Solution and solid-state Silicon-29 NMR spectroscopy, X-ray diffraction (WAXS), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and differential scanning calorimetric were used for the characterization of organic-inorganic hybrids, obtained from 4-[5-dichloromethylsilyl]pentyl]oxy]-cyanobenzene (DCN) and tetraethoxysilane (TEOS). Presence of reaction intermediates during chemical reactions was characterized by NMR. The hybrids are mainly composed of a siloxane copolyrner with silicate units. Copolymer has pendant groups of pentyl-cyanobenzene that behave as chromophores. The nature of ordered-disordered phases was analyzed by X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Ordered phase has a mesogenic structure containing the siloxane copolymer. The disordered phase is mainly silica glass. Molecular modeling for an idealized section of the copolymer suggests that pentyl-oxy-cyanobenzene side-chains align as rigid mesogens along the polymer backbone. Hybrids present self diffraction patterns in coherent luminous rings forms. These patterns indicate the presence of nonlinear optic (NLO) properties. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 794-804, 2009