Möbius aromaticity and antiaromaticity in expanded porphyrins - pp113 - 122

Zin Seok Yoon, Atsuhiro Osuka & Dongho Kim

doi:10.1038/nchem.172

Molecules with a Möbius geometry are not found in nature, and have thus been a target for synthetic chemists since the first prediction of its existence in 1964. This review summarizes recent successes in synthesizing these fascinating forms, with particular emphasis on expanded porphyrins.

Abstract - | Full Text - Möbius aromaticity and antiaromaticity in expanded porphyrins | PDF (1,133 KB) - Möbius aromaticity and antiaromaticity in expanded porphyrins

Subject Categories: Organic chemistry | General chemistry

A tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface - pp123 - 127

Yu Han, Daliang Zhang, Leng Leng Chng, Junliang Sun, Lan Zhao, Xiaodong Zou & Jackie Y. Ying

doi:10.1038/nchem.166

Porous materials with very different pore sizes and structures are commonly used for various applications. But although bicontinuous pore networks — with two interwoven yet unconnected channels — have been reported, tricontinuous structures have so far only been predicted theoretically. Now, researchers have prepared a mesoporous silica with three identical, interpenetrating channels.

Abstract - | Full Text - A tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface | PDF (2,000 KB) - A tri-continuous mesoporous material with a silica pore wall following a hexagonal minimal surface | Supplementary information

Subject Categories: Inorganic chemistry | Materials chemistry

See also: News and Views by Ryoo

A unique approach to aldol products for the creation of all-carbon quaternary stereocentres - pp128 - 132

Jaya Prakash Das, Helena Chechik & Ilan Marek

doi:10.1038/nchem.131

The enantioselective construction of quaternary stereocentres, particularly those with all-carbon substituents, is a challenging problem in asymmetric synthesis. It has now been shown that an alternative retrosynthesis of aldol products provides an opportunity to form such stereocentres with a reaction that creates three new carbon–carbon bonds in a single step.

Abstract - | Full Text - A unique approach to aldol products for the creation of all-carbon quaternary stereocentres | PDF (384 KB) - A unique approach to aldol products for the creation of all-carbon quaternary stereocentres | Supplementary information | Chemical compounds

Subject Categories: Organic chemistry | Organometallic chemistry | Synthesis

Activating catalysts with mechanical force - pp133 - 137

Alessio Piermattei, S. Karthikeyan & Rint P. Sijbesma

doi:10.1038/nchem.167

Latent catalysts are usually activated by heating them or adding an external chemical agent, but now it has been shown that mechanical force is also an option in some instances. Ultrasound can be used to dissociate polymeric ligands from metal-containing complexes to reveal the innate catalytic ability of one of the two fragments.

Abstract - | Full Text - Activating catalysts with mechanical force | PDF (331 KB) - Activating catalysts with mechanical force | Supplementary information | Chemical compounds

Subject Categories: Catalysis | Organometallic chemistry | Polymer chemistry

See also: News and Views by Rathore & Nelson

Using small molecules to facilitate exchange of bicarbonate and chloride anions across liposomal membranes - pp138 - 144

Jeffery T. Davis, Philip A. Gale, Oluyomi A. Okunola, Pilar Prados, Jose Carlos Iglesias-Sánchez, Tomás Torroba & Roberto Quesada

doi:10.1038/nchem.178

The transport of bicarbonate anions across cell membranes by proteins is an important biological process, and if not regulated properly it can lead to cystic fibrosis and heart disease. Now, it has been shown that 'small' molecules can also promote efficient bicarbonate transport across lipid membranes and could be used to probe this process.

Abstract - | Full Text - Using small molecules to facilitate exchange of bicarbonate and chloride anions across liposomal membranes | PDF (640 KB) - Using small molecules to facilitate exchange of bicarbonate and chloride anions across liposomal membranes | Supplementary information | Chemical compounds

Subject Categories: General chemistry | Supramolecular chemistry

A diiron(iv) complex that cleaves strong C–H and O–H bonds - pp145 - 150

Dong Wang, Erik R. Farquhar, Audria Stubna, Eckard Münck & Lawrence Que, Jr

doi:10.1038/nchem.162

Carbon–hydrogen bonds are strong and stable, rarely succumbing to the activation attempts of chemists. Certain bacteria are able to metabolize methane using a diiron-centred enzyme, but synthetic analogues have had much less reactivity. Now, an oxo-bridged diiron complex has been shown to have extremely high activity towards C–H bonds.

Abstract - | Full Text - A diiron(iv) complex that cleaves strong C–H and O–H bonds | PDF (444 KB) - A diiron(iv) complex that cleaves strong C–H and O–H bonds | Supplementary information

Subject Category: Inorganic chemistry

See also: News and Views by Goldman

G-quadruplex self-assembly regulated by Coulombic interactions - pp151 - 155

David González-Rodríguez, Joost L. J. van Dongen, Martin Lutz, Anthony L. Spek, Albertus P. H. J. Schenning & E. W. Meijer

doi:10.1038/nchem.177

Self-assembly of discrete and well-defined supramolecular structures often requires a delicate balance of non-covalent forces such as hydrogen bonding and metal–ligand interactions. Now, by studying the formation of G-quadruplexes, it has been shown that the Coulombic energy associated with the separation of ion pairs can also be used to precisely regulate self-assembly processes.

Abstract - | Full Text - G-quadruplex self-assembly regulated by Coulombic interactions | PDF (1,123 KB) - G-quadruplex self-assembly regulated by Coulombic interactions | Supplementary information | Chemical compounds

Subject Category: Supramolecular chemistry

Sequence-independent and rapid long-range charge transfer through DNA - pp156 - 159

Kiyohiko Kawai, Haruka Kodera, Yasuko Osakada & Tetsuro Majima

doi:10.1038/nchem.171

The presence of adenine–thymine base pairs in DNA duplexes significantly reduces their electrical conductivity. However, by replacing adenine with a closely related analogue that does not disturb the normal complementary base pairing, it is possible to make duplexes that can transfer charge efficiently without having to use only guanine–cytosine base pairs.

Abstract - | Full Text - Sequence-independent and rapid long-range charge transfer through DNA | PDF (828 KB) - Sequence-independent and rapid long-range charge transfer through DNA | Supplementary information

Subject Categories: Physical chemistry | Photochemistry

See also: News and Views by Genereux & Barton

Chiral imprinting of palladium with cinchona alkaloids - pp160 - 164

L. Durán Pachón, I. Yosef, T. Z. Markus, R. Naaman, D. Avnir & G. Rothenberg

doi:10.1038/nchem.180

A metallo-organic hybrid material prepared by reduction of a palladium salt in the presence of cinchona alkaloids shows moderate enantioselectivity in organic transformations. The metal retains some chiral character after extraction of the dopant, selectively readsorbing the original alkaloid and showing different responses to clockwise and anticlockwise circularly polarized light.

Abstract - | Full Text - Chiral imprinting of palladium with cinchona alkaloids | PDF (363 KB) - Chiral imprinting of palladium with cinchona alkaloids | Supplementary information | Chemical compounds

Subject Categories: Catalysis | Materials chemistry