This review covers all aspects of 9-borafluorene chemistry, from the first attempted synthesis in 1960 to the present. This class of molecules consists of a tricyclic system featuring a central antiaromatic BC 4 ring with two fused arene groups. The synthetic routes to all 9-borafluorenes and their adducts are presented. The Lewis acidity and photophysical properties outlined demonstrate potential utility as sensors and in electronic materials. The reactivity of borafluorenes reveals their prospects as reagents for the synthesis of other boron-containing molecules. The appealing traits of 9-borafluorenes have stimulated investigations into analogues that bear different aromatic groups fused to the central BC 4 ring. Finally, we offer our views on the challenges and future of borafluorene chemistry.

The reactions of 9-borafluorenes with organic azides result in either the insertion of the α-nitrogen and elimination of N2 or the insertion of the γ-nitrogen to generate the corresponding phenanthrene analogues with boron and nitrogen in the 9- and 10-positions, respectively.

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We report a strategy to integrate atomically dispersed iron within a heterogeneous nitrogen-doped carbon (N-C) support, inspired by routes for metalation of molecular macrocyclic iron complexes. The N-C support, derived from pyrolysis of a ZIF-8 metal–organic framework, is metalated via solution-phase reaction with FeCl2 and tributyl amine, as a Brønsted base, at 150 °C. Fe active sites are characterized by 57Fe Mössbauer spectroscopy and aberration-corrected scanning transmission electron microscopy. The site density can be increased by selective removal of Zn2+ ions from the N-C support prior to metalation, resembling the transmetalation strategy commonly employed for the preparation of molecular Fe-macrocycles. The utility of this approach is validated by the higher catalytic rates (per total Fe) of these materials relative to established Fe-N-C catalysts, benchmarked using an aerobic oxidation reaction.

Household smart devices -internet-connected thermostats, lights, door locks, and more -have increased greatly in popularity. These devices provide convenience, yet can introduce issues related to safety, security, and usability. To better understand device owners' recent negative experiences with widely deployed smart devices and how those experiences impact the ability to provide a safe environment for users, we conducted an online, survey-based study of 72 participants who have smart devices in their own home. Participants reported struggling to diagnose and recover from power outages and network failures, misattributing some events to hacking. For devices featuring built-in learning, participants reported difficulty avoiding false alarms, communicating complex schedules, and resolving conflicting preferences. Finally, while many smart devices support end-user programming, participants reported fears of breaking the system by writing their own programs. To address these negative experiences, we propose a research agenda for improving the transparency of smart devices.