Globular Porous Nanoparticle Tin(IV) Phenylphosphonates and Mixed Methyl Phenylphosphonates

Hydrothermal synthesis of Sn(O3PC6H5)2 yields globular aggregates of nanoparticles that are layered. The particle size depends upon the time and temperature of hydrothermal treatment but may be as small as 20 nm in the lateral directions and three or four layers thick. Because of their small size, the particles form globules within which the particles form “house of cards” type pores. Surface areas as high as 300 m2/g are common with pores in the micropore range. Tin(IV) methylphosphonate is also layered, but the particles tend to aggregate into rosettes. Mixed derivatives of the type Sn(O3PC6H5)x(O3PCH3)2-x, where x > 0.5, also form globules, with higher surface areas than the tin phenylphosphonates. The formation of these spherical aggregates appears to be general for tin(IV) phosphonates as a result of a lack of particle growth.