Interaction of pesticide pyroquilon with two different cucurbit[n]uril

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.