Volume 3 Issue 11, November 2011

The historical context in which a scientific paper is published is an important factor that should not be overlooked, suggest Qian Wang and Chris Toumey.

A tetra-intercalator compound that threads through a DNA double-helix to form a remarkably stable complex exhibits an unusual combination of sequence specificity and rapid association yet slow dissociation.

Activating caged reactive sites in proteins using mechanical force provides a powerful approach in the study of chemical reactions, and provides greater insight into which reactions are possible and their rates.

Catalyst particles for fluid catalytic cracking are vital for the oil-refinery industry, but their activity is hard to diagnose because of their inter- and intra-particle structural inhomogeneity. With fluorescence confocal microscopy and selective staining, one can now pinpoint the catalytic activity within single catalyst particles from an industrial reactor.

Proton migration on membranes is a crucial step in the bioenergetics of the cell. It has typically been regarded as slow successive proton transfers between ionizable moieties within the membrane, but recent measurements suggest fast lateral diffusion in the membrane's hydration layer.

Conformational control can be used to transmit information in the form of chirality over relatively long molecular distances and could be the key to the preparation of minimalistic synthetic mimics of biological systems.

Topological insulators — insulators or semiconductors with metallic states present at their boundaries — are the 'rising stars' of condensed-matter physics. This Perspective introduces these materials and their properties, and looks at the challenges and opportunities the community faces.

The flow of vibrational energy into reactants and out of products plays a critical role in nearly every chemical reaction. Here, a time-resolved ultrafast microscopic map of energy flow is provided for a thermal bimolecular chemical reaction that takes place in dichloromethane, a typical organic solvent.

2,2′-bipyridine ligands coordinate to metals to form chiral propeller-like complexes. Now, this chirality is shown to be controlled by the coordination of 2,2′-bipyridine ligands that bear helical oligopeptides, which incorporate chiral amino acids at positions remote from the metal centre. This chirality is further translated, via the metal centre, to other achiral-oligopeptide-containing ligands.

Insight into the active zeolitic domains of catalyst particles used in fluid catalytic cracking is limited by the particles' complex nature, but is crucial to improving these billion dollar catalysts. Now, a staining method allows confocal fluorescence microscopy to probe within single catalyst particles, and correlate Brønsted acidity distributions to catalytic activity.

Cellular membrane lipids play key roles in cell regulation. Here, an environmentally sensitive fluorophore is attached to a protein that binds to a key signalling lipid to produce a membrane lipid sensor. This strategy allows sensitive, quantitative, spatiotemporal imaging of the lipid concentration in mammalian cells.

Molecules that bind to DNA for extended periods can modulate its transcription or other biological processes. Kinetic studies on the non-covalent complex formed by a threading tetra-intercalator and a DNA double-helix have now revealed a multi-step association, and a particularly slow dissociation leading to sequence specificity and a 16-day half-life.

Multiple redox reaction pathways exist in proteins containing several cysteines. A technique termed mechanical uncaging is now demonstrated, allowing the release of a single reactive cysteine within a protein and the unequivocal observation of subsequent thiol/disulfide exchanges. Mechanical uncaging of reactive groups is useful for studying chemical kinetics in a synchronized manner.

At water's surface, its network of hydrogen-bonds is abruptly interrupted, conferring distinct properties on interfacial water from bulk water. Understanding aqueous interfaces is essential for many environmental, technological and biophysical systems, and now the pathways and rates of energy transfer at the water/air interface are elucidated using a surface-specific ultrafast spectroscopic technique.

Stereoselective Suzuki–Miyaura cross-coupling reactions involving non-benzylic secondary alkylboronates are notoriously challenging. Here, an enantioselective synthesis of 1,1-diboronyl compounds using asymmetric conjugate borylation, followed by chemoselective mono cross-coupling with inversion at the diboron centre, is used to produce highly enantioenriched benzylic or allylic boronates, which themselves are useful reagents for a number of processes.

Calcium is found throughout the solar system, the Earth's crust and oceans, and is an essential constituent of cells, shells and bones — yet it is curiously scarce in the upper atmosphere. John Plane ponders on this 25-year-old mystery.