Branco Weiss Fellowship Backs Radical Late-Stage Editing of Ultra-Stable Phthalocyanine Molecules

A fleeting molecular intermediate that survives for only a fraction of a second is at the heart of one of this year’s most closely watched early-career research awards. Luis M. Mateo, a postdoctoral researcher at the Centre for Research in Biological Chemistry and Molecular Materials (CiQUS) in Santiago de Compostela, Spain, has been named a Branco Weiss Fellow, one of the most selective international fellowships available to scientists in the early stages of an independent career. The five-year award, administered from ETH Zurich, will fund his attempt to do something that synthetic chemists have long considered close to impossible: selectively editing phthalocyanines, a family of extraordinarily stable molecules whose very robustness has made them notoriously resistant to modification once they have been assembled.

The Branco Weiss Fellowship, formally known as the Society in Science program, is designed precisely for ideas of this kind. It supports postdoctoral researchers from any discipline who want to pursue unconventional, potentially transformative research questions at the academic institution of their choice, and it accepts no more than ten new fellows each year. With funding of up to CHF 600,000, roughly €635,000, over five years, the fellowship gives its recipients an unusual degree of freedom at a career stage when most researchers are still working within the frameworks of their senior colleagues. Mateo becomes only the second Spanish researcher to receive the award and one of the first to carry out the fellowship in Spain, a milestone that highlights the growing visibility of Spanish molecular science on the international stage.

For Mateo, the award represents more than financial security. It provides the opportunity to begin building his own research team and to establish an independent research programme at the Universidade de Santiago de Compostela, where he has worked since 2021 as a postdoctoral researcher in the groups of Diego Peña and Dolores Pérez. In a statement accompanying the announcement, he described the fellowship as an exceptional opportunity to explore a high-risk idea with the freedom and time needed to develop it, noting that carrying out the project at CiQUS, an environment that brings together synthetic chemistry, nanoscience and molecular materials, would allow questions to be addressed that would be difficult to tackle from a single discipline.

The scientific problem at the core of his project, named PhthalocyanYnes, begins with a paradox familiar to anyone who works with functional materials. Phthalocyanines are among the most chemically robust molecules in modern chemistry. These large, flat, nitrogen-rich macrocycles have optical properties that made them commercially valuable as pigments decades before anyone spoke of molecular electronics, and today they are regarded as highly attractive building blocks for functional materials ranging from organic semiconductors to catalysts. Their celebrated stability, however, is a double-edged sword. Once a phthalocyanine has been synthesised, its structure is remarkably difficult to modify, which means that exploring new variants typically requires designing and building each target molecule from scratch, a laborious process that limits how quickly new materials can be discovered.

Mateo’s proposed solution is to weaponise instability against stability. The project aims to introduce an aryne, an extremely reactive molecular intermediate that exists for only a fraction of a second, into these highly stable molecular systems. Arynes are among the most energetic species a synthetic chemist can generate in a reaction flask; they are so short-lived that they are never isolated but instead captured in situ by nearby molecules. The central challenge of the PhthalocyanYnes project is to tame this fleeting reactivity and harness it to selectively transform the phthalocyanine framework, for example through cycloaddition reactions, in which the aryne forms new rings by adding across the stable molecular scaffold. If the strategy works, it would effectively turn the molecules’ greatest weakness, their inertness, into a design opportunity.

The payoff, if the chemistry can be controlled, would be a fundamentally new way of accessing families of phthalocyanine-based structures. Rather than synthesising each member of a molecular family individually, researchers could prepare a common advanced precursor and then diversify it at a late stage of synthesis, a philosophy that has transformed drug discovery in medicinal chemistry but remains largely unexplored for these pigment-derived materials. Late-stage functionalisation of phthalocyanines would make the molecules substantially more versatile and programmable, allowing optical and electronic properties to be tuned almost modularly, in the way that software engineers modify code rather than rebuilding a program from first principles.

To reach that goal, the project will combine several techniques that rarely converge in a single laboratory programme. Synthetic chemistry will provide the molecular scaffolds and the aryne chemistry needed to modify them. Advanced spectroscopy will be used to characterise the products and follow the reactions as they unfold. Computational modelling will help predict which aryne additions are feasible and what properties the resulting structures will have. Single-molecule characterisation, a specialty that has grown rapidly at CiQUS in recent years, will allow individual molecules to be imaged and probed directly, revealing whether the intended structures have actually been achieved at the atomic scale. Together, these approaches will be applied to molecular architectures that are currently difficult to access, including asymmetric phthalocyanine–carbon nanostructure hybrids, extended molecular networks and nanographenes with tunable optical, electronic and magnetic properties.

The potential applications extend well beyond the laboratory curiosity that such exotic molecules might otherwise remain. Phthalocyanines and their derivatives already play important roles in organic photovoltaics, organic light-emitting diodes, sensors and catalysis, and their rigid, planar geometry makes them natural candidates for molecular components in next-generation devices. The chemistry developed in the PhthalocyanYnes project could open new opportunities for the development of functional molecular materials for applications in optoelectronics and quantum technologies, fields in which the ability to fine-tune the electronic structure of individual molecules is becoming increasingly important. Molecular networks and nanographenes with precisely controlled shapes and electronic properties are also of intense interest for quantum information research, where the behaviour of single molecules and single spins can carry information in ways that conventional materials cannot.

Mateo’s path to this award reflects the kind of interdisciplinary training that such ambitious projects demand. He joined CiQUS in 2021 as a postdoctoral researcher within the ERC Synergy Grant MolDAM project, supervised by Diego Peña, and has since continued his research at the centre, developing expertise at the intersection of organic chemistry, molecular design, nanoscience, molecular materials and surface chemistry. That combination, spanning the design of new reactions, the study of molecules on surfaces and the construction of functional materials, is precisely the skill set needed to attempt late-stage aryne chemistry on scaffolds as demanding as phthalocyanines. His independent programme will strengthen CiQUS’s ability to attract and support emerging scientific talent and to pursue high-risk research with transformative potential, according to the centre.

CiQUS itself holds the María de Maeztu Unit of Excellence accreditation, one of the highest recognitions available to research centres in Spain, along with the CIGUS recognition awarded by the Xunta de Galicia, and it receives financial support from the European Union through the Galicia FEDER 2021–2027 Programme. For the wider European research community, the award of a Branco Weiss Fellowship to a researcher based in Spain, and the decision to develop the project there rather than relocating to a northern European hub, signals a shift in where unconventional early-career science can flourish. If Mateo’s fleeting arynes can indeed be captured and put to work on some of the most stable molecules known to chemistry, the result could be a new generation of programmable molecular materials whose properties are written into their structures one selective reaction at a time.

Subject of Research: Late-stage aryne-based modification of phthalocyanine molecules for programmable functional molecular materials

Article Title: Luis M. Mateo awarded Branco Weiss Fellowship to develop new approach to molecular design at CiQUS

Article References: Luis M. Mateo awarded Branco Weiss Fellowship to develop new approach to molecular design at CiQUS. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Branco Weiss Fellowship, Luis M. Mateo, CiQUS, phthalocyanines, aryne chemistry, late-stage functionalisation, molecular design, nanoscience, optoelectronics, quantum technologies, ETH Zurich, Universidade de Santiago de Compostela