Nuclear Magnetic Resonance and Electron Spin Resonance Spectroscopy

The article contains sections titled: 1. Introduction 2. Principles of Magnetic Resonance 2.1. Nuclear and Electronic Properties 2.2. Nuclei and Electrons in a Stationary Magnetic Field 2.3. Basic Principles of the NMR and ESR Experiments 2.4. Relaxation 3. High-Resolution Solution NMR Spectroscopy 3.1. The NMR Experiment 3.1.1. Continuous Wave Methodology 3.1.2. Fourier Transform Methodology 3.2. Spectral Parameters 3.2.1. Chemical Shift 3.2.2. Spin - Spin Coupling 3.2.3. Signal Intensity 3.2.4. Relaxation Times 3.3. NMR and Structure 3.3.1. Hydrogen (1H and 2H) 3.3.2. Carbon (13C) 3.3.3. Fluorine (19F) 3.3.4. Phosphorus (31P) 3.3.5. Nitrogen (14N and 15N) 3.3.6. Oxygen (17O) 3.3.7. Silico…

Using neural networks for (13)c NMR chemical shift prediction-comparison with traditional methods.

Abstract Interpretation of 13 C chemical shifts is essential for structure elucidation of organic molecules by NMR. In this article, we present an improved neural network approach and compare its performance to that of commonly used approaches. Specifically, our recently proposed neural network ( J. Chem. Inf. Comput. Sci. 2000, 40, 1169–1176) is improved by introducing an extended hybrid numerical description of the carbon atom environment, resulting in a standard deviation (std. dev.) of 2.4 ppm for an independent test data set of ∼42,500 carbons. Thus, this neural network allows fast and accurate 13 C NMR chemical shift prediction without the necessity of access to molecule or fragment d…

ChemInform Abstract: Nuclear Magnetic Resonance and Electron Spin Resonance Spectroscopy

Determination of octane numbers of gasoline compounds from their chemical structure by 13C NMR spectroscopy and neural networks

Abstract A new theoretical model has been developed which explains the association between the molecular structure and the knock resistance of individual gasoline compounds convincingly. The constitutions of more than 300 individual gasoline components were correlated with their knock rating (Blending Research Octane Number, BRON) simultaneously. 13C NMR spectra of all compounds were binned in 28 chemical shift regions of different size. The number of individual carbon signals of the nearly 2500 carbons was counted in each shift region and was combined with the information about the presence or absence of the structure groups Oxygen, Rings, Aromatics, aliphatic Chains and oLefins (ORACL). T…