Visualizing the coordination-spheres of photoexcited transition metal complexes with ultrafast hard X-rays.

The concept of coordination sphere (CS) is central to the rational development of hierarchical molecular assemblies in modern chemistry. Manipulating the organization around transition metal ions with covalent and supramolecular interactions is a general strategy that underlies most synthetic protocols. Achieving similar control for photoexcited molecular complexes is necessary to advance the design of light-driven functionalities. This objective calls for monitoring the ultrafast dynamics of the primary (1-CS) and the secondary (2-CS) coordination spheres on the atomic scale, which remains to date an important experimental challenge for short-lived species. In this work, transient wide-angle scattering of hard X-rays (25 keV) is employed with state-of-the-art AIMD simulations in order to visualize the 1-CS (solute-only) and the 2-CS (solvation cage) of the photoinduced high-spin (HS) state for [Fe(bpy)3]2+ (bpy = 2,2'-bipyridine) in aqueous solution. Correlating this structural information in real-space reveals the interlacing of the two CS, which in turn explains why solvation affects the photoinduced electronic and structural dynamics in this class of complexes. More generally, these results obtained for a prominent prototypical system in ultrafast X-ray sciences demonstrate the unique perspectives offered by this technique to gain the crucial knowledge about the multiscale solvation dynamics that is currently missing for controlling the solute-solvent interactions in advanced functional nano and biomaterials employed for photoconversion.

[The use of perftoran in patients with burn shock]. / Primenenie of perftorana u bol'nykh s ozhogovym shokom.

Basing on studying of the biogenic amines metabolism and indexes of cardiodynamics in 49 patients with the burn shock of middle severity it was established, that performance of single infusion of perftoran preparation in the first day of the burn trauma had stimulated the organism adaptation reconstruction due to demolition of the catecholamines metabolism dysbalance, prevalence of stress-limiting processes in the reply to stress structure, formation of moderate hyperdynamics of blood circulation. The double infusion of the preparation had permitted to guarantee the indexes stabilization during all acute period of the burn disease.