A series of rare earth biphenolate complexes of the general form [Ln(mbmp)(mbmpH)(thf)3] (Ln = Y (1), Nd (2), Gd (3), Dy (4), Er (5), Tm (6) and Lu (7)) have...

Several new trivalent dinuclear rare earth 2,2'methylenebis(6-tert-butyl-4-methylphenolate) (mbmp 2À ) complexes with the general form [Ln 2 (mbmp) 3 (thf) n ] (Ln = Sm 1, Tb 2 (n = 3), and Ho 3, Yb 4 (n = 2), and a tetravalent cerium complex [Ce(mbmp) 2 (thf) 2 ] (5) have been synthesised by RTP (redox transmetallation/protolysis) reactions from lanthanoid metals, Hg(C 6 F 5 ) 2 and the biphenol mbmpH 2 . These new complexes and some previously reported partially protonated rare earth biphenolate complexes [Ln(mbmp)(mbmpH)(thf) n ] react with lithium, aluminium, potassium and zinc organometallic reagents to form lanthanoid-main group heterobimetallic species. When reaction mixtures containing the Ln biphenolate complexes were treated with n-butyllithium, both molecular ([Li(thf) 2 Ln(mbmp) 2 (thf) n ] (Ln = La 6, Pr 7 (n = 2) and Er 8, Yb 9, and Lu 10 (n = 1)) and charge separated ([Li(thf) 4 ][Ln(mbmp) 2 (thf) 2 ] (Ln = Y 11, Sm 12, Dy 13, and Ho 14) complexes were isolated. Treatment with trimethylaluminium also led to isolation of molecular ([AlMe 2 Ln-(mbmp) 2 (thf) 2 ] (Ln = Pr 15, Sm 16, and Tb 17)) and ionic [La(mbmp)(thf) 5 ][AlMe 2 (mbmp)] ( 18) complexes. One gadolinium-potassium ([K(thf) 3 Gd(mbmp) 2 (thf) 2 ] ( 19)), and one ytterbium-zinc species ([ZnEtYb(mbmp) 2 (thf)] ( 20)) were isolated from treatment of reaction mixtures with potassium bis(trimethylsilyl)amide and diethylzinc respectively.

The synthesis of two new tetra- and penta-phenycyclopentadienyldiphenylphosphine pro-ligands which readily undergo selective C-P bond cleavage has allowed for the facile synthesis of bulky divalent octa- and deca-phenylmetallocenes of europium,...

Reductive dimerization of fulvenes using low-valent metal precursors is a straightforward one-step approach to access ethylene-bridged metallocenes. This process has so far mainly been employed with fulvenes carrying one or two substituents in the exocyclic position. In this work, a new synthesis of the unsubstituted exocyclic 1,2,3,4tetraphenylfulvene (1), its full structural characterization by NMR spectroscopy and singlecrystal X-ray diffraction, as well as some photophysical properties and its first use in reductive dimerization are described. This fulvene reacted with different lanthanoid metals in thf to provide the divalent ansa-octaphenylmetallocenes [Ln(C 5 Ph 4 CH 2 ) 2 (thf) n ] (Ln = Sm, n = 2 (2); Ln = Eu, n = 2 (3); and Ln = Yb, n = 1 (4)). These complexes were characterized by X-ray diffraction, laser desorption/ionization time of flight mass spectrometry, and, in the case of Sm and Yb, multinuclear NMR spectroscopy, showing the influence of the ansa-bridge on solution and solid-state structures compared to previously reported unbridged metallocenes. Furthermore, the luminescence properties of the Eu ansa complex 3 were studied in solution and the solid state, revealing significant differences with the known octa-and deca-phenyleuropocenes, [Eu(C 5 Ph 4 H) 2 (dme)] and [Eu(C 5 Ph 5 ) 2 ].

From the redox-transmetallation protolysis (RTP) reaction of europium metal, Hg(C6F5)2 and pentaphenylcyclopentadiene, we isolated and crystallographically characterised small amounts of the first divalent europium fluoride half-sandwich complex [Eu(C5Ph5)(μ-F)(thf)2]2 (1). Subsequently, a rational synthesis of this complex from in situ formed [EuF2(thf)n] and [Eu(C5Ph5)2] was carried out. In addition, the new divalent Eu alkoxide complex [Eu(OC5Ph5*)2(thf)4] (2) (OC5Ph5* = 2,3,4,5,5 pentaphenylcyclopenta-1,3-dienolate) was identified by X-ray diffraction analysis, in which an intriguing phenyl group migration in the cyclopentadiene ligand occurred. This complex was shown to be derived from small impurities of 1,2,3,4,5-pentaphenylcyclopenta-1,3-dienol (C5Ph5OH) in the C5Ph5H starting material and was then synthesised on a larger scale. Density functional theory calculations provided evidence for the facile phenyl group migration observed in the cyclopentadienolate ring.