Electron-Deficient β‑Diiminato-Zinc-Ethyl Complexes: Synthesis, Structure, and Reactivity in Ring-Opening Polymerization of Lactones
datasetposted on 17.02.2016, 00:00 by Alexander Kronast, Marina Reiter, Peter T. Altenbuchner, Christian Jandl, Alexander Pöthig, Bernhard Rieger
A series of β-diiminato zinc(II) complexes bearing two electron-withdrawing trifluoromethyl groups in the pentane ligand backbone were successfully isolated ((BDICF3-I)H = [CH(CCF3NC6H4-2,6-CH(CH3)2)2]; (BDICF3-II)H = [CH(CCF3NC6H4-2,6-C2H5)2], and (BDICF3-III)H = [CH(CCF3NC6H4-2,6-CH3)2]). The solid-state structures illustrate differences in the ligation of the Zn atom compared to a literature known BDI-ZnEt complex. All catalysts show good activities in the ring-opening polymerization of the cyclic ester (rac)-β-butyrolactone (BL), whereas only BDICF3-II-ZnEt and BDICF3-III-ZnEt are active initiators for the polymerization of (rac)-lactide (LA).