Absorption, resonance Raman and resonance CARS investigations on the permanganate ion doped in potassium perchlorate single crystals at low temperatures

Abstract

Solid-state absorption, resonance Raman and resonance CARS spectroscopy were applied to investigate the vibronic properties of the permanganate ion doped in KCIO, single crystals. Experiments were performed for all three types of spectroscopy at 15 K. At this temperature the vibronic structure in the absorption spectrum is highly resolved, allowing detailed studies of resonance Raman and resonance CARS spectroscopy. Selected experimental results are presented.

A vibrational and conformational characterization of arginine at different pH values investigated using Raman spectroscopy combined with DFT calculations

“…However, to the best of our knowledge, a detailed combined study on the vibrational and conformational characterization of Arg at different protonation states (pH values) based on Raman spectroscopic results, DFT calculations (explicit and implicit), and thermodynamical analysis is still lacking in the literature. The pioneering work of Prof. Wolfgang Kiefer demonstrated that Raman spectroscopy is a powerful tool for the study of the structure of biomolecules . We focus here only on the investigation of the structural modification of Arg in accordance with/in response to the changes in the Raman spectra due to protonation as a function of pH in a liquid water environment.…”

Orchestrating Nuclear Dynamics in a Permanganate Doped Crystal with Chirped Pump–Probe Spectroscopy

“…The static absorption profile features a clearly resolved progression of vibronic transitions separated by ∼760 cm –1 , the dominant vibrational quantum in the S 1 state. Additionally, three other electronic absorption bands are present in the UV, far off-resonance for the present experiments …”

“…The current study demonstrates how to achieve species and state selectivity by pulse chirp control, monitoring the vibrational dynamics in a photoactive system of intrinsic interest, namely the permanganate ion MnO 4 , a strong nontoxic oxidizing agent, essential for medical uses, water and food treatments, 42,43 with applications in analytical chemistry and in the synthesis of organic compounds. 44 In its solid form, KMnO 4 presents an orthorhombic crystal structure (Figure 1(d)), with a typical deep purple color due to the transition from the ground state S 0 to the first optically active excited electronic state (hereafter defined as S 1 ), 45,46 centered in the visible, and responsible for the absorption shown in Figure 1(c).…”

“…Additionally, three other electronic absorption bands are present in the UV, far offresonance for the present experiments. 46 Subtracting the slow transient absorption response from the recorded data allows for isolating the coherent vibrational oscillations. Then, the ISRS power spectrum in the frequency domain is retrieved by fast Fourier transformation (FFT) over ΔT (Figure 2).…”

“…In its solid form, KMnO 4 presents an orthorhombic crystal structure (Figure (d)), with a typical deep purple color due to the transition from the ground state S 0 to the first optically active excited electronic state (hereafter defined as S 1 ), , centered in the visible, and responsible for the absorption shown in Figure (c).…”