Synthesis of 2,6-dialkoxylphenyllanthanoid complexes and their polymerization catalysis

The 1:1-2:1 reaction of [2,6-((PrO)-Pr-i)(2)C6H3]Li with anhydrous SmCl3 in THF gave [2,6-((PrO)-Pr-i)(2)C6H3](3) Sm 1 exclusively, while the 3:1 reaction gave [2,6-((PrO)-Pr-i)(2)C6H3](4)SmLi 2 as major product, which crystallizes in the monoclinic space group C2/c(No. 15) with a = 47.52(1) Angstrom, b = 11.680(9) Angstrom, c = 18.862(9) Angstrom, beta = 112.19(3)degrees, V= 9694(8) Angstrom(3), Z = 8, R = 0.077 and R-w = 0.074. In a similar manner, [2,6-((PrO)-Pr-i)(2)C6H3](3)La was obtained by reacting with LaCl3(THF)(2). The 2:1 reaction of [2,6-((PrO)-Pr-i)(2)C6H3]Li with YbCl3 gave [2,6-((PrO)-Pr-i)(2)C6H3](2)YbCl, which produces [2,6-((PrO)-Pr-i)(2)C6H3]Yb-2[CH(SiMe3)(2)](2)Li 4 by reaction with (SiMe3)(2)CHLi. Polymerizations of epsilon-caprolactone and alkyl isocyanates were examined using the resulting complexes. (C) 1998 Elsevier Science S.A. All rights reserved.