The molecular structure of enigmatic "poly(aluminium-methyl-methylene)" (first reported in 1968) has been unraveled in a transmetalation reaction with gallium methylene [Ga (CH ) ] and AlMe . The existence of cage-like methylaluminomethylene moieties was initially suggested by the reaction of rare-earth-metallocene complex [Cp* Lu{(μ-Me) AlMe }] with excess AlMe affording the deca-aluminium cluster [Cp* Lu (μ -CH ) Al (CH ) ] in low yield (Cp*=C Me ). Treatment of [Ga (CH ) ] with excess AlMe reproducibly gave the crystalline dodeca-aluminium complex [(CH ) Al (μ -CH ) ] (MAM-12). Revisiting a previous approach to "poly(aluminium-methyl-methylene" by using a (C H ) TiCl /AlMe (1 : 100) mixture led to amorphous solids displaying solubility behavior and spectroscopic features similar to those of crystalline MAM-12. The gallium methylene-derived MAM-12 was used as an efficient methylene transfer reagent for ketones.
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http://dx.doi.org/10.1002/chem.202200823 | DOI Listing |
Chem Commun (Camb)
January 2025
Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany.
The homoleptic complex La(InMe) is obtained from the respective aluminium congener La(AlMe) a donor-assisted tetramethylaluminate/tetramethylindate exchange protocol. Compound La(InMe) exhibits interesting thermal lability as well as distinct cluster formation like LaIn(C)(CH)(CH)(CH) and LaIn(CH)(CH) upon addition of an excess of donor or thermal treatment. The neutral potentially tridentate ligand MeTACN (1,4,7-trimethyl-1,4,7-triazacyclononane) is used to investigate donor-triggered intermediates.
View Article and Find Full Text PDFInorg Chem
April 2024
School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, P. R. China.
To systematically investigate the dependence of the initiating group and metal size on polymerization performance, a family of rare-earth metal bis(alkyl)/bis(benzyl)/bis(amide) complexes supported by a monoanionic tridentate amidinate ligand [(2,6-PrCH)NC(Ph)N(CH-2-OMe] () were synthesized and well-characterized. Treatment of rare-earth metal tris(alkyl)/tris(benzyl)/tris(amide) complexes Y(CHCHNMe-) or Y(CHSiMe)(THF) or Ln[N(SiHMe)](THF) (Ln = Sc, x = 1; Ln = Y, La, Sm, Lu, x = 2) with 1 equiv of gave the corresponding mono(amidinate) rare-earth metal bis(alkyl)/bis(benzyl)/bis(amide) complexes [(2,6-PrCH)NC(Ph)N(CH-2-OMe)]Y(CHCHNMe-) (), [(2,6-PrCH)NC(Ph)N(CH-2-OMe)]Y(CHSiMe)(THF) (), and [(2,6-PrCH)NC(Ph)N(CH-2-OMe)]Ln[N(SiHMe)](THF) (Ln = Y, = 1 (); Ln = La, = 1 (); Ln = Sc, = 0 (); Ln = Lu, = 0 (); Ln = Sm, = 0 ()) in good isolated yields. These complexes were characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction.
View Article and Find Full Text PDFChemphyschem
February 2023
Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, F80100, Joensuu, Finland.
The interactions of the Lewis bases CO, octamethyltrisiloxane (OMTS) and 2,2'-bipyridine (bipy) with a sheet model for the principal activator (MeAlO) (Me Al) (16,6) in hydrolytic methylaluminoxane (MAO) were investigated by DFT. These studies reveal that OMTS and bipy form adducts with Me Al prior to methide abstraction by 16,6 to form the ion-pairs [Me Al(κ -L)][16,6] (5: L=OMTS, 6: L=bipy, [16,6] =[(MeAlO) (Me Al) Me] ) while CO simply binds to a reactive edge site without ionization. The binding and activation of Cp ZrMe with 16,6 to form both neutral adducts 1 Cp ZrMe ⋅16,6 and contact ion-pairs 4 and 7, both with formula [Cp ZrMe][μ-Me(MeAlO) (Me Al) ], featuring terminal and chelated MAO-anions, respectively was studied by DFT.
View Article and Find Full Text PDFChemistry
August 2022
Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
The molecular structure of enigmatic "poly(aluminium-methyl-methylene)" (first reported in 1968) has been unraveled in a transmetalation reaction with gallium methylene [Ga (CH ) ] and AlMe . The existence of cage-like methylaluminomethylene moieties was initially suggested by the reaction of rare-earth-metallocene complex [Cp* Lu{(μ-Me) AlMe }] with excess AlMe affording the deca-aluminium cluster [Cp* Lu (μ -CH ) Al (CH ) ] in low yield (Cp*=C Me ). Treatment of [Ga (CH ) ] with excess AlMe reproducibly gave the crystalline dodeca-aluminium complex [(CH ) Al (μ -CH ) ] (MAM-12).
View Article and Find Full Text PDFMolecules
December 2021
Department of Chemistry, National Changhua University of Education, Changhua 500, Taiwan.
A series of chelated dehydroacetic acid-imine-based ligands ~ was synthesized by reacting dehydroacetic acid with 2-t-butylaniline, ()-1-phenyl-ethylamine, 4-methoxylbenzylamine, and 2-(aminoethyl)pyridine, respectively, in moderate yields. Ligands ~ reacted with AlMe in toluene to afford corresponding compounds (), (), (), and (). All the ligands and aluminum compounds were characterized by IR spectra, H and C NMR spectroscopy.
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