Al and Zn complexes bearing N,N,N-tridentate quinolinyl anilido-imine ligands: synthesis, characterization and catalysis in L-lactide polymerization.
Reactions of N,N,N-tridentate quinolinyl anilido-imine ligands with AlMe(3) afford mononuclear aluminum complexes {κ(3)-[{2-[ArN=C(H)]C(6)H(4)}N(8-C(9)H(6)N)]}AlMe(2) (Ar = 2,6-Me(2)C(6)H(3) (1a), 2,6-Et(2)C(6)H(3) (1b), 2,6-(i)Pr(2)C(6)H(3) (1c)) or dinuclear complexes AlMe(3){κ(1)-[{2-[ArN=C(H)C(6)H(4)]N(8-C(9)H(6)N)}-κ(2)]AlMe(2) (R = 2,6-Me(2)C(6)H(3) (2a), 2,6-Et(2)C(6)H(3) (2b), 2,6-(i)Pr(2)C(6)H(3) (2c)) depending on the ratios of reactants used. Similar reactions of ZnEt(2) with these ligands give the monoligated ethyl zinc complexes {κ(3)-[{2-[ArN=C(H)]C(6)H(4)}N(8-C(9)H(6)N)]}ZnEt (Ar = 2,6-Me(2)C(6)H(3) (3a), 2,6-Et(2)C(6)H(3) (3b), 2,6-(i)Pr(2)C(6)H(3) (3c)) or bisligated complexes {κ(3)-[{2-[ArN=C(H)]C(6)H(4)}N(8-C(9)H(6)N)]}Zn{κ(2)-[{2-[ArN=C(H)]C(6)H(4)}N(8-C(9)H(6)N)]} (Ar = 2,6-Me(2)C(6)H(3) (4a), 2,6-Et(2)C(6)H(3) (4b), 2,6-(i)Pr(2)C(6)H(3) (4c)). These complexes were well characterized by NMR and the structures of 1a, 2a, 2c, 3b and 4c were confirmed by X-ray diffraction analysis. The aluminum and zinc complexes were tested to initiate lactide polymerization in which the zinc complexes show moderate to high activities in the presence of benzyl alcohol.
State Key Laboratory for Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun 130012, People's Republic of China.
Nan
N
Yang
Lan
L
Xin
Wei
W
Gao
Jingshun
J
Zhang
Xuyang
X
Luo
Xiaoming
X
Liu
Ying
Y
Mu
D000535:Aluminum / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D004146:Dioxanes / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D008024:Ligands; D058105:Polymerization; D011804:Quinolines / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
D000814:Aniline Compounds; D056831:Coordination Complexes; D004146:Dioxanes; D007097:Imines; D008024:Ligands; D011804:Quinolines; C091880:dilactide; D000535:Aluminum; C037219:quinoline; D015032:Zinc; C023650:aniline