Nuclear magnetic resonance spectroscop chemical shift

Quantum chemical nuclear magnetic resonance (NMR) chemical shift calculations enjoy great popularity since they facilitate interpretation of the spectroscopic technique that is most widely used in chemistry [1-11], The reason that theory is so useful in this area is that there is no clear relationship between the experimentally measured NMR shifts and the structural parameters of interest. NMR chemical shift calculations can provide the missing connection and in this way have proved to be useful in many areas of chemistry. A large number of examples including the interpretation of NMR spectra of carbocations [12], boranes [10, 13], carboranes [10, 13-15], low-valent aluminum compounds [16-18], fullerenes [19-21] as well as the interpretation of solid-state NMR spectra [22-26] can be found in the literature. 

Nuclear magnetic resonance (NMR) spectroscopy is the most powerful spectroscopic method for structural elucidation of organic molecules and is routinely used by organic chemists. Summarised below are common NMR active nuclei chemical shift data for NMR solvents, common impurities, and functional groups coupling constants and details of common NMR experiments used to determine the connectivity and stereochemistry of small organic molecules. 

H and nuclear magnetic resonance (NMR) spectroscopic data for all indicated dithiiranes have been reported and important chemical shifts are collected in Table 1. The configurations of the sulfmyl sulfur of 18 and 19 have been assigned by comparison of the chemical shifts of the geminal methyl groups with those of known cis- and trans-dithiirane A-oxides <1995TL1867>. 

Nuclear magnetic resonance (NMR) spectroscopy has had a strong influence in the development of B12 chemistry. The early NMR spectroscopic studies established the nature of many noncrystalline Bi2-derivatives, mostly in their CO/3-cyano forms, using one-dimensional analyses. These studies were based on the H- and C-chemical shift values from spectra of several already well-characterized B12-derivatives and used to identify and describe the structure of synthetic and natural analogues of vitamin B12 [74]. The natural corrinoids from a range of bacteria were first characterized by NMR [75,76]. 

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