Cyclopentanolates of Aluminum Hydride/Aluminum Chloride forming Aluminum‐Oxygen‐Hetero‐Cages and Mixed Coordination Oligomers

Lithium aluminum hydride combined with different amounts of aluminum chloride react with cyclopentanol under the formation of compounds with aluminum‐oxygen scaffolds and hydrogen or chlorine as terminating substituents at aluminum and cyclopentyl at the oxygen atoms. H₆Al₄(OC₅H₉)₆ and Cl₆Al₄(OC₅H₉)₆, both displaying a central aluminum atom almost octahedrally coordinated by oxygen atoms of the cyclopentanolates with three AlH₂ or AlCl₂ entities bridging three oxygen edges were isolated and fully characterized. The compound dihydrido aluminum cyclopentanolate was isolated together with chloro‐hydrido aluminum cyclo‐pentanolate as a 6:2 aggregate, H₂Al(OC₅H₉)]₆H(Cl)Al(OC₅H₉)]₂, displaying alcoholate and hydride bridges in the crystal. Structural isomers of this compound were found in the solid. Mono‐hydrides could be isolated in the form of H₅Al₅(O)(OC₅H₉)₈ * OC₄H₁₀ and in the form of a hydride/chloride H_4.5Cl_0.5Al₅(O)(OC₅H₉)₈ * OC₄H₁₀, which is a 1:1 mixture of H₅Al₅(O)(OC₅H₉)₈ with H₄ClAl₅(O)(OC₅H₉)₈ in the crystal. In both compounds an oxygen atom is in the center of an Al₅ square pyramid. While in the first case the aluminum atom situated at the top of the pyramid has a hydride ligand, in the second case the ligand is a chloride.