Proton and carbon NMR

Carbon and Proton NMR Data. 13C and 11NMR chemical shift and coupling constant data for 2-fluoropyridine, 2-fluoroquino-lines, and 2-fluoroquinoxoline are provided in Scheme 3.62. 

Carbon and Proton NMR Spectra of Thiophenes. Some examples that provide proton and carbon data for thiophenes and benzthiophenes that bear a trifluoromethyl group are given in Scheme 5.50. 

Carbon and Proton Spectra of Oxazoles and Thia-zoles. Some examples of carbon and proton NMR data are provided in Scheme 5.57. 

Carbon and Proton NMR Spectra of Trifluorovinyl Compounds. Scheme 6.31 provides the carbon and proton NMR data for a few trifluorovinyl compounds. 

The solid was recrystalhzed from chloroform-methanol to yield brown needle-Uke crystals. The filtrates were concentrated to dryness and the resulting residue was recrystallized from chloroform-methanol. This was repeated a third time and the three crops of catalyst combined to yield 5.102 g (78.2 % isolated yield assuming 98 % pure). The crystals were analysed by carbon and proton NMR and elemental analysis. 

J. Kelm, Forschungsbericbt 213 - Carbon and Proton NMR Spectra Catalogue, Wirtschaftsverlag, Germany, 1995. 

In the case of triphenylene (3), MNDO calculations predict only the 2,4a-dihydro product (4). However, sodium-ammonia reduction produces only one dihydro product (Scheme VII), assigned as 5 on the basis of carbon and proton NMR (19, 20). This result is quite remarkable because this product is unexpected from calculations as well as from comparison with the... 

Structure and tautomeric state can be clearly demonstrated by carbon and proton nmr spectroscopy. The bisenamine can also be... 

The bridged ion is apparently the stable form of the j8-phenylethyl ion in superacid media, as determined by carbon and proton NMR measurements. ... 

While carbon and proton NMR studies are most commonly reported, several of the other nuclei listed in Table 3.1 (fluorine, phosphorus, nitrogen, and silicon) have made important contributions to materials characterisation. Fluorine NMR ranks only below proton NMR in sensitivity and provides a valuable probe of fluorine-containing polymers, such as poly(viny fluoride) [10]. The fluorine chemical shifts are much more sensitive to structural defects than protons, as shown in Figure 3.11, which compares the F spectra for... 

The bridged form of the j8-phenylethyl ion can be observed in super acid media, and can be characterized by carbon and proton NMR spectra. The bridged ion subsequently rearranges to the more stable a-methylbenzyl cation with Ea for the rearrangement being 13 kcal/mol. With more substituted cations the rearrangement to benzyl cations occurs too rapidly for the bridged ion to be observed. 

How do you approach determining a structure of an unknown compound utilizing carbon and proton NMR spectra Let s look at the proton NMR spectrum shown in Figure 6.25. The spectrum is for a compound with formula C6H10O2. The index of hydrogen deficiency for this compound is calculated to be 2. 

---