Property-Enhanced Porphyrins

Lead Research Organisation: University of Sheffield
Department Name: Chemistry

Abstract

In natural photosynthesis, the sun light is directly collected and conveyed to a pair of precisely organised porphyrins, the special pair, which undergoes charge separation. The liberated electron is then translated into chemical energy that is used to develop the living organism. In brief, photosynthesis consumes carbon dioxide and water to produce energy-rich molecules and delivers Oxygen as a by-product. While the efficiency of natural photosynthesis is questionable, its molecular building blocks are self-assembled, made from common non-toxic elements and its waste and by-products are environmentally favourable. In relation to our most pressing environmental challenges and ever-increasing energy consumption, photosynthesis thus represents the perfect solution.

However, the complexity of the molecular architecture involved in photosynthesis renders it difficult to reproduce artificially. Nevertheless, it is possible to mimic specific aspects of photosynthesis and researchers have concentrated their efforts in the development of carbon capture, bio-fuel production, water splitting and photovoltaic solar cells. Each of these approaches to artificial photosynthesis includes an antenna system to harvest the sun light. Alike in natural photosynthesis, the role of the antenna in these artificial systems can be played by a porphyrin.

Within femto- to picoseconds after absorbing the incoming sun light energy, the porphyrin undergoes specific mechanisms. Of particular interest to this project, we will investigate the following mechanisms: internal conversion, inter-system crossing and direct charge separation. Each of these relaxation pathways dictates the overall device's conversion efficiency. It is therefore crucial to understand the factors that can enhance these specific pathways to develop more efficient devices.

We propose use the latest laser technology to investigate these mechanisms that are ultrafast by nature. More precisely, we will systematically study the effect of atom substitution, ring bending, and ring expansion in series of unique single-porphyrins that differs from one-another by a single constituent. Similarly, to investigate the effect of host electronegativity, we will investigate porphyrin-embedded complexes (called cytochromes) that differs from one another by the nature of their ligand, and thus electrostatic environment.

The outcome of this project is to generate a list of physical characteristics that enhance either internal conversion, inter-system crossing or charge separation. With such list in hand we would then be able to design improved porphyrins for specific applications.

Planned Impact

Fossil fuels has been driving the British national economy and international policies for the past century. Unfortunately, the environmental changes associated with the extensive consumption of fossil fuels have now become a threat to the international and national social and economic equilibrium as we know it today. Consequently, the adaptation of UK's industries to a more sustainable energy production will be the key factor for the country's competitiveness in the next decades. In the particular case of the UK, the EPSRC has been one of the major driver for this adaptation by investing in its Solar Technologies research area portfolio. Indeed, it is agreed that solar energy is the one sustainable energy source that, if harvested adequately, has the potential to respond to the ever-demanding energy needs of our society. This project, is directly aligned with EPSRC's effort in developing its Energy sector, and has the potential to impact the society at large.

Energy and environment are subjects that affect our daily lives. This project, because it aims at fostering the development of more efficient ways to generate renewable energy, will impact, in the mid- and long-term, all aspect of our lives, indiscriminately. If solar energy comes to liberate us from our oil dependences, as it is expected in the next decades, then this project would be an integral part of this transition.

Knowledge of a more efficient way to convert sunlight into chemical or electrical energy is a determinant step toward sustainable prosperity. An in-depth understanding and subsequent ability to control the relaxation pathways of photo-excited porphyrins will lead to the development of a cleaner energy production. This project thus comes right in time to foster technological innovations in renewable and sustainable energies.

The project's aims are also directly aligned with those of the Grantham Centre for Sustainable Futures; a joint project between the University of Sheffield and the Grantham Foundation. Through this collaboration, the output of the project will inform policy and the development of products for industrial application. Both of which will in turn affect the wider society by building fairer societies and preserve our natural resources for the future generations.

In economic terms, since the output of the project is to provide with a systematic approach in synthetizing porphyrins for specific applications, it will therefore participate in reducing the overall cost of research. For example, under better guidance, the research in the fields of Dye-Sensitized Solar Cell will be more effective. Consequently, this project will help maximizing the impact that governmental research funding has in a key investment area such as Solar Energy.

While in this section is only concerned with a summary of impacts, the pathways to achieve these impacts are detailed in the attached Pathway to Impact document.
 
Title Periodic Table of Poetry 
Description We supported an outreach project organised for the International Year of the Periodic Table. The goal is to create an interactive periodic table with a poem associated to every element. These poems are written by academic staff, student and pupils. It will be made available online hoping that it will promote a liking for the field of science (in particular, chemistry). This project fits within the grant as we are taking particular attention to the effect of specific element on the overall electronic dynamics of porphyrins. 
Type Of Art Creative Writing 
Year Produced 2019 
Impact The website is created but needs polishing. After completion, it will be made available online. 
 
Description We have monitored for the first time the electron dynamics of newly synthesised light-absorbing molecules.
This corresponds to the first step of the project. The goal being to understand how they behave, then to cross check all data and find trends to build a set of guidelines for the synthesis of purpose-build molecules.
(Jan 2020 update). We have completed the analysis of the first OEP-series. A manuscript is in preparation.
Exploitation Route Through publication and conferences first, then through direct contact with stakeholders.
Sectors Chemicals,Electronics,Energy,Pharmaceuticals and Medical Biotechnology

 
Description Indirectly, the findings have been used for outreach purposes.
First Year Of Impact 2019
Sector Education
Impact Types Cultural

 
Description EPSRC Capital Award for Core Equipment
Amount £549,334 (GBP)
Funding ID EP/T024526/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 02/2020 
End 08/2021
 
Description KE with Metallobio
Amount £4,500 (GBP)
Organisation University of Sheffield 
Sector Academic/University
Country United Kingdom
Start 09/2021 
End 01/2022
 
Title Long-time TA 
Description In partnership with Dr. Jenny Clark, the PDRA helped develop a transient absorption spectroscopy setup with time window spanning the ns-ms range. 
Type Of Material Improvements to research infrastructure 
Year Produced 2020 
Provided To Others? No  
Impact Publications are to come 
 
Description Christian Brückner: Sample provider 
Organisation University of Connecticut
Country United States 
Sector Academic/University 
PI Contribution We are characterising the ultrafast electron dynamics of the unique porphyrins that the collaborator has synthesised. He send us a couple of prophyrin series in 2016 and again in 2020. This collaboration was the basis of this grant. Hence, while it started before the grant was allocated, the grant enabled the collaboration to develop.
Collaborator Contribution Prof Bruckner has provided us with unique set of porphyrins.
Impact The first set of data are acquired and analysed. Publication is to come
Start Year 2016
 
Description Fyaz Ismail: antimalarial drug 
Organisation Liverpool John Moores University
Country United Kingdom 
Sector Academic/University 
PI Contribution We will provide with characterisation of the synthetized drug. The objective is to study it mode of operation, to possibly evaluate their efficiency.
Collaborator Contribution Provided with samples
Impact The first molecules have been characterised; data analysis is still to be finalized.
Start Year 2020
 
Description George Sutherland (Sample provider) 
Organisation University of Sheffield
Country United Kingdom 
Sector Academic/University 
PI Contribution We provided ultrafast and steady-state characterisation of the samples.
Collaborator Contribution The partner provided us with unique protein maquette for characterisation.
Impact Analysis of the data is still on-going.
Start Year 2020
 
Description Jacek Nycz: Proton transfer 
Organisation University of Silesia
Country Poland 
Sector Academic/University 
PI Contribution We are investigating the light induced proton transfers in the model proteins provided
Collaborator Contribution Provided with quinine-derivatives samples
Impact Frist sample received. Characterisation is to come
Start Year 2020
 
Description Jenny Clark: Tuning of the ISC 
Organisation University of Sheffield
Country United Kingdom 
Sector Academic/University 
PI Contribution Scientific contribution to develop a sub-project aimed at exploring the effect of host medium on porphyrin's inter-system crossing.
Collaborator Contribution Knowledge, expertise, access to equipment and further collaborators.
Impact Through this collaboration, we developed a long-time transient absorption (up to micro-second) to observe the more physiologically relevant processes.
Start Year 2019
 
Description Jim Thomas, Ru complexes 
Organisation University of Sheffield
Country United Kingdom 
Sector Academic/University 
PI Contribution Provided with photodynamic characterisations, looking at phototoxicity.
Collaborator Contribution Provided with Ru-complexes
Impact Hopefully, a publication will come out of the analysis.
Start Year 2021
 
Description Sami Rtimi: antibacterial thin film metal oxides 
Organisation Swiss Federal Institute of Technology in Lausanne (EPFL)
Country Switzerland 
Sector Public 
PI Contribution Provided with electron dynamic characterisation. While the collaboration started before this award, the award enabled the collaboration to develop further.
Collaborator Contribution Provided with samples
Impact One paper already published. And we have the data for two more publications.
Start Year 2015
 
Description Thiago Cardozo: Theoretical support 
Organisation Federal University of Rio de Janeiro
Department Institute of Chemistry
Country Brazil 
Sector Academic/University 
PI Contribution We have provided with steady-state and kinetic data on particular porphyrins.
Collaborator Contribution They have provided with modelling that will help interpret our data.
Impact A first set of porphyrins have been modelled; modelling it now to be refined based on the data we provided and publication is to come.
Start Year 2018
 
Description Viktor Nemykin, theoretical support 
Organisation University of Tennessee
Country United States 
Sector Academic/University 
PI Contribution Provide photodynamic characterisation.
Collaborator Contribution Provides DFT modelling of porphyrins.
Impact 1 publication, and another submitted manuscript. 1 more to come in 2022.
Start Year 2021
 
Description I'm a Scientist, Get me out of here! 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Outreach online platform where (registered) students can ask science-related questions.
Year(s) Of Engagement Activity 2020
URL https://imascientist.org.uk/
 
Description Invited seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited to give a seminar at the collaborator's research group, at Universidade Federal do Rio de Janeiro.
Year(s) Of Engagement Activity 2019
 
Description Postgraduate 1st year talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact This is a local event organised to give PhD students the opportunity to show their work to the wider student and staff within the university.
Year(s) Of Engagement Activity 2018
 
Description Postgraduate Poster Showcase 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact This is a local event organised to give PhD students the opportunity to showcase the group's research.
Year(s) Of Engagement Activity 2019
 
Description Tapton Secondary School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Outreach talk
Year(s) Of Engagement Activity 2021