Two-dimensional infrared spectroscopy (2D-IR spectroscopy) is powerful technique adding additional information to already information-rich mid-IR spectra. By revealing a second frequency-axis , the excitation frequency, and adding a time-axis, a 2D-IR spectrum gives us information over vibrational coupling, anharmonicity, vibrational lifetimes, relative orientations and spectral diffusion rates of vibrational bands. Here we present a state-of-the art 2D-IR spectrometer using a fixed target chip [1] to measure different samples in rapid succession.

Our setup is based on a Spitfire Ace (10W, 1 kHz, 40 fs @ 800nm) from which 9W are used to generate high-energy mid-IR femtosecond pulses (up to 70mW) by employing a TOPAS HE module with a NDFG-extension. The mid-IR is directed into an AOM-based 2D-spectrometer (Phasetech) employing a 128x128 pixel MCT. To minimize the required sample-amount and to increase the number of different samples, the HARE chip is employed. The chip (30mm x 30mm) consists of 20736 micro wells, each can be filled differently employing a picolitre dispenser. During measurement, the chip is moved to different sample wells using a xyz-stage, interweaving the different measurements and thereby minimizing systematic errors.

A proof-of-concept measuring the 2D-IR spectra of N-methylacetamide at 20 different pH values is presented. Ot

[1] Mehrabi, P., Muller-Werkmeister, H.M., Leimkohl, J.-P., Schikora, H., Ninkovic, J., Krivokuca, S., Andricek, L., Epp, S.W., Sherrell, D., Owen, R. L., Pearson, A.R., Tellkamp, F., Schulz, E.C. & Miller, R.J.D. (2020). J. Synchrotron Rad. 27, 360-370.