Titanium Phosphonate Porous Materials Constructed from Dendritic Tetraphosphonates

摘要

An organic-inorganic hybrid material,TPPhA-Ti,was constructed by non-hydrolytic condensation of a dendritic tetrakis-1,3,5,7-(4-phosphona-tophenyl)adamantane precursor and ti-tanium(IV)isopropoxide.One preparative pathway yielded insoluble materials with a Ti/P ratio of approx1 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 approx 13 A;mesopores approx 38 A)with a high surface area,approx 550m~2g~(-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 approx 3.4.Both TEM and SEM revealed that hollow nanospheres were formed with diameters of approx 180-300 nm.