Cubane‐Type Polynuclear Zinc Complexes Containing Tridentate Schiff Base Ligands: Synthesis, Characterization, and Ring‐Opening Polymerization Studies of rac‐Lactide and ε‐Caprolactone. Issue 11 (14th November 2017)

• Record Type: Journal Article
• Authors: Ghosh, Swarup; Spannenberg, Anke; Mejía, Esteban
• Is Part Of: Helvetica chimica acta. Volume 100:Issue 11(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-11-14
• Subjects: Zinc -- Cage compounds -- Schiff bases -- Ring‐opening polymerization -- Polymers; Chemistry -- Periodicals; Chemistry, Analytical -- periodicals; Chimie -- Périodiques; 540
• DOI: 10.1002/hlca.201700176
• Languages: English
• ISSNs: 0018-019X

Abstract

Abstract : New polynuclear zinc complexes containing tridentate Schiff base ligands were successfully synthesized and fully characterized. The solid‐state structure of the complexes was determined using single crystal X‐ray diffraction. The complexes display a tetranuclear cubane‐like core structure [Zn4 O4 ] and sowed good catalytic activity towards the ring‐opening polymerization (ROP) of rac ‐lactide ( rac ‐LA) and ε ‐caprolactone ( ε ‐CL) under solvent‐free conditions. The polylactic acid (PLA) obtained from rac ‐LA showed isotactic enrichment, as proved by homonuclear decoupled 1 H‐NMR analysis. These complexes also showed good activity and superior control towards the ROP of rac ‐LA and ε ‐CL in the presence of benzyl alcohol as a co‐initiator. Furthermore, kinetic studies demonstrated that the ROP of rac ‐LA and ε ‐CL has a first order dependence on both monomer ( rac ‐LA and ε ‐CL) and catalyst concentration. Abstract :