Synthesis and Characterization of Homoleptic Lanthanide Guanidinate Complexes and Their Catalytic Activity for the Ring-Opening Polymerization of Trimethylene Carbonate

✍ Scribed by Liying Zhou; Yingming Yao; Yong Zhang; Mingqiang Xue; Jinglei Chen; Qi Shen

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 134 KB
• Volume: 2004
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200300856

✦ Synopsis

Abstract

Two methods to synthesize homoleptic guanidinate lanthanide complex are described. The samarium guanidinate complex [Sm{Ph~2~NC(NCy)~2~}~3~]·2C~7~H~8~ (1) can be synthesized by the metathesis reaction of lithium guanidinate with anhydrous samarium trichloride in a 3:1 molar ratio. The analogous complexes [Ln{Ph~2~NC(NCy)~2~}~3~]·2C~7~H~8~ [Ln = Yb (2), Nd (3)] can also be synthesized by the insertion reaction of N,N′‐dicyclohexylcarbodiimide into the Ln−N bond of [(THF)~4~Li][Ln(NPh~2~)~4~] in a 3:1 molar ratio in good yield. Complexes 1−3 were characterized by elemental analysis, IR and ^1^H NMR spectroscopy. The molecular structures of complexes 1 and 3 were further determined by X‐ray diffraction techniques. These complexes showed high activity for the ring‐opening polymerization of trimethylene carbonate (TMC), giving polymers with M~w~/M~n~ ranging from 1.41−1.73. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)