Related Experiment Video
Updated: Jun 12, 2026
Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems
Published on: February 10, 2020
Photoinduced charge-transfer process in rubidium manganese hexacyanoferrate probed by Raman spectroscopy
R Fukaya1, M Nakajima, H Tokoro
1Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan. fukaya@issp.u-tokyo.ac.jp
Abstract:
The photoinduced charge-transfer process in Rb(0.94)Mn[Fe(CN)(6)](0.98).0.2H(2)O is investigated by observing the valence states of the metal ions by Raman spectroscopy. The sample in the high-temperature phase is irradiated at the ligand to metal, CN(-)-->Fe(III) and charge-transfer band (lambda=395 nm). The Fe(III)-CN-Mn(II) pair valence state corresponding to the high-temperature configuration is totally depleted after prolonged irradiation, and the Fe(II)-CN-Mn(III) pair valence state corresponding to the low-temperature configuration appears. In addition, two kinds of CN stretching modes, ascribed to Fe(II)-CN-Mn(II) and Fe(III)-CN-Mn(III) pair valence states, are found. The photoproduction process of each pair valence states is well reproduced by a kinetic model assuming a charge transfer from Mn(II) to Fe(III). During irradiation, continuous shifts of the Raman peaks are found and ascribed to a release of the strain due to the lattice mismatching between the high-temperature and the photoinduced phases. This behavior indicates that the photoinduced phase created locally in the high-temperature-phase lattice grows up to a photoinduced phase domain. The conversion efficiency is lowered with decreasing temperature, indicating the existence of an energy barrier. We propose a model, which can explain the existence of an energy barrier in the electronic excited state.
Related Concept Videos
01:20Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:26Raman Spectroscopy Instrumentation: Overview
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
01:13¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
01:08Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must have a...