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 ∼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 (micropores ∼13 Å; mesopores ∼38 Å) with a high surface area, ∼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 ∼3.4. Both TEM and SEM revealed that hollow nanospheres were formed with diameters of ∼180–300 nm.