The influences of the concentration and generation of polyamidoamine dendrimer, the ratio of dodecanoic acid to toluene, and pH in the water phase on the extraction yield of helianthine were systematically studied by ...The influences of the concentration and generation of polyamidoamine dendrimer, the ratio of dodecanoic acid to toluene, and pH in the water phase on the extraction yield of helianthine were systematically studied by selecting helianthine as the guest molecule and electrostatic self-assembled PAMAM as the host. The experimental results show that the extraction yield of helianthine increased with the increase of the generation and concentration of the polyamidoamine dendrimer. When the mass ratio of dodecanoic acid to toluene was 1∶10, pH value was 7.3, the extraction yield of helianthine was the maximum. When the concentrations of 1.0, 2.0 and 3.0 generations of polyamidoamine dendrimer were all 0.21 mmol/L, their self-assembled dendrimers of 1.0, 2.0 and 3.0 generations of polyamidoamine dendrimer with dodecanoic acid exhibited the corresponding maximal extraction yields of helianthine, i.e., 6.04%, 41.61% and 68.50%, respectively. The action mechanism of the host-guest molecule in the phase transfer system is analyzed.展开更多
制备了聚酰胺-胺(PAMAM)-2-吡啶甲醛(Py)席夫碱树枝状大分子及其钯配合物。通过红外、核磁共振、元素分析、等离子耦合原子发散光谱及热重-差热等分析手段对其进行了结构确证。研究了PAMAM-2-吡啶甲醛席夫碱钯配合物在Heck反应中的催化...制备了聚酰胺-胺(PAMAM)-2-吡啶甲醛(Py)席夫碱树枝状大分子及其钯配合物。通过红外、核磁共振、元素分析、等离子耦合原子发散光谱及热重-差热等分析手段对其进行了结构确证。研究了PAMAM-2-吡啶甲醛席夫碱钯配合物在Heck反应中的催化性能。以三乙胺(Et_3N)作为缚酸剂,碘代苯(Ph I):10 mmol,n(Ph I)∶n(AA)∶n(Et_3N)为1∶1.4∶2.5,n(Pd)=6.1×10-3mmol(5.0G PAMAMPy-Pd),在5 m L DMF中,100℃和N_2气保护下反应25 min,产率90.1%。催化剂经过简单的过滤可回收,重复使用3次产率仍可达82.0%。展开更多
文摘The influences of the concentration and generation of polyamidoamine dendrimer, the ratio of dodecanoic acid to toluene, and pH in the water phase on the extraction yield of helianthine were systematically studied by selecting helianthine as the guest molecule and electrostatic self-assembled PAMAM as the host. The experimental results show that the extraction yield of helianthine increased with the increase of the generation and concentration of the polyamidoamine dendrimer. When the mass ratio of dodecanoic acid to toluene was 1∶10, pH value was 7.3, the extraction yield of helianthine was the maximum. When the concentrations of 1.0, 2.0 and 3.0 generations of polyamidoamine dendrimer were all 0.21 mmol/L, their self-assembled dendrimers of 1.0, 2.0 and 3.0 generations of polyamidoamine dendrimer with dodecanoic acid exhibited the corresponding maximal extraction yields of helianthine, i.e., 6.04%, 41.61% and 68.50%, respectively. The action mechanism of the host-guest molecule in the phase transfer system is analyzed.
文摘制备了聚酰胺-胺(PAMAM)-2-吡啶甲醛(Py)席夫碱树枝状大分子及其钯配合物。通过红外、核磁共振、元素分析、等离子耦合原子发散光谱及热重-差热等分析手段对其进行了结构确证。研究了PAMAM-2-吡啶甲醛席夫碱钯配合物在Heck反应中的催化性能。以三乙胺(Et_3N)作为缚酸剂,碘代苯(Ph I):10 mmol,n(Ph I)∶n(AA)∶n(Et_3N)为1∶1.4∶2.5,n(Pd)=6.1×10-3mmol(5.0G PAMAMPy-Pd),在5 m L DMF中,100℃和N_2气保护下反应25 min,产率90.1%。催化剂经过简单的过滤可回收,重复使用3次产率仍可达82.0%。
