Silver, colloidal organosols

Surfactant stabilized organosols have been prepared by extraction of the colloidal metal into an immisdble organic liquid from a preformed hydrosol. Reduction of H2PtQ by NaBH, in water containing cetyltributylphosphonium bromide followed by extraction into toluene gave a stable organosol of platinum. [65] Colloidal silver partides (8 nm) were displaced from water into cydohexane. 

SER effects have been observed for a number of adsorbates on copper hydro-sols. Triphenylphosphine, diphenyl sulfide, and benzotriazole all partially displace adsorbed pyridine from colloidal copper and result in SER spectra which contain both pyridine bands and those of the coadsorbate. Diphenyl sulfide and thio-phenol were found to displace pyridine. [207] A similar displacement of pyridine by thiophenol was observed with copper organosols. [218] Tliese results exemplify the potential of this technique for investigating the surface coordination chemistry of colloidal metals. SER spectra of cytosine and of guanine and their derivatives on copper and on silver have been reported. [219, 220]... 

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