COF-505 Brings Us the Weave

 

I’m sure you’re all aware of MOFs and COFs – Metal Organic Frameworks and Covalent Organic Frameworks. They’re porous nanomaterials put together from various atomic centres, linked by organic ligands. They’ve been toted as the answer to many of science’s great problems, from hydrogen storage to CO2 capture, and have been constructed in a whole manner of different structures and orientations. And, now, we have the weave.

Today I found this article on the Science Mag website describing research from Berkeley, which describes COF-505 – the first 3D covalent framework to be made by weaving together helical organic threads. The work was published online in Science this month, and can be viewed here. In the study, copper(I)-bisphenanthroline tetrafluoroborate was used to template the woven COF into this incredible new structure, and could be removed afterwards, keeping the framework intact.

The authors believe that this discovery will bring about the invention of molecular cloths which “combine unusual resiliency, strength, flexibility and chemical variability in one material”. It’s early days at the moment, but this looks like fascinating new research which could lead to great things.

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One metal centre, three different M-N bonds!

Why have one type of metal-nitrogen bond when you can have three? Well, a team from Michigan State University have done just that! A fascinating nitrogen analogue of the Schrock and Clark “yl-ene-yne” complex, W(CBut)(CHBut)(CH2But)(dmpe),  has been published in Chemical Science today.

nitridocompd

The compound and Schrock’s carbon analogue were both analysed using a combination of Mayer bond orders and Natural Resonance Theory (see above), which were both in good agreement and showed triple, double and single bonds to all be present in each compound.

The new compound unsurprisingly gave interesting reaction products with different electrophiles. Indeed, reactions with methyl iodide and acetic anhydride occur at the imido nitrogen, which may be predictable since you might expect a more negative charge to be located there. However, pivaloyl chloride reacts at the nitrido nitrogen atom, giving a rare example of a transition metal nitrido complex containing a carboxyl group on the nitrogen. This outcome may be down to sterics, but it would be very interesting to see the scope of reactivity with this new complex and other electrophiles.

All in all, this is a pretty cool new compound, and I’m sure we’ll see lots of interesting chemistry coming from it.

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Four New Elements Finally Fill Up Seventh Row

atom-resized

News just in! It has been announced today that the seventh row of the period table has finally been filled up, with elements 113, 115, 117 and 118 being verified by the International Union of Pure and Applied Chemistry  (IUPAC) on 30 December.

The body announced that a team of Russian and American scientists had provided sufficient evidence for elements  115, 117 and 118 to be added to the periodic table, and IUPAC awarded credit for element 113 to a group of Japanese researchers at the Riken Institute.

The elements are the first to be added since 2011, when elements 114 and 116 were added.

Kosuke Morita, who was leading the research at Riken, said his team now planned to “look to the unchartered territory of element 119 and beyond.”

IUPAC has now initiated the process of formalising names and symbols for these elements, temporarily named as ununtrium, (Uut or element 113), ununpentium (Uup, element 115), ununseptium (Uus, element 117), and ununoctium (Uuo, element 118). The groups credited for proving the existence of the elements are currently thinking of names for the elements, which will then be present to IUPAC to go under public review.

Like other super-heavy elements, these elements are artifically made and only exist for very short periods of time before decaying into more stable elements.

The chemistry community is abuzz with this news, and I’m sure we’re all very excited to find out what names are given to the final members of Period 7!

 

Image courtesy of chemistry.about.com

 

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The Science Events that Shaped 2015

As we enter a brand new year, not knowing what the chemical sciences might throw at us, it’s a good time to look back over the last year and see what the key science moments were in 2015.

Luckily, the Nature News website has put together a list of the major events which have taken place during the past 365 days for us to peruse.

Our most recent big event was of course the Climate Change Summit in Paris. The meeting was a great success, with more nations than ever before pledging to cut carbon emissions and keep global warming “well below” the 2 degrees previously predicted.

I’m sure we all remember when the New Horizon spacecraft flew close to Pluto back in July, revealing never-before-seen close-ups of the ex-planet’s surface. The complexity of the surfaces astounded scientists, and members of the public were dazzled by its beauty.

The CRISPR genome-editing system became big news in 2015, as it was used to edit non-viable human embryos by China. This spurred a huge amount of debate in the area, culminating in the International Summit on Human Gene Editing in December, which didn’t outran ban the use of CRISPR on human embryos, but decided it is not yet ready for this application. CRISPR has become increasingly popular throughout the year, as scientists try to use it to enhance crops and livestock and even cure human disease.

Ebola has been hitting the headlines since 2014, and this year a new vaccine, rVSV-ZEBOV,  was developed which offered near total protection against the disease. Further vaccines have been developed, including one for malaria which so far only offers 30% protection, and the first ever vaccine for the dengue virus was approved in Mexico. Polio vaccinations have proven to be more effective than ever, with the disease now being close to eradication.

In the 100th anniversary of Einstein’s general theory of relativity, headlines were hit when physicists published the most convincing proof yet that two objects, such as subatomic particles, could be linked. Einstein famously disliked this theory, as it breaks the golden rule that nothing can travel faster than the speed of light, but it could one day be used to build highly secure quantum internet.

In line with one of my previous posts, reproducibility has been a big topic in 2015. Many teams around the globe have been attempting to study the matter, with one study showing that two thirds of attempts to replicate psychology studies fail. Actions began to be taken throughout the year, such as the Wellcome Trust putting forwards its strategies to improve reproducibility.

The issue of sexism in science became a hotter topic than ever before this year, and the spotlight was shone on the issue as Tim Hunt made his controversial statement about sharing laboratories with women. His comments sent shockwaves throughout the globe, and thousands of female scientists took to social media to declare their outrage. There was also the shocking incident of UK evolutionary geneticist Fiona Ingleby being rejected for her paper by PLos ONE, as she needed “one or two” male co-authors to strengthen the article.

It’s been great to see science be so prominently in the public eye this past year, whether positively or negatively, and let’s hope 2016 gets more people talking about scientific issues.

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