Anchoring of organic molecules onto activated carbon

Three organic compounds with two different functionalities have been anchored to activated carbons, in order to assess their use either as potential coupling agents for metal complexes or as model for grafting metal complexes with the same functionalities. The selected compounds were cyanuric chloride and 5-chloro-1-phenyl-1H-tetrazole, which have chlorine atoms and 1,2-phenylenediamine with an amine group. The supports were activated carbons derived from coconut shell charcoal, which were oxidised, either with oxygen (5% in a mixture of nitrogen and air) or with concentrated nitric acid, to increase selectively the amount of surface functional groups. Additional treatment with LiAlH4 took place before anchoring chlorine containing molecules, and the anchoring of 1,2-phenylenediamine was preceded by reaction with thionyl chloride to enable formation of amide bonds with the amine. Compelling evidence for the anchoring of these compounds onto the activated carbons was provided by the characterisation of these new materials using temperature-programmed reduction, temperature-programmed desorption and X-ray photoelectron spectroscopy. (C) 2001 Elsevier Science B.V. All rights reserved.