Solid State Photoinduced Transformations
We investigate ground-state, thermal-equilibrium states and out-of-equilibrium states (photoinduced) and different types of transformations in crystals and condensed matter, by combining visible optical spectroscopy and advanced crystallography. We study various systems undergoing both thermally-induced and photoinduced transformation and coordination complexes, such as spin-crossover compounds, charge-transfer complexes, Prussian blue analogues or ruthenium compounds with nitrosyl ligands. Advanced structural studies allow characterizing, at the atomic scale, the different phases of the crystalline samples and the complex ordering phenomena and structural reorganization at the intra-and inter-molecular levels, especially in the photoinduced state. Our studies are performed both at thermal equilibrium and under light irradiation by using photocrystallography, possibly at low temperatures and/or high pressure. We pay a special attention to the symmetry-breaking analysis, if any, and provide deep analysis during multi-step processes as well as on the transformation rate that we try to optimize playing on the experimental conditions (laser wavelength, laser polarization, sample shape, …). The objective is first to understand and then to control by light the physical properties of the materials such as magnetism, conductivity, colour...
Collaboration
Shin-ichi Ohkoshi, Hiroko Tokoro, Seiji Miyashita, Koichiro Tanaka, LIA IM-LED, Japan
Isabelle Malfant, LCC Toulouse, France
Grace Morgan, Dublin, Irland
Jose-Antonio Real, Spain
Références récentes
Two-Step Photon Absorption Driving the Chemical Reaction in the Model Ruthenium Nitrosyl System [Ru(py)4Cl(NO)](PF6)2·1/2H2O
L. Khadeeva, W. Kaszub, M. Lorenc, I. Malfant, M. Buron-Le Cointe,
Inorganic Chemistry, American Chemical Society, 2016, 55 (9), pp.4117-4123 - doi:10.1021/acs.inorgchem.5b02572
Ordering phenomena of high-spin/low-spin states in stepwise spin-crossover materials described by the ANNNI model
H. Watanabe, K. Tanaka, N. Bréfuel, H. Cailleau, J.-F. Létard, S. Ravy, P. Fertey, M. Nishino, S. Miyashita, E. Collet,
Phys. Rev. B, 2016, 93 (1), pp.014419 - doi:10.1103/PhysRevB.93.014419
Inside Thermal Hysteresis studied by x-ray diffraction Current
E. Collet, L. Henry, L. Piñeiro-López, L. Toupet, J.A. Real Single Laser Shot Spin State Switching of {Fe II (pz)[Pt(CN) 4 ]}
Inorganic Chemistry, 2016, 6, pp.61 - doi:10.2174/1877944105666150910233704
Electronic vs. structural ordering in a manganese(III) spin crossover complex Chemical Communications
A. Anthony J. Fitzpatrick, E. Trzop, H. Müller-Bunz, M. M. Dîrtu, Y. Garcia, E. Collet, G. G. Morgan ,
Royal Society of Chemistry, 2015, 51 (99), pp.17540-17543 - doi:10.1039/c5cc05129k