Chemical Communications Blog

Scientists in Austria who have redesigned the active site of an enzyme to switch its regioselectivity may have latched onto a new way to make molecules that are important for infant formula. The engineered enzyme is almost identical to the original, it just catalyses a slightly different reaction to its twin.

Sialylated human milk oligosaccharides play an important role in infant health and development. They occur naturally in breast milk, but synthetic sialylated oligosaccharides are also in demand to enrich infant formula and other nutraceutical products.

Read the full article in Chemistry World»

Read the original journal article in ChemComm – it’s free to access until 27th April:
Complete switch from α-2,3- to α-2,6-regioselectivity in Pasteurella dagmatis β-D-galactoside sialyltransferase by active-site redesign
Katharina Schmölzer, Tibor Czabany, Christiane Luley-Goedl, Tea Pavkov-Keller, Doris Ribitsch, Helmut Schwab, Karl Gruber, Hansjörg Weber and Bernd Nidetzky  
Chem. Commun., 2015,51, 3083-3086
DOI: 10.1039/C4CC09772F, Communication

Chemists in the UK have created the unique trimetallic complex {(^Ar’NacNac)Zn}₂Hg. At the molecule’s heart lies a Zn–Hg–Zn unit – the first example of a bond between two different group 12 metals. What’s more, this metal chain is also the first example of catenation between group 12 elements other than just mercury. And if that wasn’t quirky enough for you, it is also a rare instance of zinc in the +1 oxidation state.

To make the compound, Philip Mountford, from the University of Oxford, and colleagues reduced (^Ar’NacNac)ZnI with a potassium–mercury amalgam. The team is now exploring the chemistry of {(^Ar’NacNac)Zn}₂Hg and its intermetallic homologues.

Read this article in Chemistry World»

Read the original journal article in ChemComm:
Synthesis, molecular and electronic structure, and reactions of a Zn–Hg–Zn bonded complex
Matthew P. Blake, Nikolas Kaltsoyannis and Philip Mountford  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C5CC00637F, Communication

Curcumin is top of the ingredients list for a highly porous metal–organic framework (MOF) being developed by scientists in China that demonstrates a unique co-release drug delivery system.

MOFs have shown huge potential as drug carriers thanks to their large voids capable of encapsulating a wide variety of guest molecules. However, they are typically built from expensive, petrochemical-derived organic linkers, which, unfortunately, are not biocompatible. To overcome this, a team led by Guangshan Zhu, of Jilin University, has constructed a MOF exclusively from biologically friendly zinc ions and bioactive curcumin – the yellow pigment in the popular Indian spice turmeric, known for its potent anti-cancer properties.

Read the full article in Chemistry World»

Read the original journal article in ChemComm – it’s free to access until 13th April:
A highly porous medical metal–organic framework constructed from bioactive curcumin
Hongmin Su, Fuxing Sun, Jiangtao Jia, Hongming He, Aifei Wang and Guangshan Zhu  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C4CC10159F, Communication

The discolouration rate of a fluorescent dye can act as a visual marker for changes in hydrogen bonding environment, new research shows.

Colourless spiropyrans undergo ring opening to form brightly coloured merocyanines on exposure to UV light. Merocyanines are thermally unstable and relax back to the colourless spiropyrans over time. The merocyanines designed by Simone Ciampi, from the University of Wollongong, Australia, and his colleagues contain a catechol group that can form intramolecular hydrogen bonds, which stabilises the open form and slows down discolouration. However, polar solvents can out-compete intramolecular hydrogen bond formation, and speed up discolouration. In this way, Ciampi’s team were able to visualise the hydrogen bonding character of solvents by adding their dye and observing the rate at which it discoloured.

Read the full article in Chemistry World»

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Decoloration rates of a photomerocyanine dye as a visual probe into hydrogen bonding interactions
Simone Ciampi, Paul K. Eggers, Naomi L. Haworth, Nadim Darwish, Pawel Wagner, Michelle L. Coote, Gordon G. Wallace and Colin L. Raston  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C4CC09857A, Communication

A simple and effective procedure to incorporate strongly-emitting inorganic clusters into nematic liquid crystals has been reported by a team from France. By combining the supramolecular paradigms of host–guest chemistry and electrostatic interactions the team have overcome previously insurmountable limitations of liquid crystalline materials.

Liquid crystals, which exhibit long-range directional order but also flow like a liquid, are a prominent feature of modern technology. They are commonly used as temperature sensors and their nematic phase is an integral component in liquid crystal display (LCD) technology.

Read the full article in Chemistry World»

Read the original journal article in ChemComm – it’s free to access until 19th March:
From metallic cluster-based ceramics to nematic hybrid liquid crystals: a double supramolecular approach
Susanta K. Nayak, Maria Amela-Cortes, Claire Roiland, Stéphane Cordier and Yann Molard  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C4CC10085A, Communication

Scientists in France and Germany have made use of DNA as part of a catalytic system for various enantioselective alkylations and addition reactions.

DNA has emerged as an innovative way of controlling the chirality of a reaction product; by binding catalysts in such a way that one enantiomer is preferentially generated. The chiral nature of the helix makes it ideal for asymmetric catalysis. However, this field of research is still in its infancy…

Read the full article in Chemistry World»

Read the original journal article in ChemComm – it’s free to access until 19th March:
DNA-cellulose: an economical, fully recyclable and highly effective chiral biomaterial for asymmetric catalysis
Erica Benedetti, Nicolas Duchemin, Lucas Bethge, Stefan Vonhoff, Sven Klussmann, Jean-Jacques Vasseur, Janine Cossy, Michael Smietana and Stellios Arseniyadis  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C4CC10190A, Communication

Reusable colour-changing sticky labels that act as a cheap and easy way to check the activity of photocatalysis-based self-cleaning glass have been designed by scientists in the UK.

Interest in self-cleaning technologies, including semiconductor photocatalysis (SPC), has been on the increase since the commercialisation of self-cleaning glass by Pilkington in 2001. However, SPC, a process by which light activation of a surface coating, usually titanium dioxide, facilitates the breakdown of organic dirt, is difficult to measure as most coatings are invisible to the eye.

Read the full article in Chemistry World»

Read the original journal article in ChemComm – it’s free to access until 12th March:
Smart, reusable labels for assessing self-cleaning films
A. Mills and N. Wells  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C4CC09734C, Communication

Building graphene from carefully-modified superbenzene segments has been proposed as a way to help graphene overcome a major stumbling block limiting its application in electronic devices – by opening its bandgap to make it a true semiconductor. 

Intrinsically, graphene is a semimetal with no bandgap. Boron nitride can afford graphene the electronic properties desired for atomically thin circuits. However, positioning these boron nitride-groups in just the right places to properly regulate electron flow through graphene is difficult. 

Read the full article in Chemistry World» 

Read the original article in ChemComm – it’s free to access until 11th March:
Synthesis, structure and properties of C3-symmetric heterosuperbenzene with three BN units
Xiao-Ye Wang, Fang-Dong Zhuang, Xin-Chang Wang, Xiao-Yu Cao, Jie-Yu Wang and Jian Pei  
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C4CC10105G, Communication