Related Experiment Video
Updated: Jul 1, 2025
Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Investigation of the molecular switching process between spin crossover states of triazole complexes as basis for
Axel Günther1,2,3, Yves Deja4, Maximilian Kilic5
1Hannover Centre for Optical Technologies, Leibniz University of Hannover, 30167, Hannover, Germany. axel.guenther@hot.uni-hannover.de.
Abstract:
With the advent of the first laser sources and suitable detectors, optical sensor applications immediately also came into focus. During the last decades, a huge variety of optical sensor concepts were developed, yet the forecast for the future application potential appears even larger. In this context, the development of new sensor probes at different scales down to the atomic or molecular level open new avenues for research and development. We investigated an iron based triazole molecular spin-crossover complex changing its absorption characteristics significantly by varying environmental parameters such as humidity, temperature, magnetic or electric field, respectively, with respect to its suitability for a new class of versatile molecular sensor probes. Hereby, besides the investigation of synthesized pure bulk material using different analyzing methods, we also studied amorphous micro particles which were applied in or onto optical waveguide structures. We found that significant changes of the reflection spectra can also be obtained after combining the particles with different types of optical waveguides.The obtained results demonstrate the suitability of the material complex for a broad field of future sensor applications.
Related Concept Videos
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
02:52Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
01:26Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
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...
01:08NMR Spectroscopy: Spin–Spin Coupling
01:58Cooperative Allosteric Transitions