Exploring colours in chemistry

16.07.2020

Colours have fascinated the organic chemist Davide Bonifazi since childhood. The newly appointed professor at the Faculty of Chemistry today works on creating new dyes, electrochromic materials and artificial light-harvesting antennas that pave the way for various innovative applications, ranging from new imprinted wearable devices to alternative ways of exploiting light in chemical transformations, such as the production of industrial fertilisers. His research is based on organic supramolecular chemistry.

"I have always been attracted to colours - not only in research, but also in private life," says Davide Bonifazi, deputy head of the Department of Organic Chemistry. "When you work with colours in the lab and you synthesise the molecules that turn a solution into a colour, it brings you close to the art of experimental science and observation."

In his research, Bonifazi focuses on using colours and creating new chromogenic and emissive materials for various applications. Efficient light-adsorbing architectures are one example. The molecules of a plant absorb the light (photons) in the visible range, and transform it into energy used to produce sugar or other nutrients. In the scientific field of energy harvesting, researchers aim to derive chemical energy from systems that mimic natural light-harvesting processes such as photosynthesis and to store this energy, e.g. in wireless and wearable electronics, while operating under a low-energy consumption regime.

  • From molecules to materials: In the field of organic supramolecular chemistry, researchers take advantage of the molecules' ability to self-assemble into bigger architectures, leading to an ultimate function. "But there is no simple narrative on how to get to these useful architectures. There are synergistic effects, among others, that impact the form of self-organisation," says Davide Bonifazi. "In synthesising and preparing molecules and bringing them together, we are trying to bridge the organic synthesis of molecules and complex matter in order to understand how to create and control complexity through the exploitation of exotic non-covalent interactions because final properties are founded on complex systems most of the time."

Electrochromic and optoelectronic devices

The development of self-organised organic semiconductors based on coloured molecules is a major research area of Davide Bonifazi. In two EU projects (DecoChrom and CHARISMA) with around 15 international partners, his research group currently develops and synthesises organic molecules and prototypes for flexible and printed electrochromic devices that could lead to innovations relating to sports, livestyle and health.

Imagine sneakers changing their colour when it is time for you to buy new shoes because you have already walked a certain number of kilometres. Or a wearable device that shows you when you need another insulin dose. "We are working towards this new, non-invasive form of communication in electronics by developing the devices, which change colour when you apply a chemical stimulus such as an oxidation or reduction," explains Davide Bonifazi.

The researcher synthesises the molecules for organic dyes and pigments for printed electronics and even develops first prototypes of lightweight printed wearables in his lab in collaboration with the relevant companies in the field. The organic synthesis of boron-nitrogen-doped polycyclic hydrocarbons and the use of chalcogen-bonding interactions to mould the structure of organic semiconductors are at the core of current investigations.

It is my dream to produce chemicals à la carte by only using solar light.

The future: the dream of a "solar cow"

Another area of Bonifazi's research is to chemically link solar light with the transformation of nitrogen into an exploitable form. This could provide alternative methods for the production of essential amino acids and proteins (as important constituents of food) as well as industrial fertilisers.

"I have a dream to create a solar cow in the lab that enables us to use solar light for transforming nitrogen into ammonia, for example. We would no longer need to produce fertilisers through the highly inefficient Haber-Bosch process as the main industrial procedure for fixing nitrogen and ammonia production." The solar cow would also be able to produce ammonia "that, if digested chemically or even biologically, could produce essential amino acids and peptides – as an alternative to eating mea," the researcher adds.

As the son of a farmer, Davide Bonifazi had often helped fertilise the family's land and had therefore started thinking about this topic early on. Instead of studying agricultural sciences, however, he went for chemistry: "I started searching for ways to turn my idea into reality only a few years ago. The most important challenge is to link the solar energy photo-chemically to the fixation of the nitrogen. Here, we are still facing a problem of energetics."

"Need to rethink the way we produce ammonia"

With his research group, Bonifazi is currently trying to optimise the absorption of solar light to such an extent that it can be used as an exploitable source for efficiently triggering photochemical reactions. Once this is accomplished, he expects to be able to couple the solar light harvester with a nitrogen fixation process: "We really need to rethink the way we produce ammonia, also considering the irreversible effects on the environment arising from the current nitrogen circle." The long-term objective is to integrate the whole photochemical process in a living organism, such as yeast, and create a biological synthesiser able to produce nutrients symbiotically. 


Univ.-Prof. Davide Bonifazi, PhD was appointed as professor of Organic Chemistry at the University of Vienna in April 2020. The former Chair Professor of Organic Supramolecular Chemistry of Cardiff University is interested in the creation of functional organic architectures through targeted organic synthesis, self-assembly and self-organization of organic architectures and material-/bio-based design. In 2011, he was awarded an ERC Starting Grant. Bonifazi studied at the University of Parma, Italy and conducted research at ETH Zurich, the Weizmann Institute, the University of Trieste and the University of Namur before he moved to the UK and Austria.

 

As one research area, Davide Bonifazi and his group try to derive chemical energy from systems mimicking natural light-harvesting systems (Copyright: Bonifazi research group).
Davide Bonifazi started his professorship at the University of Vienna in April (Copyright: Bonifazi research group).