Da. Robson et al., An unprecedented coordination mode for hemilabile pendant-arm 1,4,7-triazacyclononanes and the synthesis of cationic organoaluminium complexes, CHEM COMMUN, (14), 2000, pp. 1269-1270
Reaction of AlMe3 or [AlMe3. py] with the pendant arm OH-funtionalised 1,4,
7-triazacyclononane proligands, HL1 or HL2, affords the four- and five-coor
dinate derivatives [Al(L-1)Me-2] 1 or [Al-2(L-2)(2)Me-4] 2 in which the pen
dant alkoxide O-donor and only one macrocycle N-donor is bound to Al; methy
l anion abstraction from 1 yields cationic, pentacoordinate [Al(L-1)Me](+)
in which L-1 has a tetradentate coordination mode [L-1 = 1-(2-hydroxy-3,5-d
i-tert-butylbenzyl)-4,7-diisopropyl-1,4,7-triazcyclononane; L-2 = 1-(2-hy-
droxy-2-methylethyl)-4,7-diisopropyl-1,4,7-triazacyclononane].