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

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 pydcH 2 (pyridine‐2,6‐dicarboxylic acid) in a KOH solution of dmf at 343 K. Impregnation with a solution of the organometallic precursor [Mo(CO) 3 I 2 (NCCH 3 ) 2 ] led to substitution of the nitrile groups by two pyridine ligands. All the materials were characterized by powder X‐ray diffraction, FTIR, and 13 C CP MAS and 27 Al MAS solid‐state NMR spectroscopy. Similar Mo II complexes were also prepared by using pycH or pydcH 2 and characterized by elemental analysis as well as FTIR and 1 H and 13 C 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)