Issue 28, 2022

Photoinduced Jahn–Teller switch in Mn(iii) terpyridine complexes


Ultrafast transient absorption spectra were recorded for [Mn(terpy)X3], where X = Cl, F, and N3, to explore photoinduced switching from axial to equatorial Jahn–Teller (JT) distortion. Strong oscillations were observed in the transients, corresponding to a wavepacket on the excited-state potential energy surface with oscillation frequency around 115 cm−1 for all three complexes. Multireference quantum chemistry calculations indicate that the reaction coordinate is a pincer-like motion of the terpyridine ligand arising from bond length changes in the excited state due to the JT switch. We observed long dephasing times of the wavepacket, with times of 620 fs for [Mn(terpy)Cl3], 450 fs for [Mn(terpy)F3], and 370 fs for [Mn(terpy)(N3)3]. The dephasing time of these coherences decreases with an increasing number of vibrational modes at lower energy than the mode dominating the reaction coordinate, suggesting they act as an effective bath to dissipate the excess energy obtained from photoexcitation.

Graphical abstract: Photoinduced Jahn–Teller switch in Mn(iii) terpyridine complexes

Supplementary files

Article information

Article type
22 Mar 2022
09 May 2022
First published
10 May 2022
This article is Open Access
Creative Commons BY license

Dalton Trans., 2022,51, 10751-10757

Photoinduced Jahn–Teller switch in Mn(III) terpyridine complexes

K. Barlow, J. Eng, I. Ivalo, M. Coletta, E. K. Brechin, T. J. Penfold and J. O. Johansson, Dalton Trans., 2022, 51, 10751 DOI: 10.1039/D2DT00889K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity