Jozef Hodyl PhD Thesis - Theses - Flinders University

ands for para substituted aromatic rings expected between 860 and 800 cm -1 are notadequately resolved due to masking by the broad symmetric ν (Si-O-Si) band at ~850 -750 cm -1 .Absorption4000350030002500200015001000500WavenumbersFigure 4.8 DRIFT spectrum of Si-GPS-DiPTrac, 44.4.2.3 Solid State Nuclear Magnetic ResonanceThe obvious difficulty in attempting to characterise the silica attached adducts withsolution based NMR techniques was circumvented by utilising solid state NMRmethodology. Initially 13 C spectra were obtained with Cross polarisation and MagicAngle Spinning for Si-GPS, 33, and Si-GPS-Trac, 43, to ascertain whether thedesired synthetic objective was realised, Figure 4.9.Spectrum A for Si-GPS, 33, correlates suitably with literature values for GPTS,32, and similar organolinker modified silica gel. 219 It is clearly evident from thechemical shifts exhibited in the spectrum for, Si-GPS, 33, that the linker species ispresent and by inference, attached to the silica surface. In addition to the linker81