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Bees, one of the most vital pollinators in the ecosystem and agriculture, are currently threatened by neonicotinoids. To explore the molecular mechanisms of neonicotinoid toxicity to bees, the different binding modes of imidacloprid, thiacloprid, and flupyradifurone with nicotinic acetylcholine receptor (nAChR) α1β1 and cytochrome P450 9Q3 (CYP9Q3) were studied using homology modeling and molecular dynamics simulations. These mechanisms provided a basis for the design of compounds with a potential low bee toxicity. Consequently, we designed and synthesized a series of triazinone derivatives and assessed their bioassays. Among them, compound 5a not only displayed substantially insecticidal activities against Aphis glycines (LC 50 = 4.40 mg/L) and Myzus persicae (LC 50 = 6.44 mg/L) but also had low toxicity to Apis mellifera . Two-electrode voltage clamp recordings further confirmed that compound 5a interacted with the M. persicae nAChR α1 subunit but not with the A. mellifera nAChR α1 subunit. This work provides a paradigm for applying molecular toxic mechanisms to the design of compounds with low bee toxicity, thereby aiding the future rational design of eco-friendly nicotinic insecticides.

Low-dimensional organic-inorganic metal halides (LOMHs) recently have attracted much attention due to their tunable crystal structures and excellent photoelectric properties. The configuration and arrangement of organic cations in LOMHs have significant effect on the structure of inorganic frameworks and luminescence properties. In this work, we systematically explored the "spatial effect" and "hydrogen bonding effect" of organic cations on the structure and properties of LOMHs, by synthesizing three LOMHs including (N-AD)PbCl 4 , (N-AD) 2 Pb 2 Br 7, and (N-AD) 4 Pb 3 I 12 (N-AD: N-acetylethylenediamine, C 4 H 10 N 2 O). Specifically, (110)-oriented two-dimensional (N-AD)PbCl 4 and (N-AD) 2 Pb 2 Br 7 with manifest blue-white emissions, originating from the free excitons (FEs) and self-trapped excitons (STEs), respectively. The UV-pumped light-emitting diode (LED)-based on (N-AD) 2 Pb 2 Br 7 was prepared, and the highest color rendering index (CRI) and correlated color temperature (CCT) were up to 80 and 4484 K, respectively. This proves its potential application in solid-state lighting.