Details

Autor(en) / Beteiligte

• Chakraborty, Debashis
• Chen, Eugene Y.-X

Titel

Neutral, Three-Coordinate, Chelating Diamide Aluminum Complexes:  Catalysts/Initiators for Synthesis of Telechelic Oligomers and High Polymers

Ist Teil von

• Organometallics, 2002-04, Vol.21 (7), p.1438-1442

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2002

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Reaction of the bulky chelating diamine ligand ArNH(CH2)3NHAr (Ar = 2,6-iPr2C6H3) with AlMe3 cleanly affords the monomeric, three-coordinate, chelating diamide aluminum complex [N∩N]AlMe (1). The isobutyl derivative [N∩N]AliBu (2) is prepared in the same manner using triisobutylaluminum. The Al/B alkyl/aryl ligand exchange between 1 and B(C6F5)3 in refluxing toluene cleanly produces the pentafluorophenyl-substituted derivative [N∩N]AlC6F5 (3). Studies of model reactions between 1 and ε-caprolactone as well as analyses of low-molecular-weight oligomers demonstrate the ability of 1 to produce telechelic oligomers. At high monomer/initiator ratios, all three complexes are active for ring-opening polymerization of ε-caprolactone and cyclohexene oxide, producing high-molecular-weight polymers. The isobutyl derivative 2 exhibits the highest activity for both polymerizations in this catalyst series and produces poly(ε-caprolactone) having a number-average molecular weight over 1,000,000 Da.