Highly active double metal cyanide complexes:: Effect of central metal and ligand on reaction of epoxide/CO2

Various novel double metal cyanide (DMC) catalysts were successfully prepared by modifying the central metal (M) and one of cyanide ion (CN-) in Zn-alpha[M(CN)(b)](c) complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction Of PO/CO2. Zn-Ni(II) DMC is a potential catalyst for alternating copolymerization Of PO/CO2, and DMC catalysts based on Zn-3[Co(CN)(5)X](2) (X = Br- and N-3(-)) exhibit moderate efficiency for the production of polycarbonates. This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand. (C) 2007 Guo Rong Qi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.