12076-08-3Relevant articles and documents
Lewis base complexes of AlH3: Structural determination of monomeric and polymeric adducts by X-ray crystallography and DFT calculations
Humphries, Terry D.,Munroe, Keelie T.,Decken, Andreas,McGrady, G. Sean
, p. 6953 - 6964 (2013)
The AlH3 adducts of TMEDA (Me2NCH2CH 2NMe2), DIOX (O(CH2CH2) 2O), TEA (Et3N), BDMA (PhNMe2), and TMPDA (Me2NCH2CH2CH2NMe2) have each been characterised by single-crystal X-ray diffraction at low temperature, by 1H, 14N and 27Al NMR and FT-Raman and FT-IR spectroscopy, and by DFT calculations and elemental analysis. Hence, AlH 3·TMEDA and AlH3·DIOX are both shown to adopt a polymeric structure, with the bidentate ligand bridging two Al centres, each of which adopts a trigonal bipyramidal (TBP) arrangement with equatorial hydride moieties. The 1 : 2 adduct AlH3·2BDMA is monomeric but the geometry at the Al centre resembles closely that of the polymeric TMEDA and DIOX complexes. AlH3·TEA alone adopts a monomeric structure in which the Al centre is tetrahedrally coordinated by three hydride and one amine ligand. The Al-L bond distance of 2.0240(17) A for AlH 3·TEA is the shortest of all the complexes in this study, and AlH3·TEA also possesses the shortest Al-H bonds. AlH 3·DIOX has the shortest Al-L bond distance of the polymeric species (2.107(14) A) on account of the higher electronegativity of the oxygen donor. The structure of AlH3·TMEDA was determined at low temperature (monoclinic space group P21/c), and salient features are compared to the previous room temperature study, for which a highly disordered orthorhombic space group (P212121) was reported. The polymeric structures appear to be stabilised by a number of intermolecular interactions and unconventional hydrogen bonds; these are most pronounced for AlH3·DIOX, whose chains are connected by highly directional C-H...H-Al bonding with an H...H distance of 2.32(6) A. The Royal Society of Chemistry 2013.
Deaggregation of Zinc Dihydride by Lewis Acids including Carbon Dioxide in the Presence of Nitrogen Donors
Ritter, Florian,Morris, Louis J.,McCabe, Karl N.,Spaniol, Thomas P.,Maron, Laurent,Okuda, Jun
supporting information, p. 15583 - 15592 (2021/10/20)
Thermally sensitive polymeric zinc dihydride [ZnH2]n can conveniently be prepared by the reaction of ZnEt2 with [AlH3(NEt3)]. When reacted with CO2 (1 bar) in the presence of chelating N-donor ligands Ln = N,N,N′,N′-tetramethylethylenediamine (TMEDA), N,N,N′,N′-tetramethyl-1,3-propanediamine (TMPDA), N,N,N′,N″,N′′-pentamethyldiethylenetriamine (PMDTA), and 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane (Me4TACD), insertion into the Zn-H bond readily occurred. Depending on the denticity n, formates [(Ln)Zn(OCHO)2] were isolated and structurally characterized, either as a molecule (Ln = TMEDA, TMPDA, PMDTA) or a charge-separated ion pair [(Ln)Zn(OCHO)][OCHO] (Ln = Me4TACD). The reaction of [ZnH2]n with the mild Lewis acid BPh3 in the presence of chelating N-donor ligands Ln gave a series of hydridotriphenylborates, either as a contact ion pair [(L2)Zn(H)(HBPh3)] (L2 = TMEDA, TMPDA) or a separated ion pair [(Ln)Zn(H)][HBPh3] (Ln = PMDTA, Me4TACD). In the crystal, the contact ion pair [(TMEDA)Zn(H)(HBPh3)] showed a bent Zn-H-B bridge indicative of a delocalized Zn-H-B interaction. In contrast, a linear Zn-H-B bridge for [(TMPDA)Zn(H)(HBPh3)] was observed, suggesting a contact ion pair. In THF solution, both complexes show an exchange with free BPh3 as well as [HBPh3]-. DFT calculations suggest the presence of [HBPh3]- anion with a highly polarized B-H bond that interacts with the Lewis acidic zinc hydride cation [(L2)Zn(H)]+. The hydridotriphenylborates [(Ln)Zn(H)(HBPh3)] underwent CO2 insertion to give (formato)zinc (formoxy)triphenylborate complexes [(Ln)Zn(OCHO)][(OCHO)BPh3] (Ln = TMPDA, PMDTA, Me4TACD). For Ln = TMEDA, a dinuclear complex [(Ln)2Zn2(μ-OCHO)3][(OCHO)BPh3] was isolated. Hydridotriphenylborates [(Ln)Zn(H)(HBPh3)] catalyzed the hydrosilylation of CO2 (1 bar) by nBuMe2SiH in THF at 70 °C to give formoxysilane and (methoxy)silane.
Reductive elimination of [AlH2]+from a cationic Ga-Al dihydride
Carpentier, Ambre,Maron, Laurent,Morris, Louis J.,Okuda, Jun
supporting information, p. 9454 - 9457 (2021/09/22)
Oxidative addition of TMEDA-supported [AlH2]+to [{BDI}Ga] (BDI = {HC(C(CH3)N(2,6-iPr2-C6H3))2}) provides [{BDI}Ga(H)-Al(H)(tmeda)][B(C6H3-3,5-Me2)4] (TMEDA =N,N,N′N′-tetramethylethylenediamine) with a covalent metal-metal bond. The reaction is readily reversed by substituting TMEDA for an N-heterocyclic carbene or dissolving in THF.
Aluminum nanoparticle preparation: Via catalytic decomposition of alane adducts-influence of reaction parameters on nanoparticle size, morphology and reactivity
Kickelbick, Guido,Klein, Thomas
supporting information, p. 9820 - 9834 (2020/07/30)
Al nanoparticles represent one of the most challenging classes of metal nanoparticles in synthesis and handling due to their high chemical reactivity and their affinity to oxidation. A promising wet chemical preparation route is the catalytic decomposition of alane adducts. In the current systematic study, we investigated the influence of various reaction parameters, such as precursors, catalysts, solvents, reaction temperatures, capping agents, and concentrations of the reactants on the size and morphology of the resulting Al nanoparticles. One major goal was the optimization of the reaction parameters towards short reaction times. Our studies revealed that Ti alkoxides, such as Ti(OiPr)4, are much more efficient decomposition catalysts compared to other related metal catalysts. Optimized conditions for full conversion times smaller than 15 min are temperatures between 90-100 °C and non-polar solvents such as toluene. Amine alanes containing short alkyl chains, for example H3AlNMe2Et or H3AlNEt3, were the most suitable precursors, leading to the formation of the smallest nanoparticles. The use of weakly coordinating capping agents like amines and phosphines should be preferred over the commonly employed carboxylic acids because they do not accelerate the formation of an amorphous oxide shell upon binding to the particle surface. In conclusion, the best reaction parameters for a fast synthesis of Al nanoparticles via a catalytic decomposition approach are the combination of sterically less hindered amine alanes applying a Ti catalyst in toluene solutions in the presence of amine or phosphine stabilizers at elevated temperatures.
Alane complexes of divalent ytterbocenes. Bimetallic mechanism of styrene polymerization
Knjazhanski, Sergei Ya.,Kalyuzhnaya, Elena S.,Elizalde Herrera, Luis E.,Bulychev, Boris M.,Khvostov, Alexei V.,Sizov, Alexandr I.
, p. 19 - 25 (2007/10/03)
Heterometallic complexes of divalent ytterbocenes Cp′2Yb (Cp′ = (tert-Bu)2C5H3, C5Me5) and alanes A1H3 · L (L = NEt3, C4H8O, Et2O) hav
