Molecular printing - pp353 - 358

Adam B. Braunschweig, Fengwei Huo & Chad A. Mirkin

doi:10.1038/nchem.258

The direct transfer of molecules onto surfaces to form specific patterns has had a significant impact in a number of areas of science and technology, ranging from biomedical diagnostics to nanoelectronics. This Perspective compares and contrasts different lithographic approaches to molecular printing and considers future directions for this field.

Abstract - | Full Text - Molecular printing | PDF (729 KB) - Molecular printing

Subject Categories: Nanotechnology | Surface chemistry

Enantioselective protonation - pp359 - 369

Justin T. Mohr, Allen Y. Hong & Brian M. Stoltz

doi:10.1038/nchem.297

Chemical methods of achieving asymmetric protonation are classified according to reaction mechanism, with a view to developing a greater understanding of this most fundamental of asymmetric processes, and thus improving the potential for its application in synthesis.

Abstract - | Full Text - Enantioselective protonation | PDF (1,037 KB) - Enantioselective protonation

Subject Categories: Organic chemistry | Synthesis

Spin transition in a four-coordinate iron oxide - pp371 - 376

T. Kawakami, Y. Tsujimoto, H. Kageyama, Xing-Qiu Chen, C. L. Fu, C. Tassel, A. Kitada, S. Suto, K. Hirama, Y. Sekiya, Y. Makino, T. Okada, T. Yagi, N. Hayashi, K. Yoshimura, S. Nasu, R. Podloucky & M. Takano

doi:10.1038/nchem.289

Spin transitions — metal ions changing from high- to low-spin states — can be triggered by a range of stimuli and have normally only been observed in octahedrally coordinated ions. Now, a four-coordinate, square-planar iron(II) compound, SrFeO₂, exhibits such a spin transition, accompanied by a transition from an antiferromagnetic insulator to a ferromagnetic half-metal.

Abstract - | Full Text - Spin transition in a four-coordinate iron oxide | PDF (611 KB) - Spin transition in a four-coordinate iron oxide | Supplementary information

Subject Categories: Inorganic chemistry | Materials chemistry

See also: News and Views by Whangbo & Köhler

Sugar synthesis in a protocellular model leads to a cell signalling response in bacteria - pp377 - 383

Paul M. Gardner, Klaus Winzer & Benjamin G. Davis

doi:10.1038/nchem.296

Building artificial chemical systems that mimic the behaviour of cells could offer new insights into biological processes. Now, researchers show that by compartmentalizing the autocatalytic formose reaction inside lipid vesicles, and using small-molecule precursors as a 'metabolic' fuel, they can create a system that is capable of communicating with living bacterial cells.

Abstract - | Full Text - Sugar synthesis in a protocellular model leads to a cell signalling response in bacteria | PDF (400 KB) - Sugar synthesis in a protocellular model leads to a cell signalling response in bacteria | Supplementary information | Chemical compounds

Subject Categories: Chemical biology | Organic chemistry

See also: News and Views by Cooper & Cronin

A potential energy surface bifurcation in terpene biosynthesis - pp384 - 389

Young J. Hong & Dean J. Tantillo

doi:10.1038/nchem.287

Bifurcating reaction pathways are those for which a single transition-state structure leads to two separate products, and they have been seen previously in the reactions of certain small molecules. Now, calculations provide evidence for a pathway that bifurcates in the synthesis of a terpene — leading to distinctly different structures.

Abstract - | Full Text - A potential energy surface bifurcation in terpene biosynthesis | PDF (587 KB) - A potential energy surface bifurcation in terpene biosynthesis | Supplementary information

Subject Categories: Theoretical chemistry | Organic chemistry | Synthesis

Metal–nucleic acid cages - pp390 - 396

Hua Yang, Christopher K. McLaughlin, Faisal A. Aldaye, Graham D. Hamblin, Andrzej Z. Rys, Isabelle Rouiller & Hanadi F. Sleiman

doi:10.1038/nchem.290

Incorporating binding sites for metal ions into DNA strands that assemble into well-defined three-dimensional structures has enabled researchers to build metal-nucleic acid cages. There is potential for the geometry, pore size and chemistry of such materials to be easily tuned, which may prove useful for applications in molecular sensing and encapsulation.

Abstract - | Full Text - Metal–nucleic acid cages | PDF (693 KB) - Metal–nucleic acid cages | Supplementary information

Subject Categories: Materials chemistry | Supramolecular chemistry

See also: News and Views by Liu & Yan

Size-specific catalytic activity of platinum clusters enhances oxygen reduction reactions - pp397 - 402

Kimihisa Yamamoto, Takane Imaoka, Wang-Jae Chun, Osamu Enoki, Hideaki Katoh, Masahiro Takenaga & Atsunori Sonoi

doi:10.1038/nchem.288

Platinum nanoparticles are excellent catalysts, but maintaining that effectiveness at ever smaller particle sizes is crucial to make best use of the precious metal. Now, a dendrimer has been used as a template to make subnanometre clusters, with a defined number of atoms, that exhibit high catalytic activity.

Abstract - | Full Text - Size-specific catalytic activity of platinum clusters enhances oxygen reduction reactions | PDF (525 KB) - Size-specific catalytic activity of platinum clusters enhances oxygen reduction reactions | Supplementary information | Chemical compounds

Subject Categories: Catalysis | Nanotechnology

New insights into the structure and reduction of graphite oxide - pp403 - 408

Wei Gao, Lawrence B. Alemany, Lijie Ci & Pulickel M. Ajayan

doi:10.1038/nchem.281

The unusual properties of graphene make it a promising candidate for nanoelectronics applications, but it remains a difficult material to make. Now, on the basis of spectroscopic data that characterize the graphene-precursor graphite oxide, researchers have devised an efficient reduction process for the large-scale production of nearly pure, highly conductive graphene sheets.

Abstract - | Full Text - New insights into the structure and reduction of graphite oxide | PDF (425 KB) - New insights into the structure and reduction of graphite oxide | Supplementary information

Subject Categories: Materials chemistry | Nanotechnology

Drastic symmetry breaking in supramolecular organization of enantiomerically unbalanced monolayers at surfaces - pp409 - 414

Sam Haq, Ning Liu, Vincent Humblot, A. P. J. Jansen & Rasmita Raval

doi:10.1038/nchem.295

When a racemic mixture of tartaric acid is adsorbed on a Cu(110) surface, the (R,R) and (S,S) enantiomers separate to form enantiopure domains that cover equal amounts of the substrate. Repeating the experiment with just a small excess of one enantiomer, however, has a drastic effect on the surface assembly with only the majority isomer forming ordered superstructures.

Abstract - | Full Text - Drastic symmetry breaking in supramolecular organization of enantiomerically unbalanced monolayers at surfaces | PDF (741 KB) - Drastic symmetry breaking in supramolecular organization of enantiomerically unbalanced monolayers at surfaces | Supplementary information

Subject Categories: Supramolecular chemistry | Surface chemistry

See also: News and Views by Baddeley

Visualizing and identifying single atoms using electron energy-loss spectroscopy with low accelerating voltage - pp415 - 418

Kazu Suenaga, Yuta Sato, Zheng Liu, Hiromichi Kataura, Toshiya Okazaki, Koji Kimoto, Hidetaka Sawada, Takeo Sasaki, Kazuya Omoto, Takeshi Tomita, Toshikatsu Kaneyama & Yukihito Kondo

doi:10.1038/nchem.282

Electron energy-loss spectroscopy (EELS) is broadly used to examine chemical composition, but single-atom analysis is hampered by the damage caused by incident electrons. Now, with an EELS technique that does not cause such damage, single calcium atoms have been identified and various elemental analyses demonstrated using metallofullerene-doped nanotubes.

Abstract - | Full Text - Visualizing and identifying single atoms using electron energy-loss spectroscopy with low accelerating voltage | PDF (1,997 KB) - Visualizing and identifying single atoms using electron energy-loss spectroscopy with low accelerating voltage | Supplementary information

Subject Categories: Analytical chemistry | General chemistry