Synthesis and metal coordination of thioether containing cyclo- and poly(organophosphazenes)

Several small molecule cyclotriphosphazenes and high polymeric poly(organop hosphazenes) with methylthio groups (CH3SR) have been synthesized: [NP(OCH2 CH2SCH3)(2)](n) (n = 3, 1; n = 15,000, 5); [NP(OCH2CH2CH2CH2SCH3)(2)](n) (n = 3, 2; n = 15,000, 6); [NP(OCH2CH2CH(SCH3)CH2CH2CH3)(2)](n) (n = 3, 3; n = 15,000, 7); and [NP(OCH2C6H4SCH3)(2)](n) (n = 3, 4; n = 15,000, 8). Both series of compounds possess multiple thioether coordination sites for poten tial binding to metals. The methylthioethoxide substituent readily oxidizes to the sulfoxide derivatives in the presence of peroxides. All the phospha zenes were characterized by H-1-, C-13-, and P-31-NMR spectroscopy and elem ental analysis, and the small molecule cyclotriphosphazenes were examined b y mass spectrometry. Gel permeation chromatography (GPC) and differential s canning calorimetry (DSC) were also employed to characterize the polymers. Metal complexation and extraction capabilities of both the small molecule a nd polymeric systems are described. (C) 2000 John Wiley & Sons, Inc.