Celebrating 10 years of Chemical Science: Demonstrating new ideas and concepts

How have you managed to keep your research group motivated during the pandemic?

In Japan, we actually didn’t have a serious long-term lockdown, so we were able to work in the lab but with limited members in two groups. We were therefore able to maintain a sufficient level of research, so that was good. I worked from home mostly, and we used Slack to communicate as a group. Through this channel, members of the group were able to share some of their skills for others to learn from. Some members are experienced in coding, other members are experienced in the use of graphics software, and others are able to share their skills in carrying out DFT calculations. Each Slack channel was used as a learning tool – tutorials were given to help other members learn a new skill, and this provided an opportunity for questions to be asked on each topic. This was completely spontaneous, but we were all able to learn a lot from this.

We also used this time to connect with other groups from around the world. It was a great opportunity to discuss our science and exchange results, and is something that I’d like to continue to do in the future.  

What excites you most about your area of research and what has been the most exciting moment of your career so far?

I enjoy research that explores the structural transformations of assembled systems, and that demonstrates how systems can adapt to their environment and any external stimuli. Nature can do this because of evolution of course, with millions of years being spent adapting systems to a particular environment. For materials science researchers, it’s much more difficult.

I have several favourite papers that represent this kind of research. One of these, a paper published in Nature by Professor Matthew Rosseinsky, demonstrated the adaptable porosity of peptide-based metal organic frameworks (MOFs), which were able to form nine different conformations depending on the guest molecule. The authors used dihedral principle component analysis to correlate the movement of the dihedral angle of the peptide to the total structure in order to understand how the structure changed. This was such beautiful work.

Another paper that I would like to highlight, by Professor F. Akif Tezcan (Nature 2018), demonstrates something similar but on a macroscopic scale and based on protein crystals. In this work, the authors were able to use polymers to alter parts of a protein, which enabled them to tune the resulting crystals. Macroscopic expansion of the crystals was demonstrated, whilst maintaining the lateral positon. The vector is therefore the same, but the proximity changes. This work demonstrated such careful control from the molecular to the macroscopic scale.

Becoming a group leader has led to some incredibly exciting moments in my career. On a few occasions, members of my group have come into my office with such a serious expression on their face when presenting data that wasn’t expected. They automatically assume that something has gone wrong during the experiment. However, most of these situations are actually quite exciting because unexpected data can come from completely different reactions to what we had expected. This allows us to construct a new story. Unexpected data means that we have to rethink our hypothesis, and through reconstruction, we can carry out new experiments to confirm our results and provide the correct answer. This has happened on a number of occasions, and I always find it incredibly exciting.  

What has been the most challenging moment of your career so far?

From 2007–2017, I was working as a group leader under the guidance of Professor Susumu Kitagawa, handling one of his sub-groups. In 2017 I became an independent professor, and my group was initially made up of only three members. We therefore had to be selective in which projects we wanted to pursue. That was quite a difficult moment, but I really appreciated the input of my postdoc at that time, Dr Gavin Craig. He was really helpful and worked incredibly hard, as he had to take over quite a lot of projects, and at the same time maintain his own research.

Your first publication with Chemical Science was back in 2015, and you have subsequently had one of your publications chosen as a Pick of the Week. What would you say has been the most important advance in your area of research over this time?

In our first paper in 2015, we demonstrated how we were able to prepare superstructures of flexible metal organic frameworks over multiple length scales. Here, not only were we able to control the molecular structure at the nanoscopic level, but we were also able to control the positioning of the crystals to make hierarchical architectures. From this work, we realised that there was potential to propagate the structure dynamics from the macroscopic to the nanoscopic level. However, we noted that this would be very difficult to do because of the crystallinity of MOFs – they become hard materials and can become brittle under mechanical stress.

We then switched to making porous materials with metal organic polyhedra, containing cage molecules, in order to prepare systems with more of a flexible nature, which led to a 2018 publication in Chemical Science that was chosen as a Pick of the Week. Our research in Chemical Science over the past five years therefore tells quite a nice story - by changing the metal material to a cage, we were able to show the first example of flexible metal organic polyhedra. In 2020, we are now working out how we can enable transpropagation of mechanical stress in these kinds of systems, which could lead to a number of interesting applications.

Which Chemical Science publication would you say you are most proud of and why?

We only publish papers in Chemical Science that present novel and interesting concepts, so I would definitely say that I am proud of them all! If I had to choose one however, it would be our contribution from 2019, which demonstrated the induction of gradients inside porous materials through the application of gravity. We were able to achieve this through a detailed understanding of the assembly process. I really like this concept because, through controlling the gradient, we had the chance to tune the chemical potential, which means that we can initiate the unidirectional transport of molecules. On the mesoscopic level, we are therefore able to the tune the properties of these systems.

I am very happy to say that all of my submissions to Chemical Science have been accepted. I think this is for two reasons: First of all, we only ever submit research that presents a new concept to the journal, but also because I think that Chemical Science is very accepting of new ideas and fundamental research. Other journals are quite picky, and I think care too much about research that will receive citations within the first two years rather than considering the impact that research will have in the long-term. Chemical Science is very good at choosing conceptually novel papers that will really be ground-breaking in the field over the next five to ten years.

What goal would you set for yourself over the next 10 years?

My interests lie in translating the level of control that we have in normal macroscopic systems to the corresponding nanoscale systems. In order to do that, we require an understanding of the whole structure and all of the features of the system that we are investigating, from the nano- up to centimetre scale. I also want to further explore the introduction of separate components into these kinds of systems - if we can include more components, we have an opportunity to optimise the properties further