Synthesis and evaluation of silica hydride‐based fluorinated stationary phases

Revealing the Fine Details of Functionalized Silica Surfaces by Solid‐State NMR and Adsorption Isotherm Measurements: The Case of Fluorinated Stationary Phases for Liquid Chromatography

“…It is Surface chemistry of bonded silica phases 29 Si and 13 C CPMAS NMR spectroscopy has been widely used in the last twenty years to investigate the structure and dynamics of chemically modified silica gels. [18,[53][54][55][56][57][58][59] Cross-polarization improves the sensitivity of heteronuclear solid-state experiments by transferring magnetization from abundant hydrogen nuclei to rare heteronuclei such as 29 Si and 13 C. [54,55] Since peak intensity is modulated by transferring the magnetization from hydrogen to silicon atoms, [60] 29 Si CPMAS spectra collected at a given contact time cannot be used for signal quantification. On the other hand, 29 Si MAS spectra collected with a suitably long recycle delay can be used for quantitative purposes.…”

Synthesis, characterisation and chromatographic evaluation of pentafluorophenyl and phenyl bonded silica phases prepared using supercritical carbon dioxide as a reaction solvent

“…A number of retention mechanisms have been postulated for solute retention on fluorinated phases: dipole-dipole interactions in the case of fluoro/halo or polar/non-polar types of compounds; for fluorinated phenyl phases -interactions for phenyl-based compounds; charge transfer and ion-exchange mechanism (from the silanol groups of the underlying silica) for biological ionic compounds [18][19][20][21][22][23]. In a chromatographic environment, the -interactions can occur between -electrons of the stationary phase and the analyte species [19][20][21] and are favoured when the analyte is electron deficient [24,25].…”

The Development of Silica Hydride Stationary Phases for High Performance Liquid Chromatography from Conception to Commercialization

“…This feature is responsible for the long lifetime of these reversedphase column materials. The versatility of the hydrosilation reaction has been demonstrated over the years by bonding a wide variety of alkenes and alkynes to the silica hydride surface [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Some examples of organic moieties attached to silica hydride and tested as potential stationary phases are shown in Figure 2.…”