gNMR simulated H-1 and proton-coupled C-13 NMR spectra of substituted 3-nitropyridines. GIAO/DFT calculated values of proton and carbon chemical shifts and coupling constants

Katritzky A. R., Akhmedov N. G., Guven A., Doskocz J., Akhmedova R. G., Majumder S., ...More

JOURNAL OF MOLECULAR STRUCTURE, vol.787, no.1-3, pp.131-147, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 787 Issue: 1-3
  • Publication Date: 2006
  • Doi Number: 10.1016/j.molstruc.2005.10.041
  • Journal Name: JOURNAL OF MOLECULAR STRUCTURE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.131-147
  • Keywords: long-range coupling constants, GIAO, 3-nitropyridines, proton-coupled C-13 NMR spectra, NUCLEAR-MAGNETIC-RESONANCE, AB-INITIO, CHARGE-DISTRIBUTION, H-1-NMR SPECTRA, PYRIDINE, DERIVATIVES, N-15, RANGE, SPECTROSCOPY, ASSIGNMENTS
  • Anadolu University Affiliated: No

Abstract

The magnitude of one bond and long-range coupling constants in 3-nitropyridine 1 and its derivatives 2-16 were determined from the proton-coupled C-13 NMR spectra in CDCl3. The GIAO/DFT (Density Functional Theory/Gauge Including Atomic Orbitals) calculations on B3LYP/6-31 +G(d,p)//6-31G(d) and B3LYP/6-311 + +G(d,p)//6-31G(d) optimized structures of 1-16 were employed for the determination of proton and carbon chemical shifts and coupling constants ((n)J(HH) and (n)J(CH)) and the calculated data compared with the experimental NMR data. The GIAO/DFT calculations, in conjugation with iterative simulations of the proton-coupled C-13 NMR spectra using gNMR software, provide reliable values of (n)J(CNO2,H) couplings, which could not be obtained from the proton-coupled C-13 NMR spectra of 1-16 due to line broadening associated with quadruple relaxation involving the N-14 nuclei and non-zero C-13-N-14 couplings. (c) 2005 Elsevier B.V. All rights reserved.