Tetranuclear Ga(III) complexes L^1–3₂Ga₄(t-Bu)₈ 1–3 are synthesized and characterized (elemental analysis, IR, ¹H, ¹³C, DOSY NMR spectroscopy, XRD) and their activity in the ring-opening polymerization (ROP) of lactide (LA) and ϵ-caprolactone (ϵ-CL) is reported. Complex 1 is the most active homopolymerization catalyst in the presence of benzyl alcohol (BnOH), yielding isotactic-enriched polylactides (PLAs) with P_m (probably of mesomerism) values up to 0.72 by a first order kinetic with respect to the monomer concentration. The living character of the polymerization process was confirmed by a polymerization resumption experiment. Complexes 1–3 are also active catalysts in the copolymerization of LA and ϵ-CL, and sequential addition of both monomers gave well-defined block copolymers with narrow Đ values (distributions of molecular weight).

中文翻译：

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镓席夫碱配合物在环状酯开环均聚和共聚反应中的合成及催化活性

四核 Ga(III) 配合物 L ^1–3 ₂ Ga ₄ ( t -Bu) ₈ 1 – 3被合成和表征（元素分析、IR、¹ H、¹³ C、DOSY NMR 光谱、XRD）及其在环中的活性报道了丙交酯（LA）和ε-己内酯（ε -CL）的开环聚合（ROP）。在苯甲醇 (BnOH) 存在下，配合物1是活性最高的均聚催化剂，可生成具有P _{m 的全}同立构富聚聚乳酸 (PLA)（可能是异构现象）通过关于单体浓度的一级动力学值高达 0.72。聚合过程的活性特征通过聚合恢复实验得到证实。配合物1 - 3也是 LA 和ϵ -CL共聚的活性催化剂，两种单体的顺序添加得到了定义明确的具有窄Đ值（分子量分布）的嵌段共聚物。