tl, dr April

news · 3 years ago
by Krisztián Niesz
Hi Folks! So many exciting discoveries have happened and surprising news has come to light in April, it was really hard to decide what to cover here. This is really only the top few on my list. Hope you enjoy, and will learn more about them! Exciting News on Graphene Front First real “Inorganic Grignard Reagent” Prepared Perovskites for Photovoltaics & Lasers Once Again: Nanoparticles for Enhanced Drug Delivery Multibillion Dollar Deals Between Pharma Giants 1) Finally, it seems that the day has arrived in graphene technology with production stepping up to meet the increasingly growing demand for high quality materials. And this month there is not only one, but already two exciting stories to tell. At first let me start with Samsung, who earlier this month announced that they have discovered a breakthrough technology towards mass production of single-crystal wafer-sized graphene sheets.1 The significance stands in large size, high quality and low defect concentration that combined directly allow using these materials in applications, such as graphene-based field effect transistors (GFET). The basic science that allows the unidirectional growth of graphene sheet includes using H-terminated germanium (110) substrate surfaces supported on silicon wafers, which, because of the weak interaction, not only directs the growth, but can be fairly easily removed from the graphene layer and reused later. Although there are still plenty of scientific issues to be solved (e.g. tuning the electronic properties of graphene), this breakthrough in production can/will provide a significant push to the field. The other related news is associated to scientists from the Max Planck Institute for Polymer Research in Mainz, Germany, who used electrochemical exfoliation of graphite into graphene flakes in electrolytes containing inorganic salts.2 Beside the fact that the process is environmentally more friendly and safer than the usual acid-based one, it also provides great hopes toward mass production. 16.3 g of graphene flakes, with 1-3 layers, were generated in 30 minutes. The only downside of the process is that it generates very small flakes in the mm scale across, therefore the applications are limited. It is currently not suitable for providing materials for example for transparent flexible electrodes, which requires high-quality and defect-free materials. 2) Grignard reagents, or organomagnesium compounds (e.g. R-MgBr) are frequently used in organometallic chemical reactions to transfer and build in an organic group, bound to magnesium, into another organic molecule. International team of scientists have now discovered an analogue method to this, and formed bimetallic compounds using never before reported “inorganic Grignard reagents”.3 The IGR is built up of a two-coordinate Mn(0) complex, which is unprecedented because most transition metals require four or more bonds to provide stability. Following this new concept the researchers were able to produce Mn(I) dimers and a hetero-bimetallic Mn(II)-Cr(0) complex as well, that was also tested to act as a reducing agent with unsaturated organic compounds. 3) Recently it was reported the first time that perovskite materials (ABO3) could emit laser light at high efficiency.4 Researchers at the Swiss Federal Institute of Technology have worked out a low temperature synthesis method to produce organic lead halide perovskites (CH3NH3PbX3 where X = Cl, Br, I) that can convert ~ 70% of the adsorbed light into emitted light in an easily tunable (from IR through UV wavelength) manner. The fact that the material obtains an outstanding luminescent efficiency instantly makes researchers think about promising applications, such as light emitting diodes and thin film photovoltaics in solar cells. The next step to solve for LED applications is to work out how to electrically excitate these materials. 4) It’s been one of the hottest topics in nanomedicines for some time, but only recently it has become possible to use nanoparticles as drug delivery agents for more than two drugs.5 And what makes it possible is the wonder of synthetic polymer chemistry. MIT scientists have developed a smart way to create a polymer nanoparticle that can carry three therapeutic agents (doxorubicin, camptothecin and cisplatin) in a precise molar ratio, and can release them independently from each other in cancer cells via different triggering mechanisms. The significance of this breakthrough lies in the fact the patients would not need to be taking cocktails of different drugs that are often added in different packages, but only one that contains all the necessary ingredients. 5) It is not science; nevertheless the realignments of businesses from large pharma companies can/will have significant impacts on their R&D activities. As described in C&EN quite a few surprising things happened this month: 1) GSK selling its Oncology division to Novartis for up to $16 billion; 2) Novartis selling its Vaccine business to GSK for up to $7 billion (flu vaccine business excluded, and going to a separate buyer); 3) GSK and Novartis combining their Consumer Health businesses in a 63.5% and 36.5% ratio, respectively; 4) Novartis selling its Animal Health unit to Eli Lilly for $5.4 billion, that in combination with Lilly’s Elanco creates the world’s second largest such unit after Pfizer’s spin-off, Zoetis; and finally 5), according to UK’s Sunday Times, Pfizer made a $100 billion bid for acquiring AstraZeneca. That deal although was rejected, a second approach can be expected soon. ---------------------------------------------------------------------------------------------------------------- References 1) https://www.sciencemag.org/content/early/2014/04/02/science.1252268.abstract 2) http://pubs.acs.org/doi/abs/10.1021/ja5017156?source=cen 3) http://cen.acs.org/articles/92/web/2014/04/Mixing-Matching-Metals.html 4) http://www.nature.com/nmat/journal/v13/n5/full/nmat3911.html 5) http://pubs.acs.org/doi/abs/10.1021/ja502011g?source=cen 6) http://cen.acs.org/articles/92/web/2014/04/Pharma-Firms-Swap-Assets.html