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The Schiff base NNO ligand 1-(furan-2-yl)-N-[(2-methyl-1H-imidazol-4-yl)methylene]methanamine was synthesized and structurally characterized by XRD crystallography, mass spectrometry, and NMR spectroscopy. Quantum-chemical calculations revealed conformational flexibility of the ligand backbone to give two different conformations with nearly equal ground-state energies. The orientation of two nitrogen atoms and the oxygen atom in one conformation is a good fit for the NNO tridentate coordination mode, whereas the other would allow the NN coordination mode only. Two lanthanide complexes [Ln(tta)3(NNO)] (Ln = EuIII and LuIII; tta = thenoyltrifluoroacetone) were prepared and studied spectroscopically. The structures of the complexes were optimized by the DFT approach. The NNO ligand in the Eu complex displays tridentate NNO coordination, whereas the ligand is only NN-coordinated in the Lu complex. The Eu complex shows bright red metal-centered phosphorescence under excitation into the ligand (π–π*) absorption bands with a quantum yield of ca. 80 % and a lifetime of 580 μs. A mechanism for energy transfer between the ligands and metal centers was suggested and confirmed by DFT and time-dependent DFT (TDDFT) studies. An organic light-emitting diode (OLED) device based on the Eu complex incorporated into a poly(9-vinylcarbazole) (PVK) matrix was prepared. A study of the characteristics of the device revealed electrochromism of the system owing to variations in the efficacy of metal-centered and matrix emission at different strengths of applied electric field.

The reactivity of neodymium diiodide, NdI2 (1), towards organosilicon, -germanium and -tin halides has been investigated. Compound 1 readily reacts with Me3SiCl in DME to give tri- methylsilane (6 %), hexamethyldisilane (4 %) and (Me3Si)2O (19 %). The reaction with Et3SiBr in THF results in formation of Et3SiSiEt3 (17 %) and Et3SiOBu n (34 %). Alkylation of Me3SiCl with Pr n Cl in the presence of 1 in THF affords Me3SiPr n (10 %), Me3SiOBu n (52 %) and Me3SiSiMe3 (1 %). The main product iden- tified in the reaction mixture formed upon interaction of 1 with dichlorodimethylsilane Me2SiCl2 in THF is di-n-butoxydimethyl- silane Me2Si(OBu n )2 (54 %) together with minor amounts of Me2Si(OBu n )Cl. The reaction of 1 with Me3GeBr under the same conditions produces Me3GeGeMe3 (44 %), Me3GeH (3 %), and Me3GeI (7 %). An analogous set of products was obtained in the reaction with Et3GeBr. Treatment of trimethyltin chloride with 1 causes reduction of the former to tin metal (74 %). Me3SnH (7 %) and hexamethyldistannane (11 %) were identified in the volatile products. The reaction of 1 with Me3SiI provides straightforward access to hepta-coordinated NdI3(THF)4 (2), the structure of which was determined by X-ray diffraction.

The reactions of anhydrous LnCl3 (Ln = Y, Nd, Sm, Lu) with two equiv. of sodium N,N′-dicyclohexyl-N′′-bis(trimethylsilyl)guanidinate Na[(Me3Si)2NC(NCy)2], obtained from Na[N(SiMe3)2] and the 1,3-dicyclohexyl-substituted carbodiimide CyN=C=NCy in THF, yield the monochloro bis(guanidinate) tetrahydrofuranate complexes [(Me3Si)2NC(NCy)2]2LnCl(THF) [Ln = Y (1), Nd (2), Sm (3) and Lu (4)]. The analogous reactions of YCl3 and LuCl3 with the lithium guanidinate [Li(Et2O)][(Me3Si)2NC(NCy)2] afford the bis(guanidinate) “ate” complexes [(Me3Si)2NC(NCy)2]2Ln(μ-Cl)2Li(THF)2 [Ln = Y (5) and Lu (6)]. Treatment of 5 with dimethoxyethane results in the formation of [(Me3Si)2NC(NCy)2]2Y(μ-Cl)2Li(DME) (7). The carbyl complexes [(Me3Si)2NC(NCy)2]2Y-tBu] (8), [(Me3Si)2NC(NCy)2]2Y(μ-Me)2Li(TMEDA) (10) and [(Me3Si)2NC(NCy)2]2YPh(THF) (13) were obtained by interaction of complex 1 with RLi (R = tBu, Me or Ph). The molecular structures of 1, 6, 7, 8 and the side product [Li(TMEDA)][(Me3Si)2NC(NCy)2] have been determined by single-crystal X-ray analyses. Agostic interactions between the yttrium atom and the tert-butyl group in complex 8 in the solid state as well as in solution have been substantiated by 13C NMR spectroscopy and X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Heating NdI2 (1) or DyI2 (2) with vanadocene (3) in benzene at 85 °C led to the formation of bis(benzene)vanadium in 10 and 24 % yields, respectively. The lanthanide products were isolated in the form of CpLnI2(THF)3 after crystallization from THF. The interaction of 2 with 3 in isopropylbenzene at 90 °C yielded a mixture of (arene)2V complexes from which a small amount of bis(isopropylbenzene)vanadium was isolated. The same reaction did not occur in mesitylene. From the reaction of 2 with 3 in molten naphthalene at 100 °C, the heterobimetallic cluster {[CpDy(μ-I)2]7Cp2V(μ-I)}(4) was isolated in low yield. The reaction of Cp2Cr with 1 or 2 in benzene at ambient temperature afforded the dimer [CpCr(μ-I)]2 (5) and a dysprosium complex, Cp2DyI (6) (in the reaction with 2). When the reaction with 2 was carried out at 80 °C, along with compound 6, the -ate complex {[Cp2DyI2]–[Cp2Cr]+}(7) was crystallized from the reaction solution. Nickelocene was reduced by 2 in benzene at 80 °C to nickel metal. The dysprosium product was isolated as solvent-free complex 6. Ferrocene and cobaltocene did not react with 1 and 2 in benzene. The molecular structures of compounds 4, 5, and 7 were characterized by X-ray diffraction analysis.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Arene complexes of divalent samarium, [(C6R6)Sm(AlCl3I)2]n (C6R6 = C6H5Me (1); C6Me6 (2)), were obtained by reaction of unsolvated SmI2 with AlCl3 in toluene and hexamethylbenzene. Crystallization of the tetrahalo-aluminate lanthanide arene complexes gave single crystals that showed disorder in the Cl and I positions by X-ray crystallography, but provided detailed information on η6-arene coordination to SmII. The more strongly reducing lanthanide diiodide TmI2 did not form analogous products under the same conditions, but the reaction of TmI2 with AlCl3 in toluene in the presence of naphthalene formed the trivalent arene complex (C6H5Me)Tm(AlCl4-xIx)3 (3).

The reactions of diamagnetic [(C9H7)2Yb(THF)2] (2) and [rac-(CH2-1-C9H6)2Yb(THF)2] (3) with tBuN=CH–CH=NtBu (DAD) in toluene result in the formation of the paramagnetic complexes [(C9H7)2Yb(DAD)] (4) and [rac-(CH2-1-C9H6)2Yb(DAD)] (5), respectively. The IR, UV/Vis, and 1H NMR spectroscopic data, the magnetic properties, and the single-crystal X-ray diffraction studies of 4 and 5 indicate that in the solid state and in noncoordinating media both complexes are ytterbium(III) derivatives containing the DAD radical-anion, whereas the 1H NMR and UV/Vis spectra of solutions of 4 and 5 in the coordinating solvent THF give evidence for divalent ytterbium. Recrystallization of 4 and 5 from THF/hexane results in the recovery of the starting ytterbium complexes 2 and 3 due to an unusual redox substitution of the radical anion of diazabutadiene by THF in the coordination sphere of ytterbium. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

The reaction of anhydrous LuCl3 with a twofold molar excess of lithium guanidinate [Li{(Me3Si)2NC(NiPr)2}], obtained in situ from the amide [LiN(SiMe3)2(Et2O)] and 1,3-diisopropylcarbodiimide in THF, yields the bis(guanidinate) “ate” complex [Lu{(Me3Si)2NC(NiPr)2}2(μ-Cl)2Li(THF)2] (1). The alkyllutetium derivative [Lu{(Me3Si)2NC(NiPr)2}2(CH2SiMe3)] (2) was synthesized by a metathesis reaction of 1 with LiCH2SiMe3 in toluene. The treatment of 2 with an equimolar amount of PhSiH3 in hexane at room temperature results in the first known dimeric lanthanide hydride in a bis(guanidinate) coordination environment, [Lu{(Me3Si)2NC(NiPr)2}2(μ-H)]2 (3). The crystal structures of complexes 1 and 3 have been determined by X-ray crystallography. The hydrido complex 3 was found to catalyze polymerization of ethylene, propylene and styrene. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

The reduced lanthanide iodides of the composition LnIx (Ln = Sc, Y, La, Ce, Pr, Gd, Ho, and Er; x < 3) were obtained by the reaction of an excess of the appropriate metal with iodine at high temperatures. The diamagnetism of the Sc, Y, and La derivatives indicates the trivalent state of the metals in these products. In contrast to the diiodides of Nd(II), Dy(II), and Tm(II), the isolated solids do not dissolve in THF, DME, or liquid ammonia. Despite of their insolubility in THF, all these products readily react in this medium with phenol or alcohols to give the corresponding phenoxy- or alkoxylanthanide diiodides ROLnI2(THF)x (R = Ph, i-C3H7, t-Bu; x = 2, 3, or 5) in yields up to 55 %. Their interactions with cyclopentadiene in THF afford the complexes CpLnI2(THF)3 with yields up to 60 %. From the reaction of LaIx with 2, 2'-bipyridine (bipy), the complex LaI2(bipy)2(THF)2 was isolated. Triphenylcarbinol, stilbene, naphthalene, and anthracene are inert towards the obtained substances. Reaktivitat der Lanthanoidiodide LnIx (x < 3) aus der Reaktion von Lanthanoidmetallen mit Iod Die „reduzierten” Lanthanoidiodide LnIx mit x < 3 (Ln = Sc, Y, La, Ce, Pr, Gd, Ho, Er) wurden durch Reaktion eines Uberschusses des entsprechenden Metalls mit Iod bei hohen Temperaturen erhalten. Der Diamagnetismus der erhaltenen Sc-, Y- und La-Praparate zeigt, dass die Metalle darin dreiwertig sind. Im Gegensatz zu den Diiodiden von NdII, DyII und TmII losen sich die isolierten Substanzen nicht in THF, DME oder flussigem Ammoniak. Trotz ihrer Unloslichkeit in THF reagieren die Praparate darin mit Phenol oder Alkoholen leicht zu den entsprechenden Phenoxi- bzw. Alkoxilanthanoiddiiodiden ROLnI2(THF)x (R = Ph, iC3H7, tBu; x = 2, 3 oder 5) in Ausbeuten bis zu 55 %. Die Umsetzungen mit Cyclopentadien in THF ergibt die Komplexe CpLnI2(THF)3 in Ausbeuten bis zu 60 %. Aus der Umsetzung von LaIx mit 2, 2'-Bipyridin (bipy) wurde der Komplex LaI2(bipy)2-(THF)2 erhalten. Triphenylcarbinol, Stilben, Naphthalin und Anthracen reagieren mit den erhaltenen Praparaten nicht.

The data on the synthesis and physicochemical and photo- and electroluminescent properties of carbochain linear polymers containing ions of rare-earth metals bound via chemical or coordination bonds to the polymer chain are summarized. The effects of the ligand environment at lanthanide atoms and the structures of the polymers on their luminescence activity are considered. Possible approaches to increase the efficiency of electroluminescence of polymer lanthanide emitters are discussed.

The reaction of the naphthalene ytterbium(II) complex (µ-C10H8)[YbI(DME)2]2 (1) with indene proved to be a convenient synthetic route to the novel indenyl half-sandwich ytterbium(II) complex [(C9H7)YbI(DME)2] (2), which is a monomer in the solid state and stable in DME solution, although it rearranges in THF to give the symmetric derivatives [(C9H7)2Yb(THF)2] and [YbI2(THF)2]. The reaction of 2 with equimolar amounts of C5H5Na in DME yields [(C5H5)2Yb(DME)] and [(C9H7)2Yb(DME)].

Organolanthanoids of several classes were examined as potential styrene and propene polymerization catalysts. They are: molecular hydrides of divalent lanthanoids (samarium, europium, ytterbium); naphthalene and stilbene complexes of neodymium(III), samarium(II), europium(II), ytterbium(II), lutetium(III); amides and alkoxides (including heterobifunctional derivatives) of praseodymium(III), neodymium(III), samarium(II), europium(II), thulium(III), ytterbium(II, III); thiolate of samarium(III); phenyl and phenylethinyl derivatives of europium(II), thulium(III), ytterbium(II); methylytterbium cluster Yb8 (μ-CH3)14(μ-CH2)(THF)6; heterobimetallic samarium(II), ytterbium(II, III) complexes; diazabutadiene ytterbium(III) derivatives; metallic praseodymium and ytterbium, activated by iodine. The highest activity in styrene polymerization revealed hydrides, naphthalene and stilbene complexes of samarium(II), europium(II) and ytterbium(II). In the propene polymerization only [(η5-C5H4)CH2CH­(CH2OBu)(η1-O)]YbMe(THF) displayed noticeable activity.Copyright © 2001 John Wiley & Sons, Ltd.

Two new starting materials for a new chemistry of low-valent lanthanide compounds are the first crystallographically characterized molecular complexes of the rare Nd2+ ion, [NdI2 (thf)5 ] (1), and [TmI2 (thf)(dme)2 ] (2; dme=1,2-dimethoxyethane). These have a pentagonal-bipyramidal structure in which the two iodine atoms are in axial positions.

The metal–organic complexes of Sc, Y, La and lanthanides, which were tested as luminescent materials in organic light emitting diodes (OLEDs), are collected. The performances of the devices are given. Advantages and drawbacks of organic derivatives of rare earth metals as emissive materials are considered.

Samarium monosulfide in a state amorphous to X-rays was prepared by the successive interaction of lithium naphthalenide with samarium diiodide and a solution of sulfur in THF in inert atmosphere or under reduced pressure under standard (normal) conditions. Samarium monosulfide was transferred to the polycrystalline state (a=5.95 A, NaCl-like structure) by annealing in a vacuum (

Mikhail N. Bochkarev ;a, Marina A. Katkovaa, Elena A. Fedorovaa, Natalya P. Makarenkoa, Herbert Schumann ;b, Frank Girgsdiesb a G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Tropinina 49, 603600 Nizhny Novgorod GSP-445 (Russian Federation) b Institut fur Anorganische und Analytische Chemie der Technischen Universiẗat Berlin, Strase des 17. Juni 135, D-10623 Berlin (Deutschland)

The reactions of phthalonitrile with MeNH2, PrnNH2, and PriNH2 in the presence of catalytic amounts of LnI3 (Ln = Nd or Dy) or LnI3(THF)3 (Ln = Gd or Nd) afford 1,3-bis(alkylimino)isoindolines (Alk = Me (1), Prn (2), or Pri (3), respectively). Under analogous conditions, 2-aminopyridine gives 1,3-bis(2-pyridylimino)isoindoline (4). The X-ray diffraction study of compound 3 showed that, in the crystalline state, this compound exists as the isomer, 1-isopropylamino-3-(isopropylimino)isoindole.

Heating a mixture of the appropriate metal with iodine, followed by dissolving the products in THF or DME, and crystallization at low temperature has provided a simple route to microcrystalline molecular iodides of neodymium(II) and dysprosium(II), LnI2(THF)5 and LnI2(DME)3 (Ln=Dy, Nd). Prolonged drying of DyI2(THF)5 in vacuum yielded a violet powder of composition DyI2(THF)3. These crystalline complexes are thermally stable, but in the solution their stability is lower.

Die Zwei-Elektronen-Reduktion von 2,2′-Bipyridin mit Ytterbiumnaphthalin fuhrt zur Bildung des Ytterbiumkomplexes [{Yb(μ2-bipy)(thf)2}3], in dem antiaromatische 2,2′-Bipyridin-Dianionen die Ytterbiumatome in einer neuartigen μ2-η2:η4-Weise verbrucken.

Data on lanthanide coordination compounds with organic ligands used in the design of electroluminescent diodes are summarised and systematically represented. The molecular and electronic structures and spectroscopic characteristics of these compounds are considered. A comparative analysis of the properties of organic electroluminescent diodes with different compositions of emitting and conductive layers is presented.

Data on syntheses, structures and reactivities of scandium, yttrium, lanthanum and lanthanide complexes with π-bonded ligands containing one or several six-membered aromatic rings are surveyed and systematised. The bibliography includes 107 references.

Thulium diiodide reduces cyclic aromatic hydrocarbons that have reduction potentials more positive than - 2.0 V versus SCE. Thus, TmI2 reacts with cyclooctatetraene or acenaphthylene in THF, or with lithium anthracenide in 1,2-dimethoxyethane (DME) to give thulium triiodide and the thulium(III) complexes [(eta8-C8H8)TmI(thf)2] (1), rac-ansa-[(eta5-C12H8)2TmI(thf)] (2), or [(eta2-C14H10)TmI-(dme)2] (3), respectively. The molecular structures of 1-3 were determined by single-crystal X-ray diffraction.

Die Reaktion der Ge-Verbindung (I) mit metallischem Praseodym liefert den neuen Titelkomplex (II), fur den ionische Struktur angenommen wird.

The treatment of Cp2Yb, Cp3Sm, CeCl3, Cp3Ce, and Cp3Eu·THF with excess naphthalenesodium in THF gives systems capable of reducing molecular nitrogen at 20°C and atmospheric pressure with the formation of ammonia after hydrolysis.

Hexakis(pentafluorophenyl)digermane has a high reactivity that is not inherent to hexaphenyldigermane. The Ge−Ge bond in this compound is easily cleaved by water, methanol, ethylmercury chloride, and other compounds. The reactions proceed in either THF or acetone medium and fail to take place in nonpolar solvents.