摘要
A series of aluminium derivatives containing substituted bidentate and symmetrical tridentate pyrrolyl ligands, [C 4 H 3 NH(2-CH 2 NH t Bu)] and [C 4 H 2 NH(2,5-CH 2 NH t Bu) 2 ], in toluene or diethyl ether were synthesized. Their reactivity and application for the ring opening polymerization of ε-caprolactone have been investigated. The reaction of AlMe 3 with one equiv. of [C 4 H 3 NH(2-CH 2 NH t Bu)] in toluene at room temperature affords [C 4 H 3 N(2-CH 2 NH t Bu)]AlMe 2 (1) in 70% yield by elimination of one equiv. of methane. Interestingly, while reacting AlMe 3 with one equiv. of [C 4 H 3 NH(2- CH 2 NH t Bu)] in toluene at 0°C followed by refluxing at 100°C, [{C 4 H 3 N(2-CH 2 N t Bu)}AlMe] 2 (2) has been isolated via fractional recrystalliztion in 30% yield. Similarly, reacting AlMe 3 with two equiv. of C 4 H 3 NH(2-CH 2 NH t Bu) generates [C 4 H 3 N(2-CH 2 NH t Bu)] 2 AlMe (3) in a moderate yield. Furthermore, complex 1 can be transformed to an aluminium alkoxide derivative, [C 4 H 3 N(2-CH 2 NH t Bu)][OC 6 H 2 (-2,6- t Bu 2 -4-Me)]AlMe (4) by reacting 1 with one equiv. of HOC 6 H 2 (-2,6- t Bu 2 -4-Me) in toluene via the elimination of one equiv. of methane. The reaction of AlR 3 with one equiv. of [C 4 H 2 NH(2,5-CH 2 NH t Bu) 2 ] in toluene at room temperature affords [C 4 H 2 N(2,5-CH 2 NH t Bu) 2 ]AlR 2 (5, R = Me; 6, R = Et) in moderate yield. Surprisingly, from the reaction of two equiv. of [C 4 H 2 NH(2,5-CH 2 NH t Bu) 2 ] with LiAlH 4 in diethyl ether at 0°C, a novel complex, [C 4 H 2 N(2-CH 2 N t Bu)(5-CH 2 NH t Bu)] 2 AlLi (7) has been isolated after repeating re-crystallization. Furthermore, reacting one equiv. of C 4 H 2 NH(2,5-CH 2 NH t Bu) 2 with AlH 3 ·NMe 3 in diethyl ether generates an aluminium dihydride complex, [C 4 H 2 N(2,5-CH 2 NH t Bu) 2 ]AlH 2 (8), in high yield. Additionally, treating 8 with one equiv. of HOC 6 H 2 (-2,6- t Bu 2 -4-Me) in methylene chloride produces [C 4 H 2 N(2,5-CH 2 NH t Bu) 2 ][OC 6 H 2 (-2,6- t Bu 2 -4-Me)]AlH (9) with the elimination of one equiv. of H 2 . The aluminium alkoxide complex 4 shows moderate reactivity toward the ring opening polymerization of ε-caprolatone in toluene. © 2011 The Royal Society of Chemistry.