Jozef Hodyl PhD Thesis - Theses - Flinders University

224, 225the surface silanol groups.Absorptionfree ν (OH)4000350030002500200015001000500WavenumbersFigure 4.7DRIFT spectrum of silica-based material MCM-41.DRIFT spectra for both the silica immobilised, pegylated, molecular receptorligands Si-GPS-DiPTrac, 44 (Figure 4.8), and Si-GPS-TriPTrac, 45, exhibit twobands at 2981 cm -1 and 2889 cm -1 These bands are in the region associated withasymmetric and symmetric v (C-H) and can be ascribed to the methylene groups of theorganolinker moiety, the pendant arm and the dendritic glycol ether. Other than thisslight increase there doesn't appear to be a great deal of difference between thespectra for the materials with pegylated macrocycles and the material with the nonpegylatedmacrocycle. However, it can be accepted that owing to the appearance ofν (C=C) bands for the macrocycle, which has broadened and lessened in intensity at1600 cm -1 and increased considerably in intensity at 1509 and 1459 cm -1 that thesesilica materials do in fact contain receptor ligands comprising dendritic etherealchains appended to the aromatic rings of the pendant arms. The out-of-plane Ar-H80