Novel chromium complexes with a [OSSO]-type bis(phenolato) dianionic ligand mediate the alternating ring-opening copolymerization of epoxides and phthalic anhydrideElectronic supplementary information (ESI) available. See DOI: 10.1039/c5py01040c

• Main Authors: Si, Gaoshan, Zhang, Li, Han, Bing, Duan, Zhongyu, Li, Boqian, Dong, Jincheng, Li, Xiangqing, Liu, Binyuan
• Format: Journal Article
• Language: English
• Published: 25.08.2015
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/c5py01040c

Four new homogeneous chromium complexes with [OSSO]-type bis(phenolato) dianionic ligand catalysts for the ring-opening copolymerization of phthalic anhydride (PA) and epoxides are reported. Through the structure design, the ligand with a cyclohexylene ring backbone of the chromium complexes is quite beneficial to improving the activity. Of all the cocatalysts employed, DMAP is found to be the most efficient. 1 H NMR spectra of the copolymers confirmed the alternating microstructures. This is the first example of a well-defined metal complex with a soft Lewis base as donor for the efficient copolymerization of anhydride and epoxides. Additionally, we demonstrate that poly(4-VCHO- alt -PA) can be conveniently functionalized using a robust free-radical mediated thiol-ene reaction of the pendant vinyl groups. Polyesters are efficiently prepared from ROCOP of PA and epoxides with [OSSO]CrX/Lewis base binary catalyst. The VCHO-derivatized polyesters can be functionalized by a thiol-ene reaction.