Lithium Quinolyl‐Amidinates Efficiently Promoting Ring‐Opening Polymerization of ε‐Caprolactone: Synthesis and ⁷Li NMR Spectroscopic Studies

Abstract

Lithium complexes (Li1-Li5) of tridentate quinolylamidinate scaffolds were successfully synthesized in high yields and characterized by 1 H NMR spectroscopy and multinuclear solution 7 Li NMR spectroscopy. The molecular structures of representative complexes Li2 and Li3 were established by singlecrystal X-ray diffraction analysis, indicating two four-coordinate lithium atoms connected through two amidinate units. Interestingly, one Li atom is coordinated exclusively by the four N [a]

Highly active tridentate amino-phenol zinc complexes for the catalytic ring-opening polymerization of ε-caprolactone

“…As shown in Fig. 1, the coordination geometry around the zinc center is distorted tetrahedral, with bond angles in the range of 93.14(9) e 114.47 (8) . The structure is similar to that of the corresponding cobalt and nickel complexes [68e70].…”

Construction of Alkali‐metal‐based Imidazolecarboxylate Coordination Polymers as Efficient Catalysts for Solvent‐free Ring‐opening polymerization of ϵ‐Caprolactone

“…[14] Discrete complexes with alkali-metal ions have become a particularly attractive class of ROP catalysts over the past decade owing to their low cost and non-toxicity as well as high stereoselectivity control. [15][16][17][18][19][20] These catalysts are ion-pair complexes and the ROP process proceeds via a anionic mechanism. Of particular note are the lithium(I)-based complexes with various ligands reported by Lin [6] and Otero et al, [21,22] which were used for catalytic CL polymerization.…”