Unexpectedly, the 5‐dehydroquinoline radical cation was formed in the gas phase from the 5‐iodo‐8‐nitroquinolinium cation upon ion‐trap collision‐activated dissociation. This reaction involves the cleavage of a nitro group to generate an intermediate monoradical, namely, the 8‐dehydro‐5‐iodoquinolinium cation, followed by rearrangement through abstraction of a hydrogen atom from the protonated nitrogen atom by the radical site. Dissociation of the rearranged radical cation through elimination of an iodine atom generates the 5‐dehydroquinoline radical cation. The mechanism was probed by studying isomeric biradicals and performing quantum chemical calculations. The 5‐dehydroquinoline radical cation showed greater gas‐phase reactivity toward dimethyl disulfide, cyclohexane, and allyl iodide than the isomeric 5,8‐didehydroquinolinium cation, which is more reactive than the isomeric 5,8‐didehydroisoquinolinium cation studied previously. All three isomers have a 1,4‐biradical topology. The order of reactivity is rationalized by the vertical electron affinities of the radical sites of these biradicals instead of their widely differing singlet–triplet splittings.

Polymer‐based magnetic particles have been widely used for the separation of biological samples including nucleic acids, proteins, virus, and cells. Existing magnetic particles are almost prepared by coating polymers on magnetic nanoparticles (NPs). However, this strategy usually encounters the problem of poor magnetic NPs loading capacity. Here, a series of nanofractal magnetic particles (nanoFMPs) synthesized by a strategy of mediator monomer regulated emulsion interfacial polymerization is presented, which allows effective magnetic NPs loading and show efficient nucleic acid separation performance. The mediator monomers facilitate the dispersion of magnetic NPs in internal phase to achieve higher loading, and the hydrophilic monomers use electrostatic interactions to form surface nanofractal structures with functional groups. Compared with magnetic particles without nanofractal structure, nanoFMPs exhibit a higher nucleic acid extraction capability. This strategy offers an effective and versatile way for the synthesis of nanoFMPs toward efficient separation in various fields from clinical diagnosis to food safety and environmental monitoring.

Microwave-enhanced hydrogen production. A new technology toward hydrogen society and achieving carbon neutrality.