ChemComm Milestones – Hennie Valkenier

Our ChemComm Milestones campaign aims to highlight authors who have published their first independent research article in our journal. We were excited to speak to Hennie Valkenier about her experiences as an emerging author and her #ChemComm1st article: Transmembrane transport of copper(i) by imidazole-functionalised calix[4]arenes.

Read our interview with Hennie here:

What are the main areas of research in your lab and what motivated you to take this direction?
Our main area of research is the development of synthetic transporters for ions and we have a particular interest in the transport of phosphate and phosphorylated compounds, for which I received an ERC starting grant (ORGANITRA). I have always been fascinated by the possibility that chemistry offers to design compounds for any purpose and to then actually synthesise and test these compounds. This process of molecular design, synthesis, and testing allows, firstly, to deepen our understanding of how these compounds function, and secondly, to develop new materials or applications. During my PhD, I worked on organic compounds for applications in molecular electronics. After my PhD, the many health challenges that our society faces and my interest in biological processes prompted me to reorient my research towards supramolecular chemistry. This allowed me to follow my passion to design, synthesise, and study compounds, now with the purpose of transporting ions through lipid bilayers. This research has many fundamental aspects, but also offers perspectives on medical purposes (Chem. Sci. 2019).

Can you set this article in a wider context?
The research efforts on ion transport by synthetic compounds have increased rapidly over the past 20 years. The vast majority of this work focusses on only a limited number of ions (such as Na+, K+, and Cl), for which the methodology to study the transport process has been well established. The transport of these anions is indeed very important in biology, for instance in signal transduction and homeostasis. However, the transport of other ions, including phosphates and Cu+, also plays a crucial role in biology, while little or no research has been done to try and mimic these processes with synthetic systems. The challenge is that this requires not only the development of compounds that could bind and potentially transport these ions, but also the methodology to study the transport process. Nathan Renier is the first student who had the courage to start a PhD under my supervision and in this ChemComm article we show that it is indeed possible to transport Cu+ through lipid bilayers with synthetic compounds and to monitor this process by fluorescence spectroscopy. These results encouraged us to start exploring the biological effects of Cu+ transporters.

What do you hope your lab can achieve in the coming year?
First of all, I hope that the different team members can continue to grow as researchers and enjoy discoveries (whatever their scale) and hard work paying off. We also hope to find new synthetic transporters, deepen our understanding of transport processes, and transport challenging ions such as phosphates. And with Nathan and various collaborators we hope to demonstrate that we can transport Cu+ into cells.

Describe your journey to becoming an independent researcher.
I am firstly grateful to all my supervisors for their continuous support combined with the freedom to develop my research projects, to try new things, and pursue ideas even if only some of them turned out well. In Groningen, Kees Hummelen allowed me to reorient my research project and set up collaborations with specialists in the field, to work at the forefront of molecular electronics. In Bristol, Tony Davis has introduced me to the field of supramolecular chemistry and ion transport during the 3 years I worked with him as a postdoc. In his group, I also had the privilege to work with several PhD students, allowing me to gain experience in supervision. Through the “Supramolecular Chemistry in Water” COST network, I met with Kristin Bartik and Gilles Bruylants from Brussels (ULB), whose “Engineering of Molecular NanoSystems” laboratory I joined to look at anion binding and transport from a rather different perspective. They also taught me and supported me in the writing of grant proposals, starting with small grants for equipment, to later arrive at the grant for my permanent research position with the national research council FNRS and an ERC starting grant, which launched my career effectively.

What is the best piece of advice you have ever been given?
When thinking about grant proposals, my colleagues at the ULB told be to dream big. It feels safer to propose a project that is close to what is known to work, but aiming for something that we can currently only dream about is worth the risk. Another very good piece of advice, from Tony Davis, concerns publishing results: Tell a story. Research data is indispensable, but rationalising the trends observed and drawing conclusions that are more general and teach lessons that are also applicable to the research projects of other people is a lot more interesting.

Why did you choose to publish in ChemComm?
ChemComm reaches a very broad audience, which is a great platform for our interdisciplinary research. Furthermore, the clear and concise format of ChemComm is highly suitable for a proof-of-concept article. I also had good experiences with the RSC, in their fair and professional handling of manuscripts. Thus, we were delighted to see Nathan’s first article on Cu+ transport published in ChemComm.

Hennie Valkenier studied Chemistry at the University of Groningen and obtained her PhD from this university in 2011 with a thesis on Molecular Electronics, supervised by Prof. Kees Hummelen. After a year of teaching in West-Africa, she joined the group of Prof. Tony Davis at the University of Bristol as a post-doc to develop transmembrane transporters for chloride. In 2015, she moved to the Université libre de Bruxelles (ULB) to work as a post-doc with Profs. Kristin Bartik and Gilles Bruylants in the Engineering of Molecular NanoSystems laboratory, where she obtained a permanent position as FNRS Research Associate in 2018. Her research efforts focus on the development of receptors for the transmembrane transport of ions.

Find Hennie’s work, and other #ChemComm1st articles, in ChemComm Milestones – First Independent Articles.

Find out more on our Twitter #ChemCommMilestones #ChemComm1st.

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Breaking the rules of valency for silicon and germanium

As every chemist knows, carbon likes to play by the rules and is almost always tetrahedral and tetracoordinate. There are exceptions to this geometry though; examples of planar tetra-, penta- and hexacoordinate carbons have been experimentally detected or theoretically predicted. The other group 14 elements also behave similarly to carbon, but again, planar tetracoordinate (pt) or planar hexacoordinate (ph) silicon or germanium atoms have been reported as exceptions to the tetrahedral, tetracoordinate standard.

Planar pentacoordinate (pp) silicon (ppSi) atoms are desirable in 2D materials, and researchers in China and Mexico have now reported the first examples of planar pentacoordinate silicon and germanium atoms (ppX, where X = Si, Ge). The researchers used a ‘π-localisation’ approach in their design, where the formation of multiple bonds between the surrounding ‘ligand’ atoms and the Si or Ge centre led to viable ppX atoms in XMg4Y (X = Si, Ge; Y = In, Tl) or SiMg3In2 structures (Figure 1).

Structures of the two planar pentacoordinate Si/Ge species investigated. Pentagonal shapes, with 5 surrounding atoms coloured green for Mg or purple for In/Tl, with a central brown atom for Si/Ge, connected to each periphery atom.

Figure 1: Structures for the global minima of the two planar pentacoordinate Si/Ge structures

Based on the precedence of B or Al atoms as ligands for stabilising planar hypercoordinate carbon atoms, the researchers first investigated alkaline earth atoms to stabilise the group 14 centres, looking at XM52- structures (X = Si, Ge; M = Mg, Ca, Be). A local energy minimum and a planar, pentacoordinate D5h geometry was only calculated for the triplet-state magnesium species (Figure 2), indicating that analogues of XMg52- were suitable for further investigation.

The three possible lowest energy structures for XM5(2-). The left structure is pentagonal, with a central Si/Ge connected to each periphery atom. The middle structure shows the Si/Ge connected to 4 M atoms in a square shape, with the fifth M atom bridging above the top two M atoms in the square. The third structure on the right shows the Si/Ge atom connected to the 5 M atoms around it, but in an irregular, non-pentagonal shape, where the M atoms do not all connect outside the central Si/Ge atom.

Figure 2: Structures of XM52- (X = Si, Ge; M = Mg, Ca, Be), where Nimag refers to the numbers of imaginary frequencies [3A1 refers to the triplet state, 1A1 refers to the singlet state]

The researchers calculated the potential energy surfaces of both the singlet and triplet states of XMg52-, optimising the lowest-lying structures. They found that the most energetically favourable isomers of both SiMg52- and GeMg52- were planar tetracoordinate in the singlet state, but there was only a very small energy range (0.4-1.5 kcal mol-1) between these singlet ptX structures and the desirable ppX structure in the triplet state. The researchers therefore turned to substitution of one of the surrounding ‘ligand’ atoms for heavier group 13 elements, to build a suitable-sized cavity for planar pentacoordinate silicon or germanium. They investigated XMg4Y structures (Y = Al-Tl) and found that a planar pentacoordinate structure was the lowest in energy for Y = In or Tl, with a more substantial jump to the next highest energy level structure (2.4-3.9 kcal mol-1). They also investigated disubstituted systems, XMg3Y2, noting that only SiMg3In2 had a ppX structure at the global energy minimum. They also found that the ppXs investigated all had 16 valence electrons, defying the 18-electron rule standard.

Overall, the researchers have theoretically predicted the first examples of thermodynamically and kinetically stable planar pentacoordinate silicon or germanium atoms. These structures combine both stabilising magnesium and larger group 13 element ‘ligands’, and are suitable candidates for future experimental detection, proving that silicon and germanium can too, break the rules of valency and tetrahedral coordination.

 

To find out more, please read:

Planar pentacoordinate silicon and germanium atoms

Meng-hui Wang, Xue Dong, Zhong-hua Cui, Mesías Orozco-Ic, Yi-hong Ding, Jorge Barroso* and Gabriel Merino

Chem. Commun., 2020, 56, 13772-13775

 

About the blogger:

Photograph of the author, Samantha AppsDr. Samantha Apps recently finished her post as a Postdoctoral Research Associate in the Lu Lab at the University of Minnesota, USA, and obtained her PhD in 2019 from Imperial College London, UK. She has spent the last few years, both in her PhD and postdoc, researching synthetic nitrogen fixation and transition metal complexes that can activate and functionalise dinitrogen. Outside of the lab, you’ll likely find her baking at home, where her years of synthetic lab training has sparked a passion in kitchen chemistry too.

 

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ChemComm Milestones – Hiroaki Iguchi

We’re pleased to announce that Hiroaki Iguchi reached a ChemComm Milestone this year when he published his first independent research article in our journal. Check out Hiroaki’s #ChemComm1st article: ‘Emergence of electrical conductivity in a flexible coordination polymer by using chemical reduction‘. This Communication also features in our new themed collection on Functional Coordination Networks.

 

Find out about Hiroaki’s experiences as a first-time author in our interview below.

What are the main areas of research in your lab and what motivated you to take this direction?
The main direction of our research is to synthesize new solid-state materials with low-dimensional electron systems and to control their electronic states by external stimuli. So far, the discoveries of new electronic states have developed new materials such as high-temperature superconductors, quantum spin liquids and topological insulators. Since various electronic states can be stabilized in the materials with 1D and 2D electron systems, they are promising platforms for exploring new electronic properties. Recently, we are investigating molecular crystals with low-dimensional electron systems such as porous molecular conductors (PMCs), whose electronic properties can be controlled by molecular desorption/adsorption as the “chemical” external stimuli.

Can you set this article in a wider context?
Postsynthetic carrier doping is the essential technique to prepare electron-conductive pi-conjugated polymers. Some voids among the loosely packed polymer chains accommodate dopant molecules or ions, yielding the carrier doping. In contrast, the postsynthetic carrier doping in the densely packed molecular crystals is difficult due to the lack of voids. In this work, we found that the introduction of flexible ethylene moieties in the coordination polymer (CP) backbone enabled the postsynthetic carrier doping even in the densely packed molecular crystal. The flexibility played an important role in both forming π-stacked columnar structure (conduction pathway) and transforming the crystal structure under the redox reaction. Moreover, this work also indicates that the chemical doping in flexible CPs can be alternative way to prepare conductive CPs with rare through-space conduction pathway.

What do you hope your lab can achieve in the coming year?
Recently, we are actively studying porous molecular conductors (PMCs), which are new conductive porous materials sharing features of both metal-organic frameworks (MOFs) and molecular conductors. The research is still in the early stage, and we are working hard to establish the methodology for syntheses and guest-induced functional switching of PMCs. I hope we can report more PMCs and their fundamental physical properties in the coming year.

Describe your journey to becoming an independent researcher.
When I studied MMX-type chain complexes in my PhD course, my supervisor, Prof. Masahiro Yamashita told me, “Why are you still dealing with classic research? You have to challenge something new.” Then I became serious about creating new ideas for preparing novel organic-inorganic hybrid materials. Although all of them did not give results that I expected, I enjoyed my research life with a high degree of freedom. At that time, I found a new conductive molecular crystal containing naphthalenediimide (NDI) moiety, and hence I felt that NDI can be used as a conductive block molecule. After I became assistant professor in Prof. Masahiro Yamashita’s group, Masahiro gave me a chance to develop this idea. After his retirement in this March, I have managed my subgroup and actively studied conductive CPs with NDI or other π-conjugated moieties.

What is the best piece of advice you have ever been given?
My previous boss, Masahiro, was often asked, “What is science?” His answer was “Science is to create new scientific fields. Science should be not No.1 but only one.” Although I am still considering my answer, I will try my best to propose some new research concepts in the sea of science.

Why did you choose to publish in ChemComm?
I think that ChemComm is one of the world’s leading journals in the field of general chemistry. At the time I was thinking of preparing work for ChemComm, I received an invitation to submit a paper for a themed collection on “Functional Coordination Networks.” It was so timely that I decided to prepare and submit a manuscript.


Hiroaki Iguchi received B.S.(2006), M.S.(2008) and PhD(2011) in Chemistry from Tohoku University under the supervision of Prof. Masahiro Yamashita. Hiroaki’s thesis work focused on controlling electronic states of 1D halogen-bridged dinuclear metal complexes (MMX chains). In the PhD course, he also studied solid-state electrochemistry of MMX chains as a visiting student in Prof. Alan M. Bond’s group at Monash University, Australia. In 2011, he joined Prof. Nobuo Kimizuka’s group at Kyushu University, Japan, as the SPD Research Fellow of the Japan Society for the Promotion of Science (JSPS). Then, he was appointed as an Assistant Professor in Prof. Masahiro Yamashita’s group at Tohoku University in 2013 and started the research on conductive 1D halogen-bridged mononuclear metal complexes (MX chains) and porous molecular conductors (PMCs). Follow Hiroaki’s on Twitter: @HiroakiIGUCHI1

We hope you enjoyed learning about Hiroaki’s experiences becoming an independent researcher and some of the background to his research. Find Hiroaki’s Communication in our collection ChemComm Milestones – First Independent Articles and follow the hashtags #ChemComm1st and #ChemCommMilestones for more on our Twitter.

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ChemComm Milestones – Tom Hasell

We’re excited to bring you our interview with Tom Hasell who published his #ChemComm1st article in 2016. We spoke to Tom about his experience as a first-time independent author publishing ‘Porous inverse vulcanised polymers for mercury capture

Read the interview here.

What are the main areas of research in your lab and how has your research progressed since publishing your first article?
I’ve always worked in materials chemistry. I love investigating new materials and trying to understand how they work. But as well as just academic interest, I like materials that could have practical applications. Often one of the challenges for new academic materials is that they can be expensive to produce – either because of the cost of the starting materials, or the complex processes used to make them. That can be a real barrier to industrial applications. When I started my own group, I knew I wanted us to work on interesting new materials, but I wanted us to limit ourselves to ones that were cheap and ideally sustainable, so that they would have potential for widespread use. Trying to make functional polymers out of elemental sulfur is a great example of that ambition. Sulfur is a by-product of the petrochemicals industry, and the supply outweighs demand, so you can buy it for roughly transport costs. I’d seen some early papers showing that sulfur could be made into stable polymers – which we could maybe make useful materials from. Mercury has a high affinity for binding to sulfur, so these polymers could be great filters to capture toxic mercury – if they could be made porous. The paper we published as a new group, in Chemical Communications, was the first report of making these “inverse vulcanised” sulfur polymers porous, and showed that it improved their mercury uptake.
Since then we have carried on working in sulfur polymers, it’s a fascinating new area with a lot to explore, and since that paper we have gone on to explore other ways to induce porosity in these materials, such as by salt templating to make the porosity better connected, or by using carbonisation, or coating onto porous supports to generate microporosity. There are also a lot of non-porosity based applications for sulfur polymers that will depend on their physical properties, which we have been working to improve, as well exploring sustainable crosslinkers to react with the sulfur, and how catalysts can improve the synthesis. The unique nature of sulfur based polymers gives them potential for applications in optics, batteries, and as antimicrobial materials.

Describe your journey to becoming an independent researcher.
Some people are certain that they want an academic career from the start but I was never sure what I wanted to do after I finished university. In my fourth year as an undergraduate, I did a research project in Steve Howdle’s group and really enjoyed it. He asked me if I wanted to stay on and do a PhD and I agreed – I was enjoying the research and it would put off making a decision for a while. After the PhD, I continued in research working as a postdoc for Andy Cooper. I still wasn’t sure what I wanted to do but I was enjoying the research so I just kept on at it. I was nervous of going for an academic career because although I loved research, I wasn’t sure the struggle for funding, admin, and management were for me. After sitting on the fence for perhaps a little too long I decided to go for it anyway, and applied for a Royal Society fellowship, which is what gave me the independence to start my own group. In honesty, the precarious nature of many years of short term contracts, and lack of security was difficult, and at times it was a bumpy road that almost made me leave academia. I can see why it puts people off, and I think we need to change this.

What is the best piece of advice you have ever been given?
Learn the difference between urgent and important. It’s great advice. I’m terrible at it.

Why did you choose to publish your first article in ChemComm?
ChemComm was always one of my favourite journals as PhD student and postdoc. The short format means the key message of the research tends to come across clearly. As a new group, the broad readership and good reputation of the journal made it a great target for our first paper.

Tom Hasell is a Lecturer and Royal Society University Research Fellow in the Stephenson Institute for Renewable Energy at the University of Liverpool. Originally from Yorkshire, he is a graduate of the University of Nottingham, where he stayed to complete a PhD under the supervision of Steve Howdle (Chemistry) and Paul Brown (Engineering), while collaborating closely with Martyn Poliakof, as well as placements in America (Eric Beckman, University of Pittsburg) and Japan (Satoshi Yoda, NIAST). He then joined Andy Cooper’s group at the University of Liverpool in 2008, initially as a postdoctoral researcher and later as a research coordinator. During this time he played a significant role in the development of porous organic cages. After securing a Royal Society University Research Fellowship, Tom was able to start his own independent group in Liverpool in 2015. This group is focussed on using waste to make functional new materials. He has worked in a wide range of areas across materials science, including polymers, supercritical fluids, nanocomposites, and porous materials. Tom was awarded the European Young Chemist of the year award in 2014, and was named as a Journal of Materials Chemistry Emerging Investigator in 2017. Follow Tom on Twitter: @TomHasell

Read more #ChemComm1st articles in #ChemCommMilestones – First Independent Articles  and follow the hashtags on our Twitter page.

 

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ChemComm Emerging Investigator Lectureship 2021 – nominations now open!

Know an outstanding emerging scientist who deserves recognition? Nominate now for the 2021 ChemComm Emerging Investigator Lectureship

We are pleased to welcome nominations for the 2021 Emerging Investigator Lectureship for ChemComm.
All nominations must be received by 1st February 2021.

ChemComm Emerging Investigator Lectureship

  • Recognises emerging scientists in the early stages of their independent academic career.
  • Eligible nominees should have completed their PhD in 2013 or later. Appropriate consideration will be given to those who have taken a career break or followed a different study path.

Lectureship details

  • The award aims to recognise emerging scientists in the early stages of their independent academic career. The winner will be invited to present a lecture on their work, as well as receive £1500 and a certificate of recognition.
  • The recipient will be asked to contribute a review article for the journal.

How to nominate

  • Self-nomination is not permitted. Nominators must send the following to the editorial team via chemcomm-rsc@rsc.org by 1st February 2021.
  • Recommendation letter, including the name, contact details and website URL of the nominee.
  • A one-page CV for the nominee, including a summary of their education, dates of key career achievements, a list of up to five of their top independent publications, total numbers of publications and patents, and other indicators of esteem, together with evidence of career independence.
  • A copy of the candidate’s best publication to date (as judged by the nominator).
  • Two supporting letters of recommendation from two independent referees. These should not be someone from the same institution or the candidate’s post doc or PhD supervisor.
  • The nominator and independent referees should comment on the candidate’s presenting skills.

Incomplete nominations or those not adhering to the above requirements will not be considered, and nominees will not be contacted regarding any missing or incorrect documents.

Selection procedure

  • The editorial team will screen each nomination for eligibility and draw up a shortlist of candidates based on the nomination documents provided.
  • The recipient of the lectureship will then be selected and endorsed by a selection panel composed of members of the ChemComm Editorial Board. The winner will be announced in the summer of 2021.

NB: Please note that members of the selection panel from the ChemComm Editorial Board are not eligible to nominate, or provide references, for this lectureship.

For any queries, please contact the editorial team at chemcomm-rsc@rsc.org.

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ChemComm Milestones – Silvia Marchesan

In 2011, Silvia Marchesan published her first article as a corresponding author in our journal. We wanted to speak to Silvia about why she chose ChemComm as home for Tripeptide self-assembled hydrogels: unexpected twists of chirality.

Read our interview with Silvia here:

What are the main areas of research in your lab and what motivated you to take this direction?
Nature’s choice for homochirality (e.g., L-peptides) has stimulated our research, as we question it with heterochiral molecules. The scientific journey in this direction started from the design of simple and low-cost tripeptides to define self-assembly rules within chemical systems of biological relevance. We typically use 1 or 2 D-amino acids in D,L- tripeptides, and study small libraries with variations in stereochemistry or amino acid sequence. We recently established how chirality affects spatial conformation for assembly from the molecular, through the nano-, micro- and up to the macroscale. In this way, we can link macroscopic properties of the final systems back to the fine structural details of the building blocks. Our systems assemble in benign solvents, such as buffered water or acetonitrile, and design allows the fine-tuning of their lifetime and biodegradation rate. Applications vary, from biomimicry of natural structures to antimicrobial or bioadhesive soft matter (ChemComm 2020), to the bioinspired design of catalysts (ChemComm 2017), whereby function can be switched on/off with assembly/disassembly.

As Alice steps into Wonderland through the mirror, so we like to think that use of the mirror-image of natural L-amino acids enables entry into a supramolecular wonderland, whereby the building blocks are similar overall to their natural counterparts, but with a “magical twist” (indeed, often D-amino acids induce a kink in the backbone). We also like the challenge to combine different systems together at the boundary with nanotechnology: a branch of our research enjoys stimulating collaborations to attain hybrid or composite nanomaterials with carbon nanostructures for new applications in catalysis, biomaterials, biomarker detection, etc.

Can you set this article in a wider context?
The 2012 Communication set the first example whereby a simple substitution of an L-amino acid with its D-enantiomer in an unprotected (linear) peptide sequence dictated a dramatic change in self-assembly behavior, since the tripeptides with D-L-L stereoconfiguration formed nanostructured hydrogels at physiological conditions, while their homochiral analogues simply precipitated. Moreover, a simple change of order in the amino acid sequence allowed to achieve different nanomorphologies (i.e., twisted fibrils or nanotapes), giving scope for further investigations. It took some years to obtain funding for this research and gather the required resources to identify the rationale behind these observations, as well as to convince skeptics that this approach can indeed be extended to other examples, and can add function to the assemblies. Examples include catalysis (ChemComm 2017) or mimicry of biological structures, such as the extracellular matrix (ECM) to sustain cell culture (ChemComm 2016) or even to induce cell adhesion, with bioactive ECM-derived motifs (ChemComm 2020). The possibility to create a desired function with the assemblies is especially attractive to attain spatiotemporal control over reaction cascades, or to design therapeutics that are activated where and when needed.

What do you hope your lab can achieve in the coming year?
Funding! Our funded projects have ended and further resources are required to make the leap towards tailored applications. These systems have a great potential: research has identified thus far sequences with very interesting properties, such as the ability to inhibit pathological amyloid fibrillization, and to exert antimicrobial activity only when assembled. Manuscripts are in preparation, so… stay tuned! Full-atom molecular dynamics simulations have unveiled how the peptides dance as they assemble, and single-crystal XRD has provided mesmerising photographs of water-channels formed by simple sequences, and with varying diameter in the nanometer scale. Given the required resources, I am confident we can produce useful dynamic systems and perhaps even shed a new light on life’s choice for homochirality.

Describe your journey to becoming an independent researcher.
I fell in love with research at first sight, and the fire burns bright despite the rollercoaster of academic life. My journey was non-conventional, as I simply followed the passion for science that led me from Italy (M.Sc. on fullerenes under the supervision of Profs Prato and Da Ros) to the UK (to work with Dr Macmillan who shared my love for (glyco)protein engineering), Finland (where I joined the group of Prof Gahmberg on integrin biochemistry and protein-protein interactions), Australia (joint postdoc between CSIRO and Monash University to work with Prof Forsythe on nanostructured biomaterials) and then back to Italy. When I was at UCL, after work, I loved to stop by the Wellcome Exhibition Centre and the British Library to get inspired. It is there that I discovered the original drawings of Alice in Wonderland, and I am extremely grateful to my supervisors in Australia for allowing me to explore new research avenues in my “spare” time. I wrote many unsuccessful grants, and after submitting what I thought was going to be the last one (thinking of plan B, out of academia), I hit the jackpot with a starting package from the Italian Ministry of Research (MIUR) through the SIR scheme. That was a game-changer that created momentum, and talented postdocs from abroad were attracted to the team, joining forces to explore the exciting area of supramolecular chemistry.

What is the best piece of advice you have ever been given?
To be true to your dream, and commit to it 100%. Enthusiasm is contagious, and creates very positive dynamics in a team. My PhD supervisor offered plenty of quotes from Star Wars, which in turn I offer to my team now! There is also a mask of Darth Vader next to my desktop, to remind me of the urgent need to prompt and implement positive change, to create a better and more inclusive culture in science.

Why did you choose to publish in ChemComm?
During the PhD I had published one article in ChemComm as first author, and I was impressed by the rapid publication times, simple process, and above all, fair and constructive peer-review comments. The whole experience made me feel welcome and part of the scientific community, reflecting other interactions with the RSC and in the UK. ChemComm offered the perfect platform to publish our proof-of-concept and to sail it out into the wider chemistry community. It was an uplifting and totally unexpected surprise to be sitting on my desk Down Under and receive emails from the other side of the world, from colleagues, and from my PhD supervisor, with congratulations for the work. It is important for emerging PIs to receive support from the community– even a short email made a positive and lasting difference.

Marchesan’s Group in 2018, before the COVID-19 pandemic

Silvia moved to UK in 2004 to join Procter & Gamble for an R&D internship, just before taking on a PhD at The University of Edinburgh (UK). She enjoyed also the research environment at UCL (2005-2007), where her PhD supervisor, Dr. Derek Macmillan, had established a new lab. She then moved to the University of Helsinki (2008-2010) as Academy of Finland Fellow, and then to Melbourne as CRSS Fellow (2010-2012) in a joint scheme between Monash University and CSIRO (Australia’s national science agency). In 2015 she set up her independent lab at the University of Trieste (www.marchesanlab.com), and secured a tenure-track position that led her to Associate Professorship (2018) and Habilitation for a Full Professorship (2018). The research potential of heterochiral self-assembling peptides was recognized by Nature Index (2018) and Nature Chemistry (2019). Find the lab on Twitter: @MarchesanLab

Don’t forget to read Silvia’s #ChemComm1st article in our collection ChemComm Milestones – First Independent Articles. Find out more by following the hashtags #ChemComm1st and #ChemCommMilestones on our Twitter.

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ChemComm Milestones – Sudeshna Roy

Earlier in the year, Sudeshna Roy published her first independent research article in ChemComm. As part of our ongoing #ChemCommMilestones initiative, we wanted to speak to Sudeshna about her experiences becoming an independent researcher. Read Sudeshna’s #ChemComm1st article here: Regioselective synthesis of 4-fluoro-1,5-disubstituted-1,2,3-triazoles from synthetic surrogates of α-fluoroalkynes.

Here’s our interview with Sudeshna.

What are the main areas of research in your lab and how has your research progressed since publishing your first article?
The central theme of our lab revolves around small molecules. We contribute to developing new methods and strategies to access small molecules of biological and medicinal relevance and using them as tools to probe biological questions or in human diseases. Currently, we are pursuing seemingly two disparate programs that I envision merging into a drug-discovery platform. We have always been drawn to fluorination strategies and the impressive surge in fluorinated pharmaceuticals and agrochemicals. We identified that fluoroalkynes, which would be the simplest precursor as a gateway for new fluorinated motifs, are elusive and notorious for undergoing spontaneous cyclotrimerization reactions. A search for synthetic surrogates led us into the domain of fluorinated alkenes and their fascinating chemical reactivity portfolio, primarily due to the polarity inversion feature. On the other hand, we are deeply committed to addressing the ongoing global health crisis of antimicrobial resistance by developing new chemotherapeutic agents against new and existing bacterial targets to expand our armamentarium of antibacterials. We are currently pursuing a multi-disciplinary collaborative project to develop a new class of compounds with narrow-spectrum activity against Mycobacterium tuberculosis (Mtb), the causative agent for tuberculosis. Our ultimate merger will be using the hand-tailored fluorinated compound library, developed in our lab, for ligand-based screening using 19F NMR against antibacterial targets of interest to seek effective and new antibacterials.

Since our first publication in ChemComm, the ongoing efforts have generated an array of diverse heterocyclic compounds using fluorinated alkenes as a synthetic precursor. Concurrently, we have discovered a new class of compounds that we are very excited about. The parent compound of this family shows a narrow-spectrum anti-tuberculosis activity, and other analogues show broad-spectrum activity, including methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococci (VRE).

What do you hope your lab can achieve in the coming year?
Like everywhere else in the world, our research has been severely impacted by COVID-19. All the labs at the University of Mississippi School of Pharmacy were shut down, including ours, for almost two months. We became partially operational starting mid-May at a much-reduced capacity. Accepting the reality that this will remain for a while, in the coming year, we hope to publish more in the area of fluorinated heterocycles, expand our research directions in fragment-based screening to merge our efforts of antibacterial discovery and fluorine chemistry. We also hope to continue our multidisciplinary collaboration on the tuberculosis drug discovery front. We are excited about our recent discovery of a new class of compounds that specifically inhibit Mtb’s growth and survival. We observed broad-spectrum activity through different chemical modifications of the parent compound, including MRSA and VRE. We are investigating the mechanism of action (MoA) and the biomolecular target. The parent compound’s MoA is unknown, whereas interestingly, some analogs target a protein called, MraY, which is involved in bacterial cell wall synthesis. We are definitely looking forward to resuming travel next year and attend conferences.

Describe your journey to becoming an independent researcher.
I have always been interested in chemistry and pursued B.Sc in chemistry from St. Stephen’s College in India and an M.Sc. in organic chemistry from the University of Delhi in India. During my Ph.D., I worked on the total synthesis of tetrahydrofuran-containing natural products with an anti-cancer activity that sparked my interest in small molecules’ biological applications. Hence, I expanded my focus to a more applied field of medicinal chemistry and drug discovery during my postdoctoral tenure. At the University of Kansas, I was part of the NIH-funded Molecular Libraries Probe Production Centers Network (MLPCN) Specialized Chemistry Center, where I participated in several drug-discovery projects in therapeutic areas ranging from mitochondrial permeability transition pore (mtPTP), multiple sclerosis, Alzheimer’s disease, and cardiovascular disease, to name a few. At the UNC Eshelman School of Pharmacy, I gained experience in developing inhibitors of RNA-binding proteins Hu antigen R and Musashi-1 RNA-binding proteins that are overexpressed in breast and pancreatic cancers. Through these experiences, I realized one of my strengths is building a team and leading multidisciplinary collaborative projects. It gives me a tremendous opportunity and pleasure to learn something completely new that I have never done before and integrate those skill sets in drug discovery projects.

I had an interesting journey transitioning to the University of Mississippi as a tenure-track faculty, though. I had no clue I would end up being a PI. As I was nearing the end of my postdoc tenure, I was mainly focusing on applying for industrial jobs. Being an international student, I had limited options with my then visa situation. Even though I was open to different opportunities, I always thought academia was daunting. Constantly thinking about new ideas, securing grant funding, and running a lab leaves you with not much for anything else. Thankfully, I had a couple of great mentors who believed in me and encouraged me to pursue academia. So, I applied and got lucky! Now I know all the scientific pursuits could be rewarding, despite all the challenges. We can be smart and choose how much time to spend to enjoy other aspects of life. It’s a lot of fun working with students that are so driven and passionate. It motivates me to do better to help them in their journey!

What is the best piece of advice you have ever been given?
I have been fortunate to have great mentors in my journey so far and learned a great deal through my advisors, colleagues, and students! However, there are a few that need special recognition. I will attribute my scientific growth to my postdoc advisor Prof. Jeffrey Aubé and being part of the Aubé lab. Jeff has always given me honest opinions and useful advice on setting up a lab and what to expect as a new PI. A close friend of mine, Debajit Saha, who is now an Assistant Professor at Michigan State, always told me to pursue crazy ideas and not be afraid of failure or making mistakes. I have yet to follow my crazy ideas, but I have definitely learned a lot through failures and mistakes. One of the most useful life advice I got was from my therapist. She reminded me to enjoy all aspects of life, think positively no matter what, keep dreaming where and what you want to be in the future; it will get you closer. So, I am always dreaming. Fingers crossed!

Why did you choose to publish your first article in ChemComm?
For our work on the use of fluorinated alkenes as synthetic surrogates for fluoroalkynes to access fluorinated triazoles, we wanted to reach out to a broader audience encompassing all areas of chemistry, materials to chemical biology. We hope our method for preparing fluorinated triazoles will find use in the agrochemical and pharmaceutical industry and materials sciences. We envisioned ChemComm would be a great platform to feature our work!

Bio: Sudeshna obtained her Ph.D. from the University of Missouri-St. Louis. She then joined Professor Jeffrey Aubé’s group for a post-doctoral position first at the University of Kansas and then at the University of North Carolina at Chapel Hill. Sudeshna was appointed as an Assistant Professor of Medicinal Chemistry at the University of Mississippi School of Pharmacy in 2017. Her laboratory develops and applies small molecules for various therapeutic areas, mainly focusing on antibacterial drug discovery. Follow Sudeshna on Twitter: @Roy_Laboratory

 

You can find Sudeshna’s Communication, and other #ChemComm1st articles, in our collection ChemComm Milestones – First Independent Articles.

Or follow the hashtags on our Twitter for more interviews: #ChemCommMilestones #ChemComm1st

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Excited-state aromaticity for metal systems

Chemists use many rules to describe and predict molecular properties and behaviours. Hückel’s rule is a well-known example, and is used to determine the aromatic character of planar, cyclic molecules containing π-bonds. Aromaticity is the property that increases the stabilisation of a planar molecule by the delocalisation of electrons in π-bonds, and according to Hückel’s rule, a molecule is aromatic if it contains 4n + 2 π-electrons and antiaromatic if it contains 4n π-electrons. Whilst Hückel’s rule applies to the singlet ground state of a molecule (i.e. when all electrons are paired), Baird’s rule is used to establish aromaticity in the triplet state (i.e. two unpaired electrons), and is essentially the opposite; aromatic for 4n and antiaromatic for 4n + 2 π-electrons (Figure 1). Baird’s rule is useful for understanding the excited (triplet) state properties of molecules, but has so far been limited to describing organic species only.

Huckel and Baird aromaticity for metal species

Figure 1. An example of a Baird aromatic all-metal species (left), with orbitals that exhibit Baird aromaticity in the triplet state (right), and Hückel antiaromaticity in the singlet state (centre)

A collaborative effort by researchers in China, Spain and Poland have now demonstrated that Baird aromaticity can be translated to all-metal systems using a series of DFT experiments. The researchers selected derivatives of Al44-­, a planar moiety with 4 π-electrons that is antiaromatic in the ground state (consistent with Hückel’s rule). They determined that in the triplet (T1) state, the two unpaired electrons in Al44-­ occupied σ molecular orbitals (MOs) instead of π MOs; these are the singly-occupied molecular orbitals (SOMOs) shown in Figure 2 that show anti-bonding character for the σ-radial system. The researchers could then infer a triple aromaticity for the triplet state of Al44- from the formal electron count: Hückel aromaticity of the 2 electrons in the σ-tangential system (HOMO); Hückel aromaticity of the 2 electrons in the π-system; and Baird aromaticity of the 4 electrons in the σ-radial system (SOMO, SOMO’ and HOMO-2).

Molecular orbitals for Al4(4-)

Figure 2. The key molecular orbitals and optimised structure for the triplet state

To further confirm the Baird aromaticity of the triplet Al44-­, the researchers calculated the singlet-triplet energy gaps of both the naked anion and the cation stabilised species, Li3Al4. They noted small energy gaps between the singlet and triplet states, which most likely results from the extra stabilisation of the Baird aromaticity in the triplet state. The researchers also performed an electron density of delocalised bonds (EDDB) analysis to quantify the extent of electron delocalisation (and therefore aromatic character) of Al44-­, Li3Al4 and other metallic systems, in comparison to a classical Baird aromatic organic molecule, cyclobutadiene (CBD). They noted comparable values for π-electron delocalisation in the metallic systems compared to CBD, indicating triplet state aromaticity. Additional calculations carried out by the researchers further proved the Baird aromatic character of the all-metal systems, demonstrating how the concept of Baird aromaticity can be extended beyond organic systems and paving the way for future understanding of aromatic, excited state metallic systems.

 

To find out more, please read:

All-metal Baird aromaticity

Dandan Chen, Dariusz W. Szczepanik, Jun Zhu and Miquel Solà

Chem. Commun., 2020, 56, 12522-12525

 

About the blogger:

Dr. Samantha Apps just finished her post as a Postdoctoral Research Associate in the Lu Lab at the University of Minnesota, USA, and obtained her PhD in 2019 from Imperial College London, UK. She has spent the last few years, both in her PhD and postdoc, researching synthetic nitrogen fixation and transition metal complexes that can activate and functionalise dinitrogen. Outside of the lab, you’ll likely find her baking at home, where her years of synthetic lab training has sparked a passion in kitchen chemistry too.

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ChemComm Milestones – Marta Figueiredo

Marta Figuerido reached her first ChemComm Milestone with this article: Electrocatalytic synthesis of organic carbonates. We spoke to Marta to find out about her experiences as a first-time independent author and why she chose to publish with ChemComm. Read our interview with Marta below.

 

What are the main areas of research in your lab and what motivated you to take this direction?
My main areas of research are electrochemistry and electrocatalysis for energy storage and conversion and synthesis of high-value chemicals. This research is highly motivated by the urgent need for new energetical solutions, either new energy systems or systems based on renewable energy sources. Electrochemistry has the unique possibility of making and breaking bonds by using renewable electrons. This offers the possibility to store energy in chemical bonds, such as in hydrogen and formic acid, to make renewable fuels (such as ethylene and ethanol) or even produce bulk chemicals (such as organic carbonates).

Can you set this article in a wider context?
With this article, we aim to reinforce, within the scientific community and/or chemistry enthusiasts, the idea that fundamental studies are of paramount importance towards the development of new technologies and solutions. It is required to understand the systems at the molecular and nanoscale level in order to optimize it. The investigations reported in this article, do not provide a solution for the synthesis of organic carbonates yet, however, they are a stepping stone for the development of this alternative process.

What do you hope your lab can achieve in the coming year?
Scientifically, I hope that our lab achieves recognition in the field of electrocatalysis for the synthesis of chemicals and gives significant contributions to the scientific community. We are still a young lab, but luckily, we are within the Inorganic Materials and Catalysis group. This group provides not only all the necessary experimental tools but also a broad range of expertise in heterogeneous catalysis, design of catalytic materials and computational modelling that will make our tasks much more comfortable. Moreover, I am surrounded by incredibly motivated researchers (PhD’s and postdocs, technicians and colleague staff members) that I am sure will help with this new goal. I sincerely hope that the world wins the fight with COVID and we can go back to our lab and enjoy science together.

Describe your journey to becoming independent researcher.
My journey to becoming an independent researcher was longer than what is assumed to be the norm. After my PhD, I was a postdoc in 3 different Universities in Europe (Finland, Netherlands, and Denmark). My postdocs were all in the field of electrochemistry, but only the last two were focused on electrosynthesis. Before my current position, as an Assistant Professor at TU/e, I worked as a researcher in industry. I consider that period as one of the most important of my scientific career. In addition to all the learning, it also contributed to develop and define my research aims and interests.

What is the best piece of advice you have ever been given?
Do what you feel its right, and everything else will be fine.

Why did you choose to publish in ChemComm?
There are two main reasons that made me choose to publish in ChemComm. Firstly, it was a personal milestone to publish at ChemComm. Secondly, I was aiming to publish this article in a journal of a broad audience and of general chemistry, and ChemComm is one of the most renowned journals with these characteristics.

Short bio: Marta Costa Figueiredo is Assistant Professor of Electrocatalysis at Eindhoven University of Technology since April 2019. She obtained her PhD in electrocatalysis, science and technology in 2012 at the University of Alicante, Spain under the supervision of Prof. Juan Feliu. After that, she was a postdoctoral researcher at different Universities in Europe such as Aalto University (Finland), Leiden University and University of Copenhagen. Before joining TU/e, Marta worked in the industry as Jr Scientist at Avantium (Amsterdam). In Eindhoven, her research is devoted to electrocatalysis and electro(catalytic)synthesis for sustainable processes and production of high value chemicals.

Find Marta on Twitter: @MartaCFigueired

 

All of our authors’ #ChemComm1st articles are now available in ChemComm Milestones – First Independent Articles.

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ChemComm Milestones – Alex Murray

This week, we are bringing you more from #ChemCommMilestones – we spoke to Alex Murray about becoming a first-time indepedent author and publishing with our journal.  Read Alex’s #ChemComm1st article: Ionicity-dependent proton-coupled electron transfer of supramolecular self-assembled electroactive heterocycles.

Find out more about Alex in our interview with him below.

What are the main areas of research in your lab and what motivated you to take this direction?
It’s probably easier to start with the second part: I trained as very much an organic chemist, but then moved to the US and learned electrochemistry as a postdoc, but I really am interested in redox-active small molecules more than anything else. The main applications that spring from this that we are researching are firstly new organic redox-flow batteries, and secondly the use of these small organic molecules as homogeneous electrocatalysts, especially with interesting interfacial behaviour.

Can you set this article in a wider context?
Well, this started as a side project really. I was watching a talk by a student from the Hiscock group in my first few weeks as a PI, and I was quite fascinated by their self-associating quinones. There has been so much fantastic and complex work done on the nuances of the electrochemistry of even quite simple quinones so I was really intrigued how these ‘quinone-SSAs’ would behave. What we found, broadly, is that the larger the size of the self-associated species, the more it behaved like a quinone in unbuffered or organic solution, so there appears to be some sort of barrier to proton transfer. But this is interesting, because for this system self-association makes the electron transfer faster, whereas often people have observed the opposite effect. I think with all the excitement about anthraquinones in organic redox flow batteries, the more unusual behaviours we know to look out for the better… and we are working on making other self-associated redox active heterocycles of course.

What do you hope your lab can achieve in the coming year?
Firstly we are following up on this collaboration, where we are interested in more complex supramolecular systems where we can control the self-association more readily. Secondly, we are hoping to make progress on both a new organic redox flow battery, and a new catalytic system we have in the works. It’s been a really tough few months, especially for my international PhD student who struggled to leave and return to her family, then struggled even harder to return to the UK. But things are looking up, and we are hoping to have more really exciting science to show within the next year.

Describe your journey to becoming independent researcher.
Since about a year into my PhD I think this is always something I’d wanted to do, though I was aware it’s not an easy road to say the least! I think the turning point for me was learning about electrochemistry – I really felt the confidence of having a more unique skill set than when I’d been trying to write ‘pure organic’ chemistry proposals, so my personal advice to PhD students and postdocs who want to be independent researchers is definitely to try and learn something very different – find a new field and learn to talk to them, but in a different way than how they talk to one other.

What is the best piece of advice you have ever been given?
“Why not, and what’s the worst that could happen”… this is good advice for crazy scientific ideas (the famous ‘Friday afternoon reaction’), but not in all aspects of life…

Why did you choose to publish in ChemComm?
We chose ChemComm because of the fast publication time, good support for early career researchers and positive previous experiences with the publication process at ChemComm and the RSC in general. Also this paper really sits at the interface of (organic) electrochemistry and supramolecular chemistry so it definitely made sense to go for a journal with a pretty general readership.


Alex was born in Hull, UK in 1989, and obtained an MChem in Chemistry from the University of Sheffield in 2011, with a year of this degree undertaken at Monash University (Australia). He then carried out research in redox organocatalysis at the University of Bath, working in the group of Dr. Dave Carbery, receiving a PhD in 2015. This also included a CASE placement at GlaxoSmithKline. Alex then moved to the University of Nottingham, working for one year in the group of Professor Chris Moody on generating sp3-rich scaffolds for medicinal chemistry. Alex then moved to the US, receiving a Dreyfus Postdoctoral Fellowship to work on electrochemical catalysis in the group of Prof. Yogesh Surendranath at MIT. In May 2018 Alex returned to the UK and was appointed as a Lecturer at the University of Kent.

Don’t miss more #ChemComm1st articles in our collection ChemComm Milestones – First Independent Articles.

 

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