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A series of low-cost Lewis acidic deep eutectic solvents (DESs) was synthesized and applied for the first time for catalyzing the polymerization of α-pinene to produce terpene resins. The DES catalyst of [AlCl3]3[CPL] prepared via the self-assembly of AlCl3 and caprolactam (CPL) exhibited the highest catalytic activity, and polymerization conditions were optimized by a single-factor method: 15 g α-pinene, 3 g catalyst, 1 g initiator, −5 °C reaction temperature, and 4 h reaction time. Under these conditions, the softening point of the terpene resin reached (annular spheroid method) 118.3 °C, the acid value was 0.22 mg KOH g−1, and the depth of color (Fe–Co method) was 5. The structure of [AlCl3]3[CPL] was characterized using FT-IR, 1H-NMR, and UV-vis spectroscopy. GPC measure showed that the number-average molecular weight of the terpene resin was 510, the weight-average molecular weight was 776, and the polydispersity index was 1.523. TG results indicated that the terpene resin had favorable thermal stability. After the reaction, the product and the catalyst could be automatically divided into two phases, which was beneficial for recycling the catalyst. The results revealed that [AlCl3]3[CPL] exhibited good recyclability. [ABSTRACT FROM AUTHOR]

Coinage metal-alkynyl clusters have been developed rapidly over the past few decades. An attractive area of this field is the integration of polyoxometalates (POMs) to direct the formation of metal-alkynyl clusters. POMs are metal-oxide clusters with unique structural diversity and tunable properties, and by incorporation of POM anions into the skeleton, the resulting clusters could be stabilized, functionalized, and so on. Herein, we summarize the advances in POM-based homo and heterometallic copper/silver-alkynyl clusters. [ABSTRACT FROM AUTHOR]