Indium complexes incorporating bidentate substituted pyrrole ligand:: Synthesis, characterization, and ring-opening polymerization of ε-caprolactone

The reactions of InCl3 with two and three equivalents of lithium (2-dimethylaminomethyl)pyrrolate (1) in diethyl ether solutions afford In[C4H3N(CH2NMe2)](2)CI (2) and III [C4H3N(CH2NMe2)](3) (3) in 92% and 50% yield, respectively. Subsequent reactions of 2 with MeLi and Li(C equivalent to CPh) yield In[C4H3N(CH2NMe2)](2)Me (4) and In[C4H3N(CH2NMe2)](2)(C equivalent to CPh) (5), respectively. All compounds were confirmed by H-1 and C-13 NMR spectroscopy and compounds 3, 4, and 5 were further characterized by single-crystal X-ray crystallography. Compounds 2, 3, and 4 showed moderate catalytic activity toward the ring-opening polymerization of E-caprolactone. (c) 2005 Elsevier B.V. All rights reserved.