title: Absorption and Raman study for POSS-oligophenylene nanohybrid molecules.
abstract: Photoluminescence excitation and Raman measurements have been conducted for hybrid materials in which the oligophenylene derivatives are attached to the corners of a cubic inorganic cage of Polyhedral Oligosilsesquioxane (POSS). The theoretical study for energy levels and probable transitions between occupied orbital to un-occupied orbital and corresponding intensity for the hybrid molecule has been performed using density functional theory electronic structure program-DMol. The comparison between the theoretical and experimental results leads to a possible assignment for the excitation peaks in the PLE spectra. Moreover, the Raman bands of the conjugated chains in these materials are red-shifted and broadened with respect to their bulk counterparts. This systematic peak shift and broadening of the Raman bands provided additional confirmation that the conjugated chains in hybrid materials of bulk state are isolated without obvious pi-pi stacking and therefore the excitons in the organic arms are confined in the system.
authors.affiliation: Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiao
authors.forename: Sudhiranjan
authors.initials: S
authors.lastname: Tripathy
authors.forename: Tingting
authors.initials: T
authors.lastname: Lin
authors.forename: Chaobin
authors.initials: C
authors.lastname: He
mesh_terms: D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D017646:Organosilicon Compounds / Q000737:chemistry* / Q000528:radiation effects; D010316:Particle Size; D012542:Scattering, Radiation; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D017646:Organosilicon Compounds