Cationic aluminium hydrides: [H2AlL]+[AlH4]–, L =N,N,N′,N″,N″-pentamethyldiethylenetriamine and 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane
Abstract
Reaction of H3AlNMe3 with N,N,N′,N″,N″-pentamethyldiethylenetriamine (pmdien) in diethyl ether or 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane (Me4cyclam) in tetrahydrofuran yields [H2Al(pmdien)]+[AlH4]–, which possesses a trigonal bipyramidal cation with the hydrides in the trigonal plane [Al–N′ 2.158(7), Al–N,N″ 2.01(1), Al–H 1.62 Å] or [H2Al(Me4 cyclam)]+[AlH4], where the metal centre in the cation is trans-octahedral [Al–N(mean) 2.13, Al–H 1.60, 1.64 Å].