Adsorption of benzidines and anilines on Cu- and Fe-montmorillonites studied by resonance Raman spectroscopy

摘要: Resonance Raman spectroscopy has been used to observe the formation of cation radicals in adsorption N,N,N',N'-tetramethylbenzidine (TMBD), benzidine, N,N- dimethylaniline (DMA) and aniline on Na-, Cu- Fe-montmorillonites. Cation benzidine TMBD, their dications were formed at acid sites montmorillonite surface, or through reduction Cu Fe interlayer ions, adsorbed interlayer. Their structures are represented by biphenoquinone type structure, where inter-ring CC bond ring C-N have double characters. It was demonstrated from spectra that DMA Cu-montmorillonite vapour phase dimerize form TMBD dications. Benzidine blue reaction is a typical colour organic molecules surfaces smectites long investigated number workers. generally agreed clay minerals such as promote oxidation its radical, but there some inconsistencies about proposed state structure oxidized compounds (Matsunaga, 1972; Furukawa & Brindley, 1973; Tennakoon Tricker, 1975; Kovar et al., 1984; McBride, 1985).