13C NMR studies of organosilanes : IV. Vinyl- and allyl-silanes

The ¹³C NMR spectra of 29 silanes containing vinyl and allyl groups have been recorded and assigned. The chemical shifts have been correlated using substiuent-chemical-shift factors for groups and atoms attached to the silicon atom. A high correlation is demonstrated between the spectral results for the vinyl compounds and the corresponding phenylsilanes.     

13C n.m.r. studies of organosilanes: II—substituent chemical shift parameters for alkoxysilanes

The ¹³C n.m.r. spectra of forty alkoxysilanes of the general type X_nSi(OR)_4–n (X = CH₃, C₆H₅, H; R = CH₃, C₂H₅, n-C₃H₇, i-C₃H₇, n-C₄H₉, i-C₄H₉, s-C₄H₉, n-C₅H₁₁, CH(CH₃)(C₆H₅), C₆H₅) have been recorded and assigned. The chemical shifts of the α-carbon resonances of the alkoxy groups are shown to depend on both the nature of the alkoxy group and the number and type of substituents on the silicon. Regression analyses of the data give empirical substituent chemical shift (SCS) parameters for the silyl substituents. The β-carbon resonances are shown to be dependent on the presence of the silyl group, but not the specific silyl substituents.     

An alternative approach to combination vaccines: intradermal administration of isolated components for control of anthrax,botulism, plague and staphylococcal toxic shock

Background  

Combination vaccines reduce the total number of injections required for each component administered separately and generally provide the same level of disease protection. Yet, physical, chemical, and biological interactions between vaccine components are often detrimental to vaccine safety or efficacy.