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