Pyridine Carboxylate Complexes of MoII as Active Catalysts in Homogeneous and Heterogeneous Polymerization

• Published in: European Journal of Inorganic Chemistry Vol. 2007; no. 18; pp. 2917 - 2925
• Main Authors: Vasconcellos-Dias, Maria, Nunes, Carla D., Vaz, Pedro D., Ferreira, Paula, Calhorda, Maria José
• Format: Book Review
• Language: English; Japanese
• Published: Weinheim WILEY-VCH Verlag 01.06.2007; WILEY‐VCH Verlag
• Subjects: Catalysis; Heptacoordination; Lamellar materials; Molybdenum; Polymerization; ROMP
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.200700091

New lamellar materials intercalated with molybdenum(II) complexes with potential catalytic properties were prepared by a stepwise procedure. The lamellar material was first calcined at 823 K for four hours to eliminate all the carbonate ions; the layered structure was reconstructed after treatment with a solution of either pycH (pyridine‐2‐carboxylic acid) or pydcH2 (pyridine‐2,6‐dicarboxylic acid) in a KOH solution of dmf at 343 K. Impregnation with a solution of the organometallic precursor [Mo(CO)3I2(NCCH3)2] led to substitution of the nitrile groups by two pyridine ligands. All the materials were characterized by powder X‐ray diffraction, FTIR, and 13C CP MAS and 27Al MAS solid‐state NMR spectroscopy. Similar MoII complexes were also prepared by using pycH or pydcH2 and characterized by elemental analysis as well as FTIR and 1H and 13C solution NMR spectroscopy. These new materials and the complexes of pyc or pydc ligands containing 4.54 wt.‐% and 6.33 wt.‐% of Mo respectively, catalyze the ring‐opening‐metathesis polymerization of norbornene and the polymerization of styrene at 333 K, their performance increasing upon the addition of methylalumoxane (MAO) as cocatalyst.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)