Dimeric 1,4‐Dichloro‐2,3,5,6‐tetramethyl‐1,4‐dialumina‐2,5‐cyclohexadiene, a Compound with Aluminum‐Olefin π‐Bonds

Abstract

The low‐temperature reaction of the “high‐temperature” molecule AICI—the first preparative application of an Al subhalide—with CH3CCCH3 gives the title compound 1. The monomers of this air‐ and moisture‐sensitive compound are twisted by 90° with respect to each other. The dimer is held together by four Al‐olefin π bonds. Such compounds were previously unknown.

Lithium–Olefin π-Complexes and the Mechanism of Carbolithiation: Synthesis, Solution Behavior, and Crystal Structure of (2,2-Dimethylpent-4-en-1-yl)lithium

“…The average CC double bond length of 1.322(2) Å in 2 is very close to those of 1.32 Å seen in free olefins, and those of 1.32 to 1.36 Å in olefins bound to calcium, barium, aluminum, and d 0 zirconium centers . In addition, we were able to locate all the olefinic hydrogens in the difference map and to refine their locations without constraints.…”

K[Al4(PPh2)7PPh]: An AlII Phosphanide / Phosphinidene Intermediate on the Path to AlP Formation

“…The Al/P core of complex 1 is closely related to the previously-reported aluminum phosphanide clusters Al 2 (PR 2 ) 4 (2) and Al 4 (PR 2 ) 6 (3) where R = tBu. [9,11] Although the alkyl substituent of the phosphanides differs, the Al/P frameworks in all three compounds have notably similarities in Al-P coordination and metric parameters.…”

“…Low oxidation state aluminum compounds have drawn considerable interest due to their unprecedented structural chemistry, [1] unusual chemical reactivity [2][3][4] and their propensity for metal-metal bond formation. [5][6][7] Solutions of Al I halides have proven to be excellent precursors to low oxidation state Al I complexes, [7] such as Al 4 Cp* 4 , [8] but can also undergo redox (disproportionation) reactions to give new classes of clusters and compounds containing Al oxidation states from 0.27 to 3.0.…”

Synthesis and Characterization of Derivatives of a Chelating Aluminum Dichloride Complex Containing a 3,5-Di-tert-butylpyrazolato Unit

“…The fused five‐membered AlC 2 N 2 ring and the pyrazolato moiety are approximately coplanar. The C=C bond length of the inserted trimethylsilylacetylene molecule is significantly increased [C4−C5 = 1.328(3) Å] but is slightly shorter than the C=C double bonds of the σ complex of AlCl 3 with tetramethylcyclobutadiene [1.387(3) Å]9 and 1,4‐dichloro‐2,3,5,6‐tetramethyl‐1,4‐dialumina‐2,5‐cyclohexadiene [1.367(3) Å] 10. The terminal Al(1)−C bond lengths [1.971(2) Å] are similar to those in [(η 1 ,η 1 ‐3,5‐ t Bu 2 pz)(µ‐AlMe 2 )] 2 [Al−C = 1.962(2) Å] 11…”