Synthesis of a base-stabilized alumoxane: preferential hydrolysis of an aluminium–amido over an aluminium–alkyl

Aluminum Dihydroxide with Terminal OH Groups: An Unprecedented Congener of Boronic Acid

“…[14] However, The AlÀOH bond lengths of 2 are comparable to those of the AlÀ(m-O) bonds in [(HC{(CMe)(NMe)} 2 AlCl) 2 (m-O)] (1.6770(6) ) [15] and [{(tBu) 2 Al(NH(Me)CH 2 CH 2 NMe 2 )} 2 (m-O)] (1.690(7) and 1.714(7) ), [16] in which the linear or almost linear {Al 2 (m-O)} cores lead to the significant double-bond (16) and 1.8617(16) ), [15] and similar to those in [LAl(SeH) 2 ] (1.8996(6) ). [17] Ab initio [18] calculations were carried out to investigate the intermolecular hydrogen bonding and the electronic structure of 2.…”

Preparation of Molecular Alumoxane Hydrides, Hydroxides, and Hydrogensulfides

“…The remaining two coordination sites are occupied by sulfur and oxygen atoms ( 3 ), two oxygen atoms ( 4 ), or two sulfur atoms ( 5 ). The Al‐O‐Al angle in 3 (155.2°), is more obtuse than that in 4 (136.8°) and those found in [{ i Pr LAl(OH)} 2 (μ‐O)] (112.3°) and [(μ‐O){ i Pr LAl(μ‐O)} 2 (AlMe)] (125.7°),5a but significantly smaller than those reported for [{( t Bu) 2 Al(3,5‐Me 2 py)} 2 (μ‐O)] (180°; 3,5‐Me 2 py=3,5‐dimethylpyridine)5b and for [{( t Bu) 2 Al[NH(Me)CH 2 CH 2 NMe 2 ]} 2 (μ‐O)](180°) 5c. The Al(μ‐O) distances in 3 (1.687 Å) are only slightly longer than those in 4 (1.691, 1.701 Å), which are comparable to those in [{ i Pr LAl(OH)} 2 (μ‐O)] (1.698, 1.694 Å), but shorter than that reported for [(μ‐O){ i Pr LAl(μ‐O)} 2 (AlMe)] (av 1.715 Å) 5a.…”

Synthesis, Structural Characterization, and Reaction of the First Terminal Hydroxide‐Containing Alumoxane with an [{Al(OH)}2(μ‐O)] Core

“…The OH groups are bent out of the Al(1)O(3)Al(2) plane (31.26° and 30.71°) towards the opposite side where the 2,6‐ i Pr 2 C 6 H 3 substituents are oriented. The Al‐(μ‐O) bond lengths (1.698(3) and 1.694(3) Å) are comparable, and the Al‐(μ‐O)‐Al angle (143.84(16)°) is significantly smaller than those found in compounds [{[(Me 3 Si) 2 HC] 2 Al} 2 (μ‐O)] (1.6877(4) Å; 180°),11 [{( t Bu) 2 Al[NH(Me)CH 2 CH 2 NMe 2 ]} 2 ](μ‐O) (1.690(7) Å; 173.0(4)°),12 and [{HC[(CMe)(NMe)] 2 AlCl} 2 (μ‐O)] (1.6770(6) Å; 180°) 13. The AlOH bond lengths (1.738(3) and 1.741(3) Å) of 3 are significantly longer than those in 1 (1.6947(15) and 1.7107(16) Å),8 but considerably shorter than those of the Al(μ‐OH) and Al(μ 3 ‐OH) bonds exhibited by compounds [(Ph 2 Si) 2 O 3 ] 4 Al 4 (μ‐OH) 4 (1.787(3) to 1.814(3) Å, average 1.800 Å),14 [{Mes 2 Al(μ‐OH)} 2 ]⋅2 THF (1.822 Å; Mes=mesityl),3e and [Al 5 ( t Bu) 5 (μ 3 ‐O) 2 (μ 3 ‐OH) 2 (μ‐OH) 2 (μ‐O 2 CPh) 2 ] (Al(μ 3 ‐OH), 1.914(5) to 2.086(4) Å; Al(μ‐OH), 1.820(3) to 1.828(3) Å) 15.…”