Preparation of Heterobimetallic Oxide–Hydroxide–Hydrogensulfides [LAl(OH)(μ‐O)MCp₂(SH)] (M=Ti, Zr)

Abstract

Dedicated to Professor Thomas B. RauchfussRecently we reported the preparation of heterobimetallic sulfides that contained aluminum atoms [LAl(m-S) 2 MCp 2 ] (M = Ti, 1; M = Zr, 2; L = HC[C(Me)N(2,6-iPr 2 C 6 H 3 )] 2 ; Cp = C 5 H 5 ).[1] The X-ray crystal structural analysis of the titanium compound 1 confirmed the presence of a highly strained {Al(m-S) 2 Ti} four-membered ring (S-Al-S 102.5(1), Al-S-Ti 84.7(1) and 83.6(1), S-Ti-S 89.3(1)8). The ring strain and the short Al···Ti separation (3.118 ) prompted us to examine the reactivity of 1 and 2 with water in expectation of a nucleophilic attack that would lead to the opening of the ring and to the isolation of compounds containing the {LAl(EH)(m-E)M(EH)Cp 2 } framework (E = O or S depending on the degree of hydrolysis). Such species could serve as unique precursors for the preparation of trimetallic systems comparable with the alumoxane [(m-O) Although a few dinuclear systems that contain the {M'(EH)-(m-E)M(EH)} arrangement have been described (M' = Al, [2] Fe, [3a] Ge, [3b,c] ) none has been structurally characterized that contains two different metal atoms stabilized by organic ligands.The addition of two equivalents of water to a solution of 1 or 2 in THF at room temperature led, after overnight stirring, to the precipitation of a crystalline material. H 2 S was identified as a by-product. The solid product was filtered off, dried in vacuo, and isolated as pale brown (Ti) or pale yellow (Zr) microcrystals. The 1 H NMR spectroscopic, EI mass spectrometric, and X-ray crystal structural analysis of these products confirmed that the ring-opening reaction had occurred, but revealed the presence of two derivatives in the samples The driving force for this intramolecular rearrangement is the high oxophilicity of the metal centers and the higher stability of the {Al-O-Ti} frame compared to {Al-S-Ti}.

Studies of the Ligand Effect on the Synthesis of Dialuminoxanes by Various β-Diketiminato Ligands

“…This should be due to the less steric demanding ligand that could not sufficiently prevent the intermolecular reactions between reactants of AlI/AlH and active Al(OH) species in a nonstoichiometric ratio. These results are in sharp contrast to the facile preparation of i Pr LAl(OH) 2 by hydrolyzing i Pr LAlI 2 , i Pr LAlCl 2 , i Pr LAlCl(I), and i Pr LAl(SH) 2 , respectively. , …”

Solubilizing functionalized molecular aluminosilicates

“…It is known that the compound LAl(OH) 2 is labile and decomposes easily, but the presence of an Al-(m-O)-M (M = metal) bridge can stabilize the terminal OH group attached to the aluminum atom. 8 In compound 3, such an hydroxy group is coordinated to a THF molecule, while acting Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, México, D. F. Mexico. E-mail: vjancik@servidor.unam.mx, cea@servidor.unam.mx; Fax: +52 555 as an acceptor for the proton from the OH group on the silicon atom.…”

Reaction of sterically encumbered phenols, TEMPO-H, and organocarbonyl insertion reactions with L-AlH2 (L = HC(MeCNDipp)2, Dipp = 2,6-diisopropylphenyl)

“…This is in line with other bdiketiminate-based terminal aluminum monohydroxides in the literature. [33][34][35][36][37][38][39][40][41][42]…”