Comment on "Structure of a novel form of carbon: dehydropolycondensed adamantane?" by J. S. Rigden, K. J. Koivusaari, R. J. Newport, D. A. Green, G. Bushnell-Wye and J. Tomkinson, J. Mater. Chem. 1996, 6, 449.

This comment addresses the identification of the crystalline phase observed after Wurtz-Fittig coupling (using sodium) and heat treatment of 1,3,5,7-tetrabromoadamantane in J. S. Rigden, K. J. Koivusaari, Robert J. Newport, D. A. Green, G. Bushnell-Wye and J. Tomkinson, J. Mater. Chem. 1996, 6, 449, where a preparation intended to yield "dehydropolycondensed adamantane" (V. I. Kasatochkin, Y. P Kudryavtsev, V. M. Elizen, O. I. Egorova, A. M. Sladkov and V. V. Korshak, Dokl. Akad. Nauk. USSR 1976, 231, 1358) was re-investigated. Using powder X-ray diffraction (P-XRD), the crystalline phase in question was assigned by Ridgen et al. in 1996 to be a carbon-based "graphitic" material. We show here that this assignment is incorrect. A direct comparison of the P-XRD pattern reported in 1996 with the P-XRD pattern generated from the sodium bromide structure reveals that the crystalline phase observed is in fact sodium bromide (NaBr).