Supra-herbicide based on sunlight-opened macrocycle gate with reduced toxicity

Scheme 1. Scheme of NP5-PQ supra-herbicide fabrication, light-controlled release properties (a) and recovery of herbicidal activity (b). [Display omitted] •The supra-herbicide could reduce the toxicity of PQ via molecular shielding effect.•Under the exposure of sunlight, PQ released and the herbicidal activity was recovered owing to the fracture of NP5 macrocycles.•This is first example of supra-herbicide based on sunlight-opened macrocycle gate, which could reduce the toxicity of PQ without losing herbicidal activity. Supramolecular herbicide was fabricated through the host–guest complexation of prism[5]arene (NP5) and paraquat (PQ).For the supra-herbicide, the toxicity of PQ could be reduced by molecular shielding effect. Under exposure to sunlight, NP5 gate was opened to release PQ and the herbicidal activity was recovered.