False impressions from aluminum-27 NMR spectroscopy

Dimeric alumatranes as catalysts for trimethylsilylcyanation reaction

First structurally characterized dimeric alumatranes with tricyclic five-membered rings were determined by single-crystal X-ray analysis and DFT calculations. New alumatranes were used as catalysts for trimethylsilycyanation reaction of aldehydes.

Organoaluminium complexes incorporating an amido phosphine chelate with a pendant amine arm

The palladium-catalyzed aryl amination of 1-bromo-2-fluorobenzene with N,N-dimethylethylenediamine quantitatively produces N-(dimethylaminoethyl)-2-fluoroaniline, which subsequently reacts with KPPh2 in 1,4-dioxane to afford N-(dimethylaminoethyl)-2-diphenylphosphinoaniline (H[PNN]). The reactions of trialkylaluminium with H[PNN] in toluene generate the corresponding aluminium dialkyl complexes [PNN]AlR2 (R = Me, Et, i-Bu). The solution NMR spectroscopic and X-ray crystallographic studies are indicative of a trigonal bipyramidal geometry for these aluminium complexes in which the amino nitrogen atom is trans to the phosphorus donor of the [PNN]- ligand. This study presents rare examples of structurally characterized, five-coordinate aluminium hydrocarbyl complexes supported by phosphine-derived ligands.

The first example of a monomeric alumatrane

The novel five-coordinate aluminum adduct Me(2)HN. AlL (2) [wherein L = tris(2-oxy-3,5-dimethylbenzyl)amine] containing three six-membered rings has been characterized by spectroscopic and by X-ray means. This adduct of an alumatrane is the first structurally characterized monomeric alumatrane derivative, and unlike its parent alumatrane [Al(OCH(2)CH(2))(3)N](x), 2 is monomeric in the gas, solution, and solid states. The X-ray molecular structure of 2 reveals a tricyclic cage moiety of C(3) symmetry. The aluminum geometry is a slightly distorted trigonal bipyramid in which, quite unexpectedly, the metal atom is located somewhat below the plane formed by three equatorial oxygens and its Al-N(tertiary) bond is shorter than that in Me(3)N.AlH(3).NMe(3) (Heitsch, C. W.; Nordman, C. E.; Parry, R. W. Inorg. Chem. 1963, 2, 508).