Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby

Becker PM, Forster C, Carrella LM, Boden P, Hunger D, Van Slageren J, Gerhards M, Rentschler E, Heinze K (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Chemistry - A European Journal Wiley

Book Volume: 26

Pages Range: 7199-7204

Journal Issue: 32

DOI: 10.1002/chem.202001237

Abstract

The chromium(III) complex [Cr^III(ddpd)2]³⁺ (molecular ruby; ddpd=N,N′-dimethyl-N,N′-dipyridine-2-yl-pyridine-2,6-diamine) is reduced to the genuine chromium(II) complex [Cr^II(ddpd)2]²⁺ with d⁴ electron configuration. This reduced molecular ruby represents one of the very few chromium(II) complexes showing spin crossover (SCO). The reversible SCO is gradual with T1/2 around room temperature. The low-spin and high-spin chromium(II) isomers exhibit distinct spectroscopic and structural properties (UV/Vis/NIR, IR, EPR spectroscopies, single-crystal XRD). Excitation of [Cr^II(ddpd)2]²⁺ with UV light at 20 and 290 K generates electronically excited states with microsecond lifetimes. This initial study on the unique reduced molecular ruby paves the way for thermally and photochemically switchable magnetic systems based on chromium complexes complementing the well-established iron(II) SCO systems.

Involved external institutions

Johannes Gutenberg-Universität Mainz (JGU)

Germany (DE) Technische Universität Kaiserslautern

Germany (DE) Universität Stuttgart

Germany (DE)

How to cite

APA:

Becker, P.M., Forster, C., Carrella, L.M., Boden, P., Hunger, D., Van Slageren, J.,... Heinze, K. (2020). Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby. Chemistry - A European Journal, 26(32), 7199-7204. https://doi.org/10.1002/chem.202001237

MLA:

Becker, Patrick M., et al. "Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby." Chemistry - A European Journal 26.32 (2020): 7199-7204.

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