Volume 3 Issue 8, August 2011

The collision of an atom and a diatomic molecule may sound like a simple process but it has long been studied to understand the inherent intricacies of collisional energy transfer. Now, experiments carried out in unprecedented detail on the scattering of NO by Ar have revealed further complexity: parity-dependent quantum interference effects.

The synthesis and biological investigation of a family of natural products and unnatural analogues illustrates the importance of considering both form and function in the planning of any synthesis.

Carborane substituents — rather than alkyl or aryl groups — have now been used to tune ligand properties. Attaching a carborane cluster to a ligand through either a carbon or a boron atom markedly changes its coordination behaviour without altering its steric profile.

Methanol — an important potential fuel and synthetic building block — can be produced via the hydrogenation of carbonates and carbamates using a pincer ruthenium(II) catalyst.

DNA origami tiles with complementary shapes have been designed and assembled into large nanostructures through the geometrically controlled stacking of their helices.

When cells interact with an artificial surface, the result is a rapidly evolving and complex interface. This Perspective discusses how expressing the properties of both the cell and the substrate in chemical terms can aid in future material design. We also explore the importance of using multifunctional surfaces with quantitative, dynamic capabilities.

Rather than tuning metal–ligand interactions using carbon-based substituents, the effect of icosahedral carborane moieties — boron-rich clusters — on the coordination chemistry of phosphine–thioether ligands has been investigated. Depending on the positional attachment of the sulfur atom, the carboranes acted as either strong electron-withdrawing or strong electron-donating substituents.

Differential cross sections for the rotationally inelastic scattering of NO by Ar are reported with unprecedented quantum-state resolution. The experiments give important details about the mechanism of this fundamental collisional process, providing evidence for a parity-dependent quantum-mechanical interference effect.

A long-standing problem with the RNA-world hypothesis is that enzyme-free replication of RNA strands has not been demonstrated. Here, immobilization of a template strand and periodic replacement of a solution containing activated nucleotides allows the copying of unmodified RNA sequences containing any of the four natural nucleobases in near-quantitative yield.

Producing methanol — useful as both a fuel and a synthetic building block — from carbon monoxide and carbon dioxide has been achieved using homogeneous catalytic hydrogenation of carbonates, carbamates and formates. The catalyst is a dearomatized ruthenium(II) pincer complex and the reaction proceeds efficiently under mild conditions.

The daphnane diterpene orthoesters constitute a structurally fascinating family of natural products that exhibit remarkable and potent biological activities. A gateway strategy designed to provide general synthetic access to and biological evaluation of natural and non-natural daphnanes is described and used for yuanhuapin analogues.

Multiple specific binding interactions have typically been created from DNA using Watson–Crick complementarity. Now, diverse bonds have also been obtained through the geometric arrangement of blunt-end stacking interactions. Two approaches to specific interactions — binary and shape coding — are demonstrated. The thermodynamics and binding rules of the resulting ‘stacking bonds’ are explored.

Enzymes are capable of modifying complex organic structures with exquisite selectivity. Understanding these processes could help in the development and production of new bioactive compounds. Here, a complete reconstitution of tailoring steps in tirandamycin biosynthesis shows that two enzymes repeatedly exchange substrates to achieve several different oxidations en route to this family of antibiotic compounds.

An important goal for the improvement of certain heterogeneous catalysts is to decrease the amount of platinum required while maintaining high catalytic activity. Now, the practical synthesis of a stable catalyst consisting of isolated single platinum atoms anchored onto iron oxide nanocrystallites has been developed that exhibits high activity for CO oxidation.

Acyclic azomethine imines would be useful prochiral electrophiles in catalytic asymmetric reactions, but their generation often requires harsh conditions. Here, they are generated under mild conditions in the presence of an axially chiral dicarboxylic acid, with the chiral counterion (the conjugate base) then directing an enantioselective reaction with a diazoacetate nucleophile.

Thomas Rauchfuss marvels at the diversity of sulfur reactivity. Although it poisons most industrial catalysts, it adopts many forms in nature and takes on a variety of biological roles — including that of a biocatalyst.