A novel liquid/solid two-phase reaction has been discovered that enables destruction of a series of low-molecular-weight chloro-/bromo-hydrocarbons to carbon-based materials. The solid phase is anhydrous potassium hydroxide and the liquid phase is a benzene or tetrahydrofuran solution of halide and contains a certain amount of tetrabutyr ammonium bromide (TBAB) as phase transfer catalyst. The structure of the carbon-based materials have been characterized by elemental analysis, Fourier transform infrared (FT-IR), FT-Raman, and X-ray photoelectron spectroscopies, and their morphologies have been examined by wide-angle X-ray diffraction and transmission electron microscopy. The results indicate that the products are amorphous nanoparticles and contain mainly elemental carbon. They consist of sp, sp(2), and sp(3) carbon atoms simultaneously and can be regarded as carbyne analogues. This work provides a convenient method for synthesizing new carbon-based materials in relatively high yields. (C) 2000 John Wiley & Sons, Inc.