NEW DINUCLEAR BIS(CYCLOPENTADIENYL)LANTHANOID CHLORIDES CONTAINING ETA-5-C5H4 LIGANDS LINKED BY A METAL-COORDINATED 2,6-DIMETHYLENEPYRIDYL UNIT

The salts M2[2,6-(CH2C5H4)2C5H3N] (i.e. Na2L, Li2L) react under mild c onditions with anhydrous LnCl3 in the molar ratio 1:1 to afford comple xes of the type [(LLnCl)2] (Ln = Y, Pr, Nd, Sm, Dy, Er, Yb, or Lu; 1-8 ). The dinuclear nature of the products 1-8 has been confirmed by mass spectrometry. Extended B/E-linked scans of metastable transitions sug gest that L is chelating and not metal-bridging. Direct coordination o f the pyridine-N atom to the Ln ion has been deduced from XPS measurem ents. Reaction of PrCl3.(THF)x and Na2L in the molar ratio 2:3 leads t o the compound [L3Pr2](9) which has been characterized by elemental an alysis, H-1 NMR and mass spectrometry. Some preliminary results on the catalytic activity of 1-8 during hydrogenation of 1-hexene by LiAlH4 suggest the formation of catalytically active, intermediate hydrides.