Natural abundance 15N chemical shifts in substituted benzamides and thiobenzamides15N Substituent chemical shifts (measured at natural abundantc at 0.4 M concentration) and calculated (ab initio, STO-3G) electron densities at the nitrogen and oxygen (or sulphur) are reported for series of para and...
Natural abundance 17O NMR chemical shift data for 10 substituted methyl acetates and 7 analogs, recorded in acetonitrile at 75°C, are reported. Variation in the carbonyl and single-bond oxygen signal are observed for formal α-substitution and do not correlate with inductive effects. The data ...
The title compounds contain groups (amine, amide, imine, carboxylic acid) that are capable of forming intramolecular hydrogen bonds involving a six-membere... L Carlton,B Staskun,TV Es - 《Magnetic Resonance in Chemistry》 被引量: 3发表: 2011年 加载更多来源...
Natural products present in the plant and animal kingdom offer a huge diversity of chemical structures which are the result of biosynthetic processes that ... AttaurRahman - Studies in natural products chemistry / 被引量: 0发表: 1988年 加载更多研究点推荐 natural abundance total syntheses ...
- 《Analytical Chemistry》 被引量: 124发表: 2007年 Suitability of the Diffusion Method for Natural Abundance Nitrogen-15 Analysis Knowing the isotopic signature of inorganic N in soil is an important component in understanding N cycling processes. We tested the suitability of the diff... K ...
A series of 1-substituted-bicyclo[2.2.2]octanes and bicycloalkane-l-carboxylic acids were synthesized and the 13C 13C coupling constants were measured in natural abundance by 13C satellite and/or double-quantum coherence methods. Experimental data for vicinal/geminal coupling between the bridgehead...
This is the definition of natural abundance in chemistry and an explanation of how it relates to atomic weight.
Changes in the natural abundance 13C NMR spectra of intact frog muscle upon storage and caffeine contracture The carbons of phospholipids have limited mobility in fresh, resting, gastrocnemius frog muscle, but a population of phospholipids gains considerable mobil......
To do so, we firstly develop a theory consistent econometric model, in which we show that there is a long run relationship between real income, the investment rate, and the real value of oil production. Secondly, we investigate the long-run (level) impacts of natural resource abundance on ...
Complete carbon connectivities have been determined for two very closely related anthrasteroids, formed in superacidic media, by natural abundance 13C–13C coupling constants observed via double quantum coherence. MC Garcia-Alvarez,G Lukacs,A Neszmelyi,... - 《Journal of Organic Chemistry》 被引量...