New dinuclear bis(cyclopentadienyl)lanthanoid chlorides containing η5-C5H4 ligands linked by a metal-coordinated 2,6-dimethylenepyridyl unit
                                
                                    
                                        作者:Gino Paolucci、Rocco D'Ippolito、Changqing Ye、Changtao Qian、Jens Gräper、Dieter R. Fischer                                    
                                    
                                        DOI:10.1016/0022-328x(94)88112-x
                                    
                                    
                                        日期:1994.5
                                    
                                    The salts M2[2,6-(CH2C5H4)2C5H3N] (i.e. Na2L, Li2L) react under mild conditions with anhydrous LnCl3 in the molar ratio 1:1 to afford complexes 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 suggest that L is chelating and not metal-bridging. Direct coordination of the pyridine-N atom to the Ln ion has been deduced from XPS measurements. Reaction of PrCl3.(THF)x and Na2L in the molar ratio 2:3 leads to the compound [L3Pr2](9) which has been characterized by elemental analysis, 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.