## Abstract The dipeptide alanylproline has been prepared with the proline residue both ^13^C (15%) and ^15^N (95%) enriched. ^15^N NMR spectra of alanylproline reveal signals for both possible conformations—__cis__ and __trans__—of the dipeptide backbone in solution. Different p__K__ values for bo
Theoretical and experimental 13C and 15N NMR investigation of guanylhydrazones in solution
✍ Scribed by Tales L. C. Martins; Teodorico C. Ramalho; José D. Figueroa-Villar; Alex F.C. Flores; Cláudio M. P. Pereira
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 130 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.1299
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Experimental and theoretical ^15^N and ^13^C NMR data for the three nitrobenzaldehyde guanylhydrazones are reported. The theoretical data were obtained using sequential molecular dynamics/quantum mechanics methodology for the calculation of flexible molecules in a condensed phase, followed by the use of the GIAO/DFT method with the 6–311G** basis set. The experimental ^15^N chemical shifts for the guanylhydrazones are compared with the calculated shifts. Copyright © 2003 John Wiley & Sons, Ltd.
📜 SIMILAR VOLUMES
## Abstract The ^13^C [hexadeutero‐dimethylsulfoxide (DMSO‐__d__~6~), hexamethyl‐phosphoramide (HMPA)‐__d__~18~and solid‐state] and ^15^N (solid‐state) NMR spectra of six __C__‐aminobenzimidazoles have been recorded. The tautomerism of 4(7)‐aminobenzimidazoles and 5(6)‐aminobenzimidazoles has been
The optimum 14 N pulse lengths in the 13 C-14 N rotationalecho adiabatic-passage double-resonance (REAPDOR) NMR experiment are determined from calculations and from experiments on samples of glycine and L-alanine. The REAPDOR experiment utilizes the adiabatic passages that 14 N spins make between th
## Abstract NMR spectroscopic studies are undertaken with derivatives of 2‐pyrazinecarboxylic acid. Complete and unambiguous assignment of chemical shifts (^1^H, ^13^C, ^15^N) and coupling constants (^1^H,^1^H; ^13^C,^1^H; ^15^N,^1^H) is achieved by combined application of various 1D and 2D NMR spe
The tautomerism and isomerism of triazoles make the structure analysis of such compounds a difficult problem, and in the case of several nitrotriazoles a detailed structure assignment had been lacking up to now. Supported by selected compounds, a deÐnite structure determination of ten nitrotriazoles
It is shown that both I3C and ''N NMR measurements provide similar estimates of the position of the prototropic equilibrium exhibited by 2-hydroxy-3-methylindazole in three solvents. The "N NMR study of the pyridine and pyrrole types of nitrogen atoms provided the most quantitatively reliable result