TY - JOUR
T1 - (Benz)Imidazolin-2-iminato Aluminum, Zinc, and Magnesium Complexes and Their Applications in Ring Opening Polymerization of ϵ-Caprolactone
AU - Liu, Heng
AU - Khononov, Maxim
AU - Fridman, Natalia
AU - Tamm, Matthias
AU - Eisen, Moris S.
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/10/7
Y1 - 2019/10/7
N2 - Synthesis and characterization of a new family of aluminum, magnesium, and zinc complexes supported by (benz)imidazolin-2-iminato ligands are reported herein. Under different reaction conditions, (benz)imidazolin-2-imine ligands reacted with metal alkyl precursors to afford the corresponding complexes, displaying mononuclear, binuclear, and trinuclear structures. Reaction in 1:1 stoichiometry at room temperature afforded the simple Lewis acid-base adducts, which exhibited distorted tetrahedral geometries around the metal centers, whereas high temperature reactions gave rise to dimeric complexes, with each metal bridging two (benz)imidazolin-2-imine ligands to form a four-membered metallacycle ring at the center of the complexes. The catalytic ring opening polymerization (ROP) of ϵ-caprolactone was studied using these complexes as precatalysts in the presence of isopropanol, and very high activities were observed, affording high/medium molecular weight poly(ϵ-caprolactone) products with low polydispersity indices. Detailed kinetic studies revealed that the polymerizations proceeded in a living manner and molecular weights of the polymers could be precisely controlled.
AB - Synthesis and characterization of a new family of aluminum, magnesium, and zinc complexes supported by (benz)imidazolin-2-iminato ligands are reported herein. Under different reaction conditions, (benz)imidazolin-2-imine ligands reacted with metal alkyl precursors to afford the corresponding complexes, displaying mononuclear, binuclear, and trinuclear structures. Reaction in 1:1 stoichiometry at room temperature afforded the simple Lewis acid-base adducts, which exhibited distorted tetrahedral geometries around the metal centers, whereas high temperature reactions gave rise to dimeric complexes, with each metal bridging two (benz)imidazolin-2-imine ligands to form a four-membered metallacycle ring at the center of the complexes. The catalytic ring opening polymerization (ROP) of ϵ-caprolactone was studied using these complexes as precatalysts in the presence of isopropanol, and very high activities were observed, affording high/medium molecular weight poly(ϵ-caprolactone) products with low polydispersity indices. Detailed kinetic studies revealed that the polymerizations proceeded in a living manner and molecular weights of the polymers could be precisely controlled.
UR - http://www.scopus.com/inward/record.url?scp=85072927925&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.9b02324
DO - 10.1021/acs.inorgchem.9b02324
M3 - 文章
C2 - 31556598
AN - SCOPUS:85072927925
SN - 0020-1669
VL - 58
SP - 13426
EP - 13439
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 19
ER -