A series of gold nanoparticles (AuNPs) was prepared in situ with different cucurbit[n]urils (CB[n]s) in an alkaline aqueous solution. The nanoparticle sizes can be well controlled by CB[n]s (n=5,6,7,8) with different ring sizes. The packing densities of CB[5–8] and free surface area on AuNPs were determined. A direct relationship was found between the ring size and packing density of CB[n]s with respect to the AuNP-catalyzed reduction of 4-nitrophenol in the presence of NaBH4. The larger particle size and higher surface coverage of bigger CB[n]-capped AuNPs significantly decreased the catalytic activity. Furthermore, this work could lead to new applications that utilize AuNPs under an overlayer of CB[n]s for catalysis, sensing, and drug delivery.Keywords:gold nanoparticles;cucurbit[n]urils;controllable synthesis;catalysis
Bo Xiao,Ying Fan,Ning-Ning Ji,Xiao-Jie Cheng,Chuan-Zeng Wang,Jia-Jia Zhou,Sai-Feng Xue,Zhu Tao,Qian-Jiang Zhu
Using the one-pot, direct strategy reported by Su and co-workers, we have synthesised a series of cucurbit[n]urils (Q[n], n = 5–8) and alkyl-substituted cucurbit[6]urils (SQ[6]s) anchored on polymers. Acrylamide, as a typical monomer, was used to synthesise a series of Q[n]s (n = 5–8) and SQ[6]-anchored polyacrylamides (PAMs) using a persulfate salt as initiator and oxidant. The Q[n]s (n = 5–8) and SQ[6]-anchored PAM samples have been characterised by 1H NMR, 1H NMR titrations of probe guests, Fourier-transform infrared and thermogravimetric analyser. The results confirmed that PAM chains had been successfully grafted on the back of the Q[n]s (n = 5–8) and SQ[6]s through an in situ radical polymerisation approach. It was further confirmed that the hydrophobic cavities of the Q[n]s on the polymers were still freely accessible. This synthetic approach may be extended to a variety of Q[n]s that are difficult to functionalise.
Fan Ying,Gao Ruihan,Jiang Yangming,Bian Bing,Tao Zhu,Wei Gang,Xiao Xin
In this work, we report a conceptual strategy for preventing pesticide degradation using cucurbit[n]uril to encapsulate pyroquilon (Pyn). The host–guest inclusion complexes of pyroquilon (Pyn) with CB[7] and CB[8] were prepared and characterized using 1 H NMR spectroscopy, quadrupole-time of flight mass spectrometry (Q-TOF), isothermal titration calorimetry (ITC) and UV absorbance spectrophotometry. The experimental results revealed that the entire Pyn molecule resides within the cavities of CB[7] and CB[8], forming 1:1 inclusion complexes between CB[n] and Pyn. Our study on the release of Pyn demonstrated that CB[n]@Pyn exhibit sustained- and slow-release properties. Moreover, CB[8] can effectively shield UV irradiation and thereby protect the Pyn from photodegradation. Therefore, CB[7]@Pyn and CB[8]@Pyn have great potential to be used as slow-release agents.
危险品化学品经营许可证（带存储）