Mainz 2017 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 9: Posters 1: Dichroism, VUV and Xray, Clusters, and Cold Molecules

MO 9.2: Poster

Dienstag, 7. März 2017, 17:00–19:00, P OG1

Broadband Time-resolved Circular Dichroism Spectroscopy of Hemoglobin — •Heiko Hildenbrand, Andreas Steinbacher, Federico Koch, Marco Schmid, and Tobias Brixner — Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg

Circular dichroism (CD) is a common technique for analyzing chiral samples by their difference in absorption of left and right circularly polarized light. However, chiral signals are small and the typically utilized long optical path lengths, high concentrations, and long integration times in steady-state measurements are not suitable for ultrafast spectroscopy. Hence, only few chirality-sensitive ultrafast time-resolved spectroscopic approaches in the liquid phase have been reported [1,2].

Here we present broadband time-resolved CD spectroscopy which is based on a setup capable of mirroring an arbitrary polarization state of an ultrashort laser pulse. Hence, by passing a circularly polarized broadband probe pulse through this setup we can switch between opposite handedness on a shot-to-shot basis to detect transient CD changes. To demonstrate the capabilities of this approach we investigate the early photochemistry of oxygenated hemoglobin and myoglobin by time-resolved circular dichroism and transient absorption spectroscopy in the visible spectral region, since the spectrometer is capable of acquiring both signals simultaneously.

[1] Meyer-Ilse et al., Laser Photon. Rev. 7, 495 (2013)

[2] Hiramatsu et al., J. Chem. Phys. 143, 121102 (2015)