Conformational studies by 1H - NMR in a nematic solvent

Methyl isonicotinate, methyl nicotinate and methyl picolinate

Hajime Kiyono, Kaori Inoue, Hiroshi Takeuchi, Shigehiro Konaka

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The structures of methyl isonicotinate (MI), methyl nicotinate (MN) and methyl picolinate (MP), i.e., 4-, 3-, and 2-pyridinecarboxylic acid methyl esters, were studied by 1H - NMR at 296 K using nematic liquid-crystal solvent ZLI 1167. Conformational analysis was performed according to the model of Emsley, Luckhurst and Stockley to take account of the correlation between rotation and internal rotation. Only the conformer with a planar skeleton was detected for MI but s-trans and s-cis conformers were found for MN and MP. The relative abundance of the s-trans form was determined to be 64(2) and 68(2)% for MN and MP, respectively, which are in agreement with those determined by gas-phase electron diffraction. The positions of the ring protons of MI in ZLI 1167 agree with those in the gas phase within experimental errors. In the case of MN and MP, however, observed direct coupling constants between the ring protons are in poor agreement with those calculated from the gas-phase structures due to the deformation of the pyridine rings in ZLI 1167.

Original languageEnglish
Pages (from-to)73-80
Number of pages8
JournalJournal of Molecular Structure
Volume476
Issue number1-3
DOIs
Publication statusPublished - 1999 Feb 23
Externally publishedYes

Fingerprint

Nuclear magnetic resonance
vapor phases
nuclear magnetic resonance
rings
Gases
protons
Protons
musculoskeletal system
esters
pyridines
electron diffraction
liquid crystals
Nematic liquid crystals
Niacin
Phase structure
acids
Electron diffraction
Esters
methyl nicotinate
picolinic acid

Keywords

  • Conformation
  • Methyl isonicotinate
  • Methyl nicotinate
  • Methyl picolinate
  • NMR

ASJC Scopus subject areas

  • Structural Biology
  • Organic Chemistry
  • Physical and Theoretical Chemistry
  • Spectroscopy
  • Atomic and Molecular Physics, and Optics

Cite this

Conformational studies by 1H - NMR in a nematic solvent : Methyl isonicotinate, methyl nicotinate and methyl picolinate. / Kiyono, Hajime; Inoue, Kaori; Takeuchi, Hiroshi; Konaka, Shigehiro.

In: Journal of Molecular Structure, Vol. 476, No. 1-3, 23.02.1999, p. 73-80.

Research output: Contribution to journalArticle

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