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In this work, we report the rapid photoreductive debromination of decabromodiphenyl ether (BDE209) byTiO2. The degradation of BDE209 is a stepwise process, and the bromines at the ortho positions are much more susceptible than those at the para positions. The photocatalytic degradation kinetics of BDE209 was further investigated under different reaction conditions (various solvents, in the presence of H2O, acids, or bases). A possible photoreductive debromination pathway was proposed on the basis of the identified reaction intermediates and density functional theory (DFT). This study provides a potential application of photocatalysis in removal of PBDE contamination.

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A theoretical investigation of the He-PH ( 3 − ) complex is presented. We perform ab initio calculations of the interaction potential energy surface and discuss its error bounds with relevance to cold collisions, and we carry out accurate calculations of bound energy levels of the complex including the molecular fine structure and magnetic-field effect. We find the potential has two shallow minima and supports ten and 13 bound levels in complex with 3 He and 4 He, respectively. Based on the potential the quantum scattering calculations are then implemented for elastic and inelastic cross sections of the magnetically trappable low-field-seeking state of PH ( 3 − ) in collision with 3 He atom. The cold-collision properties and the influence of the external magnetic field as well as the effect of the uncertainty of interaction potential on the collisionally induced Zeeman relaxation are explored and discussed in detail. The ratio of elastic to inelastic cross sections is large over a wide range of collision energy, magnetic field, and scaling factor of the potential, so that helium buffer-gas loading and evaporative cooling of PH is a good prospect.

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Polybrominated diphenyl ethers (PBDEs) have aroused global environmental concerns because of their toxicity and ubiquitousness in the biological and environmental systems. It is important to find an efficient method for their decontamination and to understand their chemical transformation in the environment. Here, we report that decabromodiphenyl ether (BDE209) undergoes efficient reductive debromination reactions under visible-light irradiation (≥ 420 nm) in the presence of various carboxylate anions that are common in the environmental media. The debromination reactions occur in a stepwise manner, producing a series of lower brominated PBDE congeners. Solvent-derived radials are observed by spin-trapping electron spin resonance (ESR) experiments during the photoreaction. Further experiments by the UV-vis absorption and isothermal titration calorimetry (ITC), combined with theoretical calculations, reveal a new photochemical debromination pathway based on the halogen binding interaction. According to this pathway, the formation of halogen-binding-based complex between PBDE and carboxylate enables the visible-light absorption and debromination of PBDEs, although neither PBDEs nor carboxylates have visible-light absorption. The halogen-bond-based photochemical debromination could find its application for our better understanding of the transformation process of PBDEs in the environment.

The near infrared (NIR) absorption and average particle size of gold nanostars (GNSs) can be precisely controlled by varying the molar ratios of cucurbit[7]urils (CB[7]) and GNSs in aqueous solution. GNSs modified with CB[7] achieved high cargo loading with thermally activated release upon the NIR laser irradiation.

In this work, we report the fast and ultrasensitive detection of a nerve agent simulant in the gas phase, diethyl chlorophosphate (DCP), by using carbazole-based nanofibers from 1. When exposed to trace DCP, the formed pyridine-phosphorylated product in 1 nanofibers can cause amplified ratiometric fluorescence responses, i.e., amplified fluorescence quenching via quenching excitons within the diffusion length of 1 nanofibers and simultaneously amplified turn-on fluorescence responses via harvesting excitons within the diffusion length to give the intramolecular charge transfer (ICT) emission at a longer wavelength. On the basis of these amplified ratiometric fluorescence responses, detection of DCP with fast response (ca. 3 s), ultrasensitivity (4 ppb), and improved selectivity is achieved.