Abstract: Sol-gel process for producing a photochromic composite material includes successive stages of hydrolysis, condensation, and drying, in which an alkoxysilane is selected as a precursor, and a ruthenium complex with a nitrosyl ligand is selected as a photochromic complex, and, in combination, the sol-gel process is implemented starting from the selected precursor and photochromic complex, with successive stages of hydrolysis, arrangement in a container of a selected shape, condensation, curing and aging, whereby this latter stage includes a final drying cycle, and for, the curing and aging stages, the pH, temperature and duration are selected so that in the produced xerogel, whose shape is determined by that of the container, the photochromic ruthenium complex with a nitrosyl ligand, in the crystalline state and in the form of nanoparticles, is inserted into the nanopores of the silica matrix, distributed in an at least substantially homogeneous way.

Abstract: Sol-gel process for producing a photochromic composite material, in which there is a precursor and a photochromic complex; the process includes successive stages of hydrolysis, condensation, and drying, in which: —an alkoxysilane is selected as a precursor, and a ruthenium complex with a nitrosyl ligand is selected as a photochromic complex, and, in combination, —the sol-gel process is implemented starting from the selected precursor and photochromic complex, with successive stages of hydrolysis, arrangement in a container of a selected shape, condensation, curing and aging, whereby this latter stage includes a final drying cycle, and—for the curing and aging stages—the pH, temperature and duration are selected so that in the produced xerogel, whose shape is determined by that of the container, the photochromic ruthenium complex with a nitrosyl ligand, in the crystalline state and in the form of nanoparticles, is inserted into the nanopores of the silica matrix, distributed in an at least substantially homoge

Abstract: A stable solution of molecular material includes a first type of organic or organometallic molecule and a second type of organic or organometallic molecule or of ion. The first type has groups allowing electron delocalization. The solution further includes a third type of molecule that may be a surfactant or a solvent, capable of combining with the first or the second type of molecule or of ion), to form an adduct in solution whose presence prevents the precipitation of a compound formed by reaction between the first and second types of molecules, and makes it possible to obtain solutions whose concentration of the compound is greater than that governed by the precipitation constant of the compound in the absence of molecules of the third type.