The GDCh in Jena and the CRC234 "CataLight" jointly invite Gary Hanan to talk about his research on "Thermal- and Photo- Assembly of Discrete Metallocycles as Light-Harvesting Complexes"Self-assembly is a powerful synthetic tool that has led to the development of one-, two- and three-dimensional architectures [1]. From Metal Organic Frameworks to molecular flasks, self-assembled materials have proven to be of great interest to the scientific community. This presentation will highlight our recent advances in the construction and de-construction of supramolecular structures through thermal- and light-induced self-assembly and dis-assembly. More specifically, the combination of two approaches, a [4 x 1]-directional bonding strategy [2] and ligand photo-dissociation [3], allows the self-assembly of a polypyridyl Re(I) and Ru(II) precursors into a discrete molecular triangles and squares. Diffusion-ordered NMR spectroscopy confirmed the synthesis of a higher volume species, while the identity of the species was established by high-resolution mass spectrometry and single-crystal X-ray diffraction studies (Figure). The light-harvesting ability of these complexes is examined, for example, the tetraruthenium square has a quantum yield three orders of magnitude higher than its mononuclear precursor and a prolonged excited-state lifetime. The results indicate that self-assembly is obtained not only by classic thermal techniques but by simple light-irradiation as well [4]. This approach can also be applied to a new class of ligands, AMidine-N-Oxides (AMOXs), which are strong pi-donors and lead to metallomacrocycles and metallopolymers with interesting photoactivity, including Aggregation Induces Emission (AIE) [5]. References 1. T. R. Cook, P. J. Stang, Chem. Rev., 2015, 115, 7001.2. B. J. Holliday, C. A. Mirkin Angew. Chem. Int. Ed. 2001, 40, 2022.3. B. Durham, J. L. Walsh, C. L. Carter, T. J. Meyer Inorg. Chem. 1980, 19, 860.4. B. Laramée-Milette, F. Puntoriero, F. Nastasi, S. Campagna, G. S. Hanan Chem. Eur. J., 2017 23,16497.5. M. Lepage, J. Castro, G. S. Hanan, M. Cibian, Dalton Trans., 2026, 55, 10833.Garry Hanan is professor in the Department of Chemistry at the Université de Montréal, where he leads the Green Energy Group and is a member of the Centre for Green Chemistry and Catalysis. He earned his B. Sc. from the University of Winnipeg, Canada, his PhD from Université Louis Pasteur in Strasbourg, France, under the supervision of Jean‑Marie Lehn and subsequently conducted postdoctoral studies in Germany with Manfred T. Reetz and in Italy with Vincenzo Balzani and Sebastiano Campagna. Professor Hanan started his independent career at the University of Waterloo (Canada) and moved to the Université de Montréal in 2002. His research focuses on the design and synthesis of supramolecular photocatalysts capable of harvesting solar energy to drive chemical transformations, most notably the photoproduction of fuels via water-splitting (producing H₂) and CO₂ reduction. He has received numerous distinctions, including awards from IUPAC and NSERC, highlighting his contributions to sustainable chemistry and molecular materials science. He also actively promotes international student exchange.