Publications by authors named "Roesky H"

Reactions of LAl with ethyne, mono- and disubstituted alkynes, and diyne to aluminacyclopropene LAl[eta2-C2(R1)(R2)] ((L = HC[(CMe)(NAr)]2, Ar = 2,6-iPr2C6H3); R1 = R2 = H, (1); R1 = H, R2 = Ph, (2); R1 = R2 = Me, (3); R1 = SiMe3, R2 = C[triple bond]CSiMe3, (4)) are reported. Compounds 1 and 2 were obtained in equimolar quantities of the starting materials at low temperature. The amount of C2H2 was controlled by removing an excess of C2H2 in the range from -78 to -50 degrees C.

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Three novel aluminum-containing tin(IV) heterobimetallic sulfides are reported. The reaction of [LAl(SLi)2(THF)2]2 (1) [L = HC(CMeNAr)2, Ar = 2,6-iPr2C6H3] with Ph2SnCl2, Me2SnCl2, and SnCl4 in THF respectively afforded LAl(mu-S)2SnPh2 (2), LAl(mu-S)2SnMe2 (3), and LAl(mu-S)2Sn(mu-S)2AlL (4) in moderate yields. Compounds 2, 3, and 4 were characterized by elemental analysis, NMR, electron-impact mass spectrometry, and single-crystal X-ray structural analysis.

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The reaction of LAl[eta2-(C2(SiMe3)2)] (1; L = HC[(CMe)(NDipp)]2, Dipp = 2,6-iPr2C6H3) with dioxygen leads to the elimination of bis(trimethylsilyl)acetylene and the formation of the corresponding aluminum monohydroxide via the oxidation of one of the CHMe2 groups on the Dipp ring.

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A series of organometallic compounds of group 13 metals supported by the sterically encumbered beta-diketiminate ligand containing hydrides, fluorides, chlorides, and bromide have been synthesized and structurally characterized. The synthetic strategy applied utilizes halide metathesis and reduction of metal chlorides to the corresponding hydrides. Thus, the reaction of LLi.

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A series of Al(III) compounds containing the C6F5-substituted beta-diketiminate ligands LAlMeCl (2), LAlMe2 (3), LAlMeI (4), and LAlBr2 (5) (L = HC[(CMe)(NC6F5)]2) were synthesized and characterized. The hydrolysis of 2 and 4 in the presence of 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene as the hydrogen halide acceptor both lead to (LAlMe)2(mu-O) (6), a methylalumoxane derivative, which is the first hydrolysis product with the general formula of (RAlMe)(n)O. A comparison of the hydrolysis products of 2 and 4 with that of L'AlMeCl (L' = HC[(CMe)(NAr)]2, Ar = 2,6-iPr2C6H3) shows that with the C6F5-substituted beta-diketiminate ligand, it was not possible to generate LAlMe(OH).

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A monomeric hydroxide of gallium, LGa(Me)OH, containing terminal hydroxide and methyl groups was prepared by the hydrolysis of LGa(Me)Cl in the presence of N-heterocyclic carbene and water [L = HC{(CMe)(2,6-i-Pr2C6H3N)}2] in high yield and in a pure form. LGa(Me)OH was used as a synthon to assemble the first hetero-bimetallic compound with a Ga-O-Zr core, [(LGaMe)(Cp2ZrMe)](mu-O).

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W-Band EPR spectra of [[HC(CMeNAr)(2)]Mn](2) (Ar = 2,6-(i)Pr(2)C(6)H(3)) have been measured at different temperatures. The spectra show a behavior which is typical for an antiferromagnetically coupled dimer with excited states populating upon increasing temperature. By following the intensity variation of the different features of the spectra with temperature, we attributed different groups of resonances to the S = 1, 2, and 3 states of the dimer.

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A novel synthetic approach is given for the preparation of a metal-organic lanthanide sol-gel precursor solution and its application for the production of coated conductors. Besides all other problems concerning the technical process itself, the key to a successful deposition of oxide layers is the choice of the precursor solution and the understanding of the mechanism of deposition. Moreover, the isolation and characterization of the species involved in the reaction is very important.

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The cobalt(II) and iron(II) siloxane compounds were prepared by the reaction of lipophilic N-bonded silanetriol 1 with metal silylamides M[N(SiMe3)2]2 (M = Co (2), Fe (3)) in a 1:1 and 3:4 molar ratio, respectively. A plot of 1/chi versus temperature in the range of 2-300 K indicates the paramagnetic behavior of 2 and 3. The composition and molecular structures of 2 and 3 were fully determined by IR, elemental analysis, and X-ray crystal structural analyses.

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In this article, we discuss the synthesis of tetrameric and monomeric aluminium(I) compounds. These compounds are prepared by reduction of the respective Al-X (X = halide) bond containing precursor. The tetrameric aluminium(I) compounds are synthesized by using sterically bulky ligands whereas a stable monomeric aluminium(I) compound is obtained using a monovalent chelating ligand.

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The reactions of t-BuCCLi with a mixture of AlH(3).NMe(3) and ClAlH(2).NMe(3) in boiling toluene with the addition of [t-BuCH(2)(Bzl)NMe(2)]Cl, or a bulky beta-diketimine instead, and [n-Bu(4)N]Cl led to the carbaalanates [H(2)Al(NMe(3))(2)](2)[(AlH)(8)(CCH(2)t-Bu)(6)], 3, and [n-Bu(4)N](2)[(AlH)(8)(CCH(2)t-Bu)(6)], 4, respectively.

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Deprotonation of an Al-SH moiety has been achieved easily by using N-heterocyclic carbene as the base. Monomeric mono- and bis-imidazolium salts [C(t)H(+)][LAl(SH)(S)](-) ([C(t)H(+)] = N,N'-bis-tert-butylimidazolium), [C(m)H(+)][LAl(SH)(S)](-), and [C(m)H(+)](2)[LAl(S)(2)](2-) ([C(m)H(+)] = N,N'-bismesitylimidazolium), containing unusual anions [LAl(SH)(S)](-) and [LAl(S)(2)](2-), have been synthesized in nearly quantitative yields. Furthermore, [C(m)H(+)](2)[LAl(S)(2)](2-) has been successfully used for the preparation of LAl(SSiMe(2))(2)O containing the [O(Me(2)SiS)(2)](2-) ligand.

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An aluminum oxide [LAlO]2 (1) has been prepared by the oxidative addition of aluminum(I) monomer LAl (L = HC[(CMe)(NAr)]2, Ar = 2,6-iPr2C6H3) with molecular oxygen. The short Al-O bonds in Al2(mu-O)2 result in short Al..

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This paper reports on the synthesis, X-ray structure, magnetic properties, and DFT calculations of [[HC(CMeNAr)2]Mn]2 (Ar = 2,6-iPr2C6H3) (2), the first complex with three-coordinate manganese(I). Reduction of the iodide [[HC(CMeNAr)2]Mn(mu-I)]2 (1) with Na/K in toluene afforded 2 as dark-red crystals. The molecule of 2 contains a Mn2(2+) core with a Mn-Mn bond.

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Synthesis of a new class of compounds containing a Ln-O-Al moiety has been accomplished by the reaction of LAlOH(Me) (L = HC(CMeNAr)(2), Ar = 2,6-iPr(2)C(6)H(3)) with a series of Cp(3)Ln compounds. The terminal Al-OH group shows selective reactivity, and the complexes Cp(2)Ln(THF)-O-AlL(Me) (Ln = Yb, 1; Er, 2; Dy, 3), Cp(2)Yb-O-AlL(Me) (4), and Cp(3)Ln(mu-OH)AlL(Me) (Ln = Er, 5; Dy, 6; Sm, 7) were obtained. This allows further insight into the proton exchange process, and two different mechanisms, intermolecular and intramolecular elimination of CpH, are proposed under different conditions.

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Two novel germanium(II) mu-oxo heterobimetallic oxides with different oxidation states at the metal centers have been reported. The reaction of LGeOH [L = N(Ar)C(Me)CHC(Me)N(Ar) (Ar = 2,6-i-Pr(2)C(6)H(3))] with Cp(2)MMe(2) (M = Zr, Hf) in Et(2)O afforded LGeOM(Me)Cp(2) [M = Zr (2), Hf (3)] in moderate yield. Compounds 2 and 3 were characterized by elemental analysis, IR, NMR, EI-MS, and single X-ray structural analysis.

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An unprecedented aluminum hydroxide LAlMe(OH) (5; L = HC[(CMe)(2,6-iPr2C6H3N)]2) has been prepared by the hydrolysis of LAlMeCl (4). For the preparation of 5, the reagents of KOH, water, and KH, as well as the two-phase ammonia/toluene system, were used. Further reactions of 5 with Cp2ZrMe2 (8) and Cp2ZrHCl in toluene lead to the intermolecular elimination of CH4 and H2 and the formation of mu-O-bridged dinuclear aluminum and zirconium complexes [LAlMe(mu-O)ZrMeCp2] (6) and [LAlMe(mu-O)ZrClCp2] (7), respectively, in high yields.

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The reaction between beta-diketiminato-stabilized aluminum dihydride LAlH2 and tBuOOH leads to the formation of a pentacoordinated tert-butylperoxo aluminum compound.

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The synthesis of terminal hydroxide containing Group 13 and 14 metals [LAl(OH)(2)], LAlMeOH, [{LAl(OH)}(2)(mu-O)], LAl(OH)-O-AlLL', LGeOH, and [TsiSn(O)OH](3) [Tsi = (Me(3)Si)(3)C] has been accomplished using innovative synthetic methodologies. All of these compounds have been structurally characterized, both in solution as well as in the solid state. The utility of such metal hydroxides [{LAl(OH)}(2)(mu-O)] and LAlMeOH [L = HC{(CMe)(2,6-i-Pr(2)C(6)H(3)N)}(2)] in the preparation of homo- and heterometallic compounds has been demonstrated.

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