The Inclusion of Organometallic Derivatives of Cyclotriphosphazenes Inside SiO2 Matrix and Their Conversion to Nanostructured Metal-Oxides and Phosphates

Organometallic derivatives of the cyclotriphosphazene N3P3[OC6H4CH2CN·TiClCp2]6 (1), N3P3(O6H5)5[OC6H4N·W(CO)5] (2), N3P3[OC6H4CH2CN·Mo(CO)5]6 (3), [N3P3(O6H5)5(OC5H4N·CpRu(PPh3)2)][PF6] (4), [N3P3(O2C12H8)2OC5H4N·Ag(PPh3)][OSO2CF3] (5), N3P3[OC6H5]5 [OC5H4N·Cu][PF6] (6) and N3P3[OC6H4CH2CN·CuCl]6[PF6]6 (7),were incorporated inside SiO2 through the sol–gel method. The metal–organic nanocomposites of the general formula N3P3[OC6H4CH2CN·TiClCp2]6·nSiO2 (G 1 ), N3P3[OC6H4N·W(CO)5]·nSiO2 (G 2 ), N3P3[OC6H4CH2CN·Mo(CO)5]6·nSiO2 (G 3 ), N3P3(O6H5)5OC5H4N·CpRu(PPh3)2][PF6]·nSiO2 (G 4 ), [N3P3(O2C12H8)2OC5H4N·Ag(PPh3)][OSO2CF3]·nSiO2 (G 5 ), N3P3[OC6H5]5[OC5H4N·Cu][PF6]·(SiO2) n (G 6 ), and N3P3[OC6H4CH2CN·CuCl]6[PF6]6·(SiO2) n (G 7 ), were characterized by IR spectroscopy; 12C, 31 P and 29Si MAS NMR measurements as well as UV–Visible diffuse reflectance spectra, indicating the presence of the respective organometallic derivatives of the cyclotriphosphazene incorporated into SiO2. Pyrolysis of these nanocomposites under air at 800 °C gives rise to nanostructured metal-oxides and metal phosphates incorporated into amorphous SiO2, with the presence in some cases of complexes phase mixtures. From some precursors, we obtained metal-oxides/phosphates nanoparticles separated from the SiO2 nanoparticles instead the oxides/phosphates nanoparticles inside the SiO2 matrix. Additionally and for comparison purposes, we used the compound N3P3[NH(CH2)3Si(OEt)3]6 as gelator. Nanocomposites (G′ 1 ), (G′ 2 ) and (G′ 3 ) exhibited mainly morphological differences while in some cases composition differences when using TEOS as gelator. Some simple metal-containing compounds as (O3SCF3)Ag(PPh3)(HOC5H4N), [CuCl2·NC5H4OH] and [CuCl2·NCCH2C6H4OH]—which are useful models of the most complexes (G 5 ), (G 6 ) and (G 7 ) were also prepared and incorporated in amorphous silica. Their pyrolytic products were compared with those of more complex cyclotriphosphazene analogous. Interestingly, the pyrolysis of the nanocomposite [(O3SCF3)Ag(PPh3)(HOC5H4N)][SiO2] n affords the firstly-reported materials containing Ag2O along with SiO2 nanoparticles.