Titanium phosphonate porous materials constructed from dendritic tetraphosphonates

An organic-inorganic hybrid material, TPPhA-Ti, was constructed by non-hydrolytic condensation of a dendritic tetrakis-1,3,5,7-(4-phosphonatophenyl)adamantane precursor and titanium((IV)) isopropoxide. One preparative pathway yielded insoluble materials with a Ti/P ratio of similar to 1 which was confirmed by a combination of FT-IR, TGA, and EDS measurements. N-2 sorption experiments showed that TPPhA-Ti is a porous solid (micro-pores similar to 13 angstrom; mesopores similar to 38 angstrom) with a high surface area, similar to 550 m(2)g(-1). The structure and morphology of the TPPhA-Ti as investigated by transmission and scanning electron microscopy showed a layered-type material. Additional X-ray diffraction data suggest a paracrystalline material; an optimization of possible molecular arrangements of TPPhA-Ti was simulated that was in agreement with the experimental data. A second preparative pathway yielded a Ti oxide-phosphonate with a Ti/P ratio of similar to 3.4. Both TEM and SEM revealed that hollow nanospheres were formed with diameters of similar to 180-300 nm.