Silica-mounted FTIR-active organometalcarbonyl derivatives as functional materials

Organometalcarbonyl complexes adsorbed onto silica and covalently attached to similar to63 mum, similar to15 mum and similar to7 nm diameter silica particles have been studied by IR and Si-29 MAS NMR. The properties of the characteristic vibrational stretching modes of the M-CO groups examined by FTIR spectroscopy using ATR, DRIFT, and an optrode assembly, are discussed. In the Si-29 NMR spectra, an additional signal in the -20 ppm region was observed in the presence of the covalently attached organometallic, and the intensity of the Q(3) band shoulder of the main bulk Q(4) silica signal at -110 ppm was reduced in intensity. Determination of surface loading of the silica by microanalysis, AA, DRIFT and Si-29 NMR is compared. The FTIR spectra are compared by the use of Bellamy plots, and normalised differential response ratios are used to quantify the contributions of environmental effects on the relative positions of the v(CO) vibrational stretching modes of organometallic complexes. The terms Delta(R) and Delta(N) are defined.