The sol-gel derived ORMOSIL (organically modified silicate) composed of copolymerized tetramethylorthosilicate (TMOS), methylmethacrylate (MMA), and 3-(trimemoxysilyl)-propylmethacrylate (TMSPM) is a stable host for organic molecules. Due to the ORMOSILs utility as an optical host matrix, it is important to obtain a more detailed understanding of the changes that occur during gelation, aging and drying. A useful probe molecule for this purpose is ReCl(CO)3-2,2'-bipyridine. The emission band of this molecule shows a large blue shift as the medium is changed from fluid to rigid. In this paper the changes that occur during the gelation, aging, and drying of a sol-gel derived ORMOSIL are studied. The emission maximum shifts gradually from 615 ran in the sol to 575 nm in dried gels. The final wavelength is indicative of an environment that is not fully rigid, and suggests that the molecule is in a flexible organic site. The properties of the ORMOSIL are contrasted with those of silicate and aluminosilicate sol-gel matrices.