Carbon nitride materials have extraordinary potential in various applications, including catalysts, filled-particles, and superhard materials. Carbon nitride nanoclusters have been prepared under mild solvothermal conditions by a reaction between 1,3,5-trichlotriazine and sodium azide in toluene. The bulk material formed has a C(3)N(4) composition and consists of spheres with diameters ranging from approximately 1 nm to 4 mum. Nanometer-sized clusters of C(3)N(4) stoichiometry have been isolated on surfaces by sublimation or simple physicochemical methods. The clusters have then been characterized by atomic force microscopy and X-ray photoelectron spectroscopy. The laser desorption ionization mass spectra show peaks assignable to the C(12)N(16), C(21)N(28), and C(33)N(44) molecules which could correspond to cage structures with 4, 7, and 11 units of the C(3)N(4) subunit, respectively. The structure and stability of these new nitrogen-rich carbon nitride nanocages has been investigated using density functional theory calculations.