SYNTHESIS AND SOLID-STATE NMR STRUCTURAL CHARACTERIZATION OF POLYSILOXANE-IMMOBILIZED AMINE LIGANDS AND THEIR METAL-COMPLEXES

Polysiloxane-immobilized amine and diamine ligand systems have been ma de by hydrolytic condensation of Si(OEt)(4) with (EtO)(3)Si(CH2)(3)NH2 or (MeO)(3)Si(CH2)(3)NH(CH2)(2)NH2. The corresponding triamine ligand was made from the reaction of 3-chloropropylpolysiloxane with diethyl enetriamine (H2NCH2CH2NHCH2CH2NH2); solid-state C-13 and N-15 nuclear magnetic resonance (NMR) spectra can identify the structure of the pro duct of this reaction. Si-29, N-15, C-13 and H-1 NMR spectra are in ge neral valuable for characterizing these polysiloxane structures, and p rovide evidence for the involvement of the amine ligands in hydrogen b onding with surface silanols. Together with results of classical eleme ntal analysis, the NMR data indicate that a portion of the ligand grou ps are inaccessible to metal ions and remain uncoordinated when these materials are treated with aqueous solutions of divalent metal ions. S i-29 NMR spectra and elemental analysis reveal some details of the lea ching of these polysiloxane materials, when they are treated with acid s or metal ion solutions. Relaxation times, T-1(H), were measured, bas ed on Si-29 and C-13 detection, on the polysiloxane-immobilized ligand systems. The T-1(H) results suggest that the organofunctionalities in these systems are evenly distributed in the polysiloxane network.