Structural investigation of the photoinduced spin transition in the [Fe(PM-BIA)2(NCS)2] compound

We investigated the thermo- and photo-induced phase transitions between low spin (LS) and high spin (HS) states of the mol. crystal of [Fe(PM-BiA)2(NCS)2] in the orthorhombic form, by using X-ray diffraction. The structure of the photoinduced HS state, generated from the LS state at low temp., is compared to the structures of the HS and LS phases at thermal equil. and to the thermally trapped HS state. The preliminary results presented here show that the structural reorganization is similar in the different HS states

Nature and mechanism of the photoinduced spin transition in [Fe(PM-BiA)2(NCS)2].

We report the investigation of a prototype cooperative photoinduced spin transition in [Fe(PM-BiA)2(NCS)2] by x-ray diffraction. The structural rearrangement accompanying the change of an electronic state between the low spin and the photoinduced out-of-equilibrium high spin phases is similar to the one occurring around the phase transition at thermal equilibrium. The cooperative behavior of the light-induced optical hysteresis and light-induced thermal hysteresis phenomena investigated here show a strong similarity with thermal hysteresis around first-order phase transitions, since they are driven by a domain nucleation process

Structural investigation of the photoinduced spin transition in the [Fe(PM-BIA)2(NCS)2] compound

We investigated the thermo- and photo-induced phase transitions between low spin (LS) and high spin (HS) states of the mol. crystal of [Fe(PM-BiA)2(NCS)2] in the orthorhombic form, by using X-ray diffraction. The structure of the photoinduced HS state, generated from the LS state at low temp., is compared to the structures of the HS and LS phases at thermal equil. and to the thermally trapped HS state. The preliminary results presented here show that the structural reorganization is similar in the different HS states

Structural investigation of the photoinduced spin conversion in the dinuclear compound {[Fe(bt)(NCS)2]2(bpym)}: toward controlled multi-stepped molecular switches

International audienceThe photocrystallographic investigation of the light-induced excited spin-state trapping effect in the dinuclear spin-crossover compound {[Fe(bt)(NCS)2]2(bpym)} is reported. In this system, each of the two Fe sites may be either in the high-spin (HS) or in the low-spin (LS) state, so that the molecule corresponds to a three-state system (LS-LS, HS-LS and HS-HS). At low temperature, the laser excitation wavelength controls the photoswitching from the stable LS-LS state to one of the metastable excited states (HS-LS or HS-HS), and also between these two excited states. Significant changes in the crystalline structure associated with the photoinduced change of spin state are detailed here. The low-temperature photoinduced states look similar to the corresponding states observed at thermal equilibrium within the unit-cell thermal contraction

Photoinduced spin transition probed by x-ray diffraction

International audienc

Is there a benefit for anesthesiologists of adding difficult airway scenarios for learning fiberoptic intubation skills using virtual reality training? A randomized controlled study

Fiberoptic intubation for a difficult airway requires significant experience. Traditionally only normal airways were available for high fidelity bronchoscopy simulators. It is not clear if training on difficult airways offers an advantage over training on normal airways. This study investigates the added value of difficult airway scenarios during virtual reality fiberoptic intubation training. A prospective multicentric randomized study was conducted 2019 to 2020, among 86 inexperienced anesthesia residents, fellows and staff. Two groups were compared: Group N (control, n = 43) first trained on a normal airway and Group D (n = 43) first trained on a normal, followed by three difficult airways. All were then tested by comparing their ORSIM® scores on 5 scenarios (1 normal and 4 difficult airways). The final evaluation ORSIM® score for the normal airway testing scenario was significantly higher for group N than group D: median score 76% (IQR 56.5–90) versus 58% (IQR 51.5–69, p = 0.0039), but there was no difference in ORSIM® scores for the difficult intubation testing scenarios. A single exposure to each of 3 different difficult airway scenarios did not lead to better fiberoptic intubation skills on previously unseen difficult airways, when compared to multiple exposures to a normal airway scenario. This finding may be due to the learning curve of approximately 5–10 exposures to a specific airway scenario required to reach proficiency