Institut de Chimie Moléculaire et des Matériaux d'Orsay

Laboratoire de Chimie Inorganique - LCI

Mecanism and dynamic of the spin-state photoswitching

Marie-Laure Boillot
Olga Iasco (post-doc), Jérôme Lainey (Ph.D. candidate), Luong-Lam Nguyen (Ph.D. candidate)




Fe(III) complex, Single-crystal, Phase Transition, Cooperativity (a)

The ultra-fast photoswitching of a cooperative spin-transition FeIII solid produces, via single-crystal NIR excitations, first, the low-spin LMCT (170 fs time decay), then the high-spin excited state.

Fe(III) molecular crystals, time resolved X-ray diffraction (ps) and optical spectroscopy (fs) (b)

The out-of-equilibrium switching dynamics triggered by femtosecond laser flash has been investigated for two Fe(III) spin-crossover polymorphs. TR X-ray diffraction and optical results have revealed the nature and time-scale of several consecutive steps in the photoswitching of these  molecular materials.


Recent publications

Cascading photo-, elasto- and thermo-switching of spin-state triggered by femtosecond laser pulse in an Fe(III) molecular crystal. M. Lorenc et al, Phys. Rev. B., 2012, 85, 054302-8. See also E. Collet et al, Chem. Eur. J., 2012, 18, 2051. E. Collet et al, Phys. Chem. Chem. Phys. 2012, 14, 6192. The cooperative spin-state transition of an iron(III) compound [FeIII(3-MeO-SalEen)2]PF6: thermal-vs. ultra-fast photo-switching. A. Tissot et al, J. Mater. Chem., 2011, 21, 18347-18353.

Fe(III) complex, nanocrystals, fs optical spectroscopy, dynamics (a)

Femtosecond optical pump-probe spectroscopy is used to study photoswitching dynamics of Fe(III) spin-crossover nanocrystals. Results indicate that up to 10% of the molecules can be photoswitched from LS to HS states within less than 1 ps.

Fe(III) complex, Raman, pressure, fs optical spectroscopy (b)

We use magnetic, Raman, X-ray diffraction and time-resolved optical measurements to investigate the static and dynamic properties of a Fe(III) catecholate spin-crossover complex. The out-of-equilibrium photo-induced processes are compared with spin-crossover driven by temperature and pressure.



Recent publications

Femtosecond Spin-State Photoswitching of Molecular Nanocrystals Evidenced by Optical Spectroscopy. R. Bertoni et al, Angew. Chem., Int. Ed., 2012, 51, 7485.

Temperature- and Pressure-Induced Switching of the Molecular Spin-state of an Orthorhombic Iron(III) Spin-Crossover Salt. A. Tissot et al, Eur. J. Inorg. Chem., 2013, 1001. Spin-State Photoswitching Dynamics of the [(TPA)Fe(TCC)]SbF6 complex. W. Kaszub et al,  Eur. J. Inorg. Chem., 2013, 992.



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