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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 30: Charged Soft Matter, Polyelectrolytes and Ionic Liquids II

CPP 30.4: Vortrag

Mittwoch, 20. März 2024, 15:45–16:00, H 0107

Exploring ATP-Zn²⁺ complexes in water with IR spectroscopy: experiments and ab initio simulations — •emma rossi^1,3, achintya kundu², thomas elsaesser², marialore sulpizi³, and alberta ferrarini¹ — ¹Università degli Studi di Padova, Padova, Italy — ²Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin, Germany — ³Ruhr Universität Bochum, Bochum, Germany

ATP-Zn²⁺ complexes are of significant interest for several applications, including the design of self-assembling systems and catalysis. Understanding the mechanisms behind these applications requires a clear structural characterization of ATP-Zn²⁺. This problem is far from trivial since the presence of charges, highly polarizable species, water and the conformations of the triphosphate chain lead to a wide variety of possible geometries. To elucidate the structure of ATP-Zn²⁺ complexes, we experimentally measured the IR absorption spectra of ATP in water both in the absence and presence of Zn²⁺. Accurate band assignments were performed by comparing the experimental spectra with simulated IR spectra of methyl triphosphate (MTP), a simplified model for ATP, and MTP-Zn²⁺ complexes in a few selected coordination modes. The spectra were obtained through ab initio molecular dynamics trajectories and the time-correlation function method. Using this approach we identified the coordination modes of the ATP-Zn²⁺ complexes predominantly present in solution and we achieved an in-depth molecular understanding of the spectral changes upon formation of the complex.

Keywords: ATP; ab initio molecular dynamics; spectroscopy; water; ions