A redox-economic method for the direct coupling of olefins that uses an inexpensive iron catalyst and a silane reducing agent is reported. Thus, unactivated olefins can be joined directly to electron-deficient olefins in both intra- and intermolecular settings to generate hindered bicyclic systems, vicinal quaternary centers, and even cyclopropanes in good yield. The reaction is not sensitive t...

'Replaying the tape' is an intriguing 'would it happen again?' exercise. With respect to broad evolutionary innovations, such as photosynthesis, the answers are central to our search for life elsewhere. Photosynthesis permits a large planetary biomass on Earth. Specifically, oxygenic photosynthesis has allowed an oxygenated atmosphere and the evolution of large metabolically demanding creatures...

Hydrated electrons are among the strongest reductants known. Adding the ascorbate dianion as a sacrificial donor turns the photoionization of 9-anthrolate in water into a catalytic cycle for their in situ production with near-UV light (355 nm). The photoionization step is exclusively biphotonic and occurs via the first excited singlet state of the catalyst. Neither triplet formation nor any pho...

A well-defined cationic Ru-H complex catalyzes reductive etherification of aldehydes and ketones with alcohols. The catalytic method employs environmentally benign water as the solvent and cheaply available molecular hydrogen as the reducing agent to afford unsymmetrical ethers in a highly chemoselective manner.

There is growing interest in compounds containing functionalized E=E multiple bonds (E=Si, Ge, Sn, Pb) because of their potential to exhibit novel physical and chemical properties. However, compounds containing multiple functionalizations are rare, with scarcity increasing with increasing degree of substitution. The first ditetrelene R2 E=ER2 in which the E=E bond is substituted by four heteroa...

In other papers ofthis series (Holden, Pirie & Tracey, 1950; Holden, 1950a, b) the effects of a number of polysaccharases on leaf fibre are described. The only polysaccharase recognized in tobacco leaves in significant quantity is amylase (Frankenburg, 1946), and even this is not present in sufficient quantity to effect complete removal of starch on repeated prolonged incubation. It is convenie...

Phase-change access memory (PCM) appears to be the strongest candidate for next-generation high-density nonvolatile memory. The fabrication of ultrahigh-density PCM depends heavily on the thin-film growth technique for the phase-changing chalcogenide material. In this study, Ge2Sb2Te5 (GST) and GeSb8Te thin films were deposited by plasma-enhanced atomic layer deposition (ALD) method using Ge [(...

The mechanism of quenching of the excited state of terbium and europium complexes by electron-rich reductants occurs by formation of an exciplex involving the triplet excited state of the sensitising chromophore.

This review aims to present a global view of the efforts conducted to convert zeolites into efficient supports for the removal of heavy metal oxyanions. Despite lacking affinity for these species, due to inherent charge repulsion between zeolite framework and anionic species, zeolites have still received considerable attention from the scientific community, since their versatility allowed tailo...