The chemical formation of advanced ceramics from organometallic precursors is promising with respect to structural design and tailormade properties. We report on the synthesis of nanocrystalline titanium carbonitride materials at different pyrolysis temperatures via the polymer-to-ceramic transformation of synthesised poly(titanylcarbodiimides) and their structural and nanochemical characterization using high-resolution and analytical electron microscopy, in combination with quantummechanical calculations. Pyrolysis at 800 degreesC leads to a mixture of amorphous carbon and titanium nitride as crystalline particles of about 4 nm in size. Pyrolysis at 1100 degreesC yields titanium carbonitride as crystalline particles of 20-30nm in size. The identification of all phases was possible by the analysis of the measured energy-loss near-edge spectra of their C-K and N-K edges, and comparison with measured standards and with simulated fine structures using calculations based on the density functional theory. (C) 2003 Elsevier Science B.V. All rights reserved.