This project of basic research in chemistry tackles the challenge to close the wide gap between chemical and physical processes occurring in liquid solution and sophisticated studies of model systems in the idealized gas phase. By such the project aims to reach a convergence between the microscopic and macroscopic world. To this end, the planned research will span the range from isolated atoms in the high vacuum to the real species present in solution. Specifically, the proposal is focused on:- Ion solvation in dipolar media (e.g. aqueous salt solutions)- Influence of sequential solvation on redox processes (relevant in corrosion, for example)- Mechanisms by which metal catalysts facilitate chemical reactions (e.g. polymerizations)In order to address these tasks, the PI will combine his profound expertise in gas-phase methods with well-established techniques from solution chemistry for the development of new and innovative coupling techniques which will allow to derive direct correlations between micro- and macroscopic properties. A particular highlight is the planned online-coupling of electron paramagnetic resonance (EPR) with electrospray ionization (ESI) mass spectrometry, which is unique worldwide and offers the exploration of new dimensions for both, EPR methods and ESI mass spectrometry.While the project is located in chemical sciences, physical-organic chemistry in particular, the prospects of the proposal range not only far beyond the PI's specific field of specialization into other areas of chemistry, but due to the enormous relevance of ion solvation, redox processes, and catalysis also into biological, physical and geological sciences with implications up to our daily life.The PI has excellent publication records with >330 scientific papers, >7800 citations, and a Hirsch-Index of 44. Despite several risks along the way, the expertise of the PI thus warrants a successful realization of this challenging project.