A hybrid synthesis strategy enables complex molecular architectures to function as a single electronic system.
Scientists are getting closer to building materials one molecule at a time, a long-standing goal that could reshape electronics, energy systems, and sensing technologies. At the heart of this effort are flat, carbon-rich molecules known for their ability to move electrical charge efficiently. These structures already appear in devices like solar cells and chemical sensors, but researchers have been searching for ways to push their performance even further.
One promising idea is to connect multiple molecules into larger networks so they behave like a single, more powerful system. In theory, this extended structure can improve how electrons flow, which is critical for faster and more efficient devices. In practice, though, making these larger assemblies has been a major obstacle. As molecules grow, they often stop dissolving in liquids, which makes them difficult to synthesize using standard chemical techniques.
A Hybrid Strategy for Complex Architectures
A team led by Luis M. Mateo and Diego Peña at the Center for Research in Biological Chemistry and Molecular Materials (CiQUS) has developed a way around this problem using a hybrid approach. They begin by synthesizing carefully designed phthalocyanine units in solution. These units are then placed onto a metal surface, where they react and join together to form an extended structure made of five cross-shaped, fused phthalocyanines.
This method brings together the control of traditional solution chemistry with the advantages of surface-based reactions carried out under controlled conditions, enabling the creation of structures that were previously difficult to achieve.
“The surface not only facilitated the synthesis of the phthalocyanine pentamer but also enabled its sub-molecular resolution characterization using scanning probe microscopy,” says CiQUS researcher Luis M. Mateo.
Electronic Properties and Functional Potential
The resulting structure forms a nanoscale system in which all five units behave as a single electronic entity. Experiments show that linking the units lowers the energy gap, an important factor for charge transport and the performance of advanced materials.
The design also takes advantage of the ability of phthalocyanines to bind metals within their central cavity. This makes it possible to place different metals at specific points in the structure, introducing new properties such as magnetism in the central region.
Diego Peña explains that the next step is to “modify the molecular precursor design to access two-dimensional polymers formed by phthalocyanines, a nanomaterial that will allow us to explore unique properties.”
This research, carried out as part of the MolDAM project (ERC Synergy Grant), involved close collaboration with the University of Regensburg (Germany) and IBM Research Europe–Zurich (Switzerland). By combining advanced chemical synthesis with atomic-resolution microscopy, the team has opened new possibilities for building complex molecular systems.
The findings could support the development of next-generation materials for molecular electronics, quantum technologies, and energy applications.
Reference: “Combined In-Solution and On-Surface Synthesis of a Fully Fused Cross-Shaped Phthalocyanine Pentamer” by Luis M. Mateo, Tzu-Chao Hung, Andreas Rank, Raffael Spachtholz, Felix Giselbrecht, Jonas Schön, Leo Gross, Jascha Repp and Diego Peña, 18 December 2025, Angewandte Chemie International Edition.
DOI: 10.1002/anie.202521922
CiQUS holds the CIGUS accreditation from the Galician Government (Xunta de Galicia), which recognizes the quality and impact of its research. It also receives financial support from the European Union through the Galicia FEDER 2021-2027 Program.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.