Roberto Rittner Neto

• Abstract

  The conformational analysis of some esters with a nitrogen atom as a substituent, through 1H and 13C NMR spectroscopy, infrared spectroscopy and theoretical calculations. The theoretical calculations will be performed at MP2 and DFT level of theory, using several basis sets, and including Zero-Point corrections (ZPE), available in the Gaussian-09 for the determination of the energies and …

  Conformational Analysis of Some Aliphatic Esters Bearing a Nitrogen Atom as a Substituent, AP.R

• Abstract

  The conformational analysis of some amino acids derivatives, esterified and acetylated, as well as of some dipeptides is proposed. This is an advanced project in comparison to a previous one since it will focus on more complex structures and also on the application of the most recent theoretical methods, used in physical organic chemistry. The experimental work will be based in NMR spectr…

  Molecular structure of some amino acids and dipeptides, AP.R

• Abstract

  This project involves the study of the conformational analysis of several aminoacids as well as models of dipeptides (N-acetyl-R-N-methylamide: R=glycine, alanine, valine, phenylalanine and tyrosine), through NMR spectroscopy (H-1, C-13 and N-15) and by infrared spectroscopy and theoretical calculations of electronic structure. The theoretical calculations will be performed at ab initio M…

  Conformational equilibria and intramolecular interactions for a series of amino-acids: theoretical and experimental approaches, AP.R

(Only some records are available in English at this moment)

• Abstract

  The conformational analyses of some aminoacids derivatives and related compounds, through NMR (H-1 and C-13) and infrared spectroscopies, and theoretical calculations is proposed. These calculations will employ the ab initio MP2 and the DFT wB97X-D methods including zero point energy corrections, which are available in Gaussian-97 and will give the geometries and energies for the most sta…

  Conformational analyses of aminoacids derivatives: a theoretical and experimental approach, BP.MS

• Abstract

  NMR is a powerful tool for chemical structure elucidation; however it is less used when dealing with complex mixtures, since it becomes hard to distinguish overlapping signals and to correlate signals to each chemical species under analysis. In NMR spectroscopy one of the most employed methods for intact mixture analysis is diffusion-ordered spectroscopy (DOSY). This method relays on diff…

  Development and application of NMR techniques to analyse complex mixtures, BP.DR

• Abstract

  It is proposed the conformational analysis of esters and N-acetyl derivatives of some aminoacids as proline, aspartic acid, cysteine and histidine, through NMR spectroscopy (H-1, C-13 and N-15), infrared spectroscopy and theoretical calculations. The theoretical calculations will be performed using the MP2 ab initio method and, also, several functionals of Density Functional Theory (DFT) …

  Conformational investigation of amino acid derivatives and corresponding intramolecular interactions through NMR and IR spectroscopies and theoretical calculations, BP.DR

(Only some records are available in English at this moment)

• Abstract

  Mixture analysis is among the most important areas of chemistry research: most of Mother Nature's interesting problems present themselves as mixtures. In the work proposed here a novel approach to the use of NMR spectroscopy to monitor organic reactions will be investigated. NMR is well suited to following chemical reactions, especially when signals are well resolved. However, when signal…

  Multi-way diffusion NMR data analysis applied to chemical reaction monitoring, BE.EP.DR

• Abstract

  Animal venoms consist of a complex variety of bioactive molecules, among which the vast majority are small peptides, referred to as toxins, stabilized by multiple disulfide bonds. These compounds have been an attractive source for the development of novel therapeutic agents and bioinsecticides due to their high degree of potency and selectivity against a wide range of neuronal receptors a…

  Investigating the structural complexity of ancient Australian arthropod venoms, BE.EP.DR

• Abstract

  It is proposed the determination of enantiomeric excess and absolute configuration of a series of enantiomeric mixtures using chiral lanthanide shift reagents. Enantiomerically pure compounds, either commercial or obtained by enantioselective synthesis will be analyzed by nuclear magnetic resonance (NMR) in the presence and absence of chiral lanthanide shift agents. Knowing the behavior o…

  NMR characterization of some modified nucleoside bases related to 8-nitroguanine, BE.EP.MS