13C chemical shifts in medium ring and macrocyclic ketolactones
نویسندگان
چکیده
منابع مشابه
Calculation of 13C chemical shifts in rna nucleosides: structure-13C chemical shift relationships.
Isotropic 13C chemical shifts of the ribose sugar in model RNA nucleosides are calculated using SCF and DFT-GIAO ab initio methods for different combinations of ribose sugar pucker, exocyclic torsion angle, and glycosidic torsion angle. Idealized conformations were obtained using structures that were fully optimized by ab initio DFT methods starting with averaged parameters from a collection of...
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Pressure-dependent (13)C chemical shifts have been measured for aliphatic carbons in barnase and Protein G. Up to 200 MPa (2 kbar), most shift changes are linear, demonstrating pressure-independent compressibilities. CH(3), CH(2) and CH carbon shifts change on average by +0.23, -0.09 and -0.18 ppm, respectively, due to a combination of bond shortening and changes in bond angles, the latter matc...
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Deuterium substitution on two ortho-substituted-OCH2-fragments in Nitro-Benzo-9-Crown-3 induces low frequency shifts, positive mnDCj, in all 13C NMR resonances which is an indication of the increased shielding in this crown ether. The magnitude of these shifts vary from 15DC7=716 to 54D<...
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The 13C chemical shifts for a series of compounds which includes carboxylic acids, aldehydes, ethers, ketones and hydrocarbons were simulated by using the parametric techniques. The observed chemical shifts were related to numerically encoded structural parametes called descriptors. Two new electronic descriptors were added to the previous descriptors. Ploting of experimental ver...
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ژورنال
عنوان ژورنال: Canadian Journal of Chemistry
سال: 1977
ISSN: 0008-4042,1480-3291
DOI: 10.1139/v77-454