Preparation of Nanoporous Inorganic–Organic Hybrids Containing Zirconium and Asymmetrically Linking O3P–C6H4–SiO3 Unit

Abstract

Inorganic–organic hybrid materials composed of [O3P–C6H4–SiO3] units and zirconium hydrothermally prepared in the presence of cationic surfactant showed nanoporosity and considerably high specific surface area.

Mesoporous Zirconium Phenylenesiliconate‐phosphonate Hybrids with Ordered Lamellar Nanostructures

“…The EDX results for p ZrPS‐2 indicate that the molar ratio of Zr/P/Si is close to 2:1:1, which supports the idea that the Zr/PPS ratio of the starting mixtures is almost retained through the hydrothermal synthesis, as previously found for ZrPS‐1b 6. In the case of p ZrPS‐2 prepared from starting mixtures with higher Zr contents (Zr/PPS‐E of 3 and 4), the compositions of the starting mixtures are also retained.…”

“…If the PC bonds of the PPS units are cleaved, the resulting zirconium phosphate species should give 31 P signals at around δ =−15 to −30 ppm,13 which would indicate negligible cleavage of the PC bonds in p ZrPS‐2. Differently from ZrPS‐1b, which gives a broad signal at around δ =0 ppm,6 the coordination environment of the phosphonate groups in p ZrPS‐2 is probably more specified like those of the above‐mentioned crystalline zirconium arylphosphonates. Compared with ZrPS‐2ns, the higher field peak is more intense for ZrPS‐2.…”

“…This will not be favorable for stable lamellar alignment of C 16 TA cationic molecules and formation of stable pillars in m ZrPS‐2. Preparation in a procedure similar to that of ZrPS‐1a6 by using p PPS‐H, which is the hydrolysis product of p PPS‐E with concentrated HCl, as the PPS source also gave well‐ordered lamellar products close to p ZrPS‐2. In this case, however, the periodicity of the materials was considerably deteriorated on heating at 300 °C.…”

“…Our interest is focused on the use of such asymmetrically linked organic units to form inorganic–organic hybrid ordered nanostructures. Recently, we succeeded in the preparation of novel 2D hexagonally ordered organic–inorganic hybrid mesostructures APS‐15 and ZrPS‐1a6 (originally denoted as ZPS but hereafter changed to ZrPS to avoid confusion with zinc‐containing compounds) that contained 4‐[O 3 PC 6 H 4 SiO 3 ] ( p PPS) units with aluminum or zirconium sources, respectively, in the presence of alkyltrimethylammonium bromide (C n TAB; n =12–18; n =16 unless otherwise stated) surfactants. This asymmetrically linking molecular component has not been used before as a main building unit for hybrid mesostructures as far as we are aware.…”

“…Surfactant removal from APS‐1 and ZrPS‐1a resulted in destruction of the ordered mesostructures, whereas the occluded surfactants in ZrPS‐1b, which was prepared from 4‐(EtO) 2 OPC 6 H 4 Si(OEt) 3 ( p PPS‐E) in a modified version of the procedure for ZrPS‐1a, were removed by calcination at 250 °C. Although the calcined ZrPS‐1b contained mesopores of around 2 nm, it showed poor structural order and considerable shrinkage of the as‐prepared mesostructure 6…”