnitude of (n)J(C,H) (n = 1, 2, 3) coupling constants of 4-pypp have been determined with selective H-1 decoupled C-13 NMR techniques. H-1, C-13, N-15 NMR chemical shifts and (1-3)J(C,H) coupling constants have also been calculated for the most stable two conformers, equatorial-equatorial (e-e) and axial-equatorial (a-e) forms of 4-pypp using DFT/6-311++G(d,p)//6-31G(d) level of theory. Results from experimental and theoretical data have showed that the molecular geometry and the mole fractions of stable conformers of 4-pypp are solvent dependent.