Silicon imido nitride with a specific surface area up to 1000 m(2) g(-1) is obtained by ammonolysis of silicon tetrachloride in organic solvents and subsequent NH4Cl removal at elevated temperatures in a stream of anhydrous ammonia. The material has a remarkably narrow pore size distribution and a mean pore size of 5.7 nm. TEM investigations reveal the spherical macromorphology and uniform dendritic mesostructure of the micrometer sized particles. A high number of Si-NH2 groups on the inner surface of the material is indicated from IR measurements. Si-29 MAS NMR indicates the presence of SiN48- tetrahedra.