Wiengarten A.Lloyd J.A.Seufert K.Reichert J.Auwärter W.Han R.Duncan D.A.2023-06-162023-06-1620150947-65391521-3765https://doi.org/10.1002/chem.201502001https://hdl.handle.net/20.500.14365/3348Selectivity in chemical reactions is a major objective in industrial processes to minimize spurious byproducts and to save scarce resources. In homogeneous catalysis the most important factor which determines selectivity is structural symmetry. However, a transfer of the symmetry concept to heterogeneous catalysis still requires a detailed comprehension of the underlying processes. Here, we investigate a ring-closing reaction in surface-confined meso-substituted porphyrin molecules by scanning tunneling microscopy, temperature-programmed desorption, and computational modeling. The identification of reaction intermediates enables us to analyze the reaction pathway and to conclude that the symmetry of the porphyrin core is of pivotal importance regarding product yields. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.eninfo:eu-repo/semantics/closedAccessheterogeneous catalysisporphyrinsring-closing reactionselectivitysymmetryByproductsCatalysisCatalyst selectivityCrystal symmetryDehydrogenationPorphyrinsReaction intermediatesScanning tunneling microscopyTemperature programmed desorptionComputational modelCyclodehydrogenationHomogeneous catalysisIndustrial processsPorphyrin moleculesReaction pathwaysRing-closing reactionsStructural symmetrySurface reactionsArticle10.1002/chem.2015020012-s2.0-84939467343