The synthesis and processing of nanoparticles consisting of metallic nanocrystal cores and organic monolayer shells promise interesting technological applications. Here, we report the synthesis of gold nanoparticles modified with ionic liquids based on the imidazolium cation. Aggregation-induced color changes of the gold nanoparticles in an aqueous solution were used as an optical sensor for anions via anion exchange of ionic liquid moiety. We also demonstrated the phase transfer of the gold nanoparticles from aqueous media to ionic liquid.

Polysilsesquioxanes are regarded as organic-inorganic hybrid materials at a molecular level. We can readily tune the properties of the materials for realizing the desired ones by changing the contents or types of organic components. In addition, the hierarchical structures have potential for generating further characteristics distinctly different from those of the constituents. From this viewpoint, polyhedral oligomeric silsesquioxane (POSS) is attractive as a cornerstone in highly ordered materials. In this review, we survey recent studies on modified POSS-based functional materials and particularly explain the design concepts for applying the significant characteristics of POSS for the material properties. In the initial sections, we introduce the examples concerning intrinsic properties of POSS such as thermal stability, mechanical property, and structural features. In the latter sections, we describe the application of POSS-based materials for bio-relating functional materials. We describe the validity of POSS for molecular designing of the advanced imaging tools.

The emission process of the o-carborane dyad with anthracene originating from the twisted intramolecular charge transfer (TICT) state in the crystalline state is described. The anthracene-o-carborane dyad was synthesized and its optical properties were investigated. Initially, the dyad had aggregation- and crystallization-induced emission enhancement (AIEE and CIEE) properties via the intramolecular charge transfer (ICT) state. Interestingly, the dyad presented the dual-emissions assigned to both locally excited (LE) and ICT states in solution. From the mechanistic studies and computer calculations, it was indicated that the emission band from the ICT should be attributable to the TICT emission. Surprisingly, even in the crystalline state, the TICT emission was observed. It was proposed from that the compact sphere shape of o-carborane would allow for rotation even in the condensed state.

Construction of organic−inorganic hybrid materials with controlled mineralization analogous to those produced by nature is now of current interest for both organic and inorganic chemists to understand the mechanism of the natural biomineralization process as well as to seek industrial and technological applications. This review provides a general survey of recent research on control of crystal nucleation and growth of calcium carbonate by synthetic substrates from the viewpoint of organic and polymer chemistry. Model systems in which low-molecular-weight, linear polymeric, and dendritic organic additives are used to study the effect of molecular properties such as charge and functionality on inorganic crystallization are providing insights into the possible mechanisms operating in biology. To probe the organic−inorganic interface and resolve some of the molecular events mediating template-directed crystal nucleation and growth, a simple model surface, that is, compressed monolayers at the air/water interface and self-assembled monolayers on a solid surface, was used for the nucleation of oriented inorganic materials. The template-inhibition strategy for the synthesis of CaCO3 thin film has also been reported. Microscale phase separation in reaction media has importance in the synthesis of inorganic materials with unusual form and hierarchical structure. These interesting efforts have led to fundamental developments in areas relating to the biomineralization process, which is expected to be the impetus for the next industrial revolution.

16) Chien et al. also reported trimodal GPC curves for the ringopening cationic polymerization of 1,3,6-trioxocane and 2-butyl-1,3,6-trioxocane.21 They assumed that the fraction eluted with the smallest retention volume corresponded to the linear high molecular weight polymer and the fractions at higher retention volumes were probably the macrocycles. (17) Okamura, S.; Hayashi, K.; Kitanishi, Y. J. Polym. Sci. 1962, 58, 925. (18) This rearrangement, as proposed by the Freiburg group,9 makes progress at the Ostwald-Ripening mechanism supported by the vaporization-condensation theory of Lifshitz-Slyozov:22 small particles with a high vapor pressure have a tendency to redissolve and depolymerize into the monomer and large particles further grow by a chain-propagation reaction in order to minimize the excess interfacial free energy of the whole system.

In this article, we report the unique optical characteristics of boron diiminates in the solid states. We synthesized the boron diiminates exhibiting aggregation-induced emission (AIE). From the series of optical measurements, it was revealed that the optical properties in the solid state should be originated from the suppression of the molecular motions of the boron diiminate units. The emission colors were modulated by the substitution effects (λ(PL,crystal) = 448-602 nm, λ(PL,amorphous) = 478-645 nm). Strong phosphorescence was observed from some boron diiminates deriving from the effects of two imine groups. Notably, we found some of boron diiminates showed crystallization-induced emission (CIE) properties derived from the packing differences from crystalline to amorphous states. The 15-fold emission enhancement was observed by the crystallization (Φ(PL,crystal) = 0.59, Φ(PL,amorphous) = 0.04). Next, we conjugated boron diiminates with fluorene. The synthesized polymers showed good solubility in the common solvents, film formability, and thermal stability. In addition, because of the expansion of main-chain conjugation, the peak shifts to longer wavelength regions were observed in the absorption/emission spectra of the polymers comparing to those of the corresponding boron diiminate monomers (λ(abs) = 374-407 nm, λ(PL) = 509-628 nm). Furthermore, the absorption and the emission intensities were enhanced via the light-harvesting effect by the conjugation with fluorene. Finally, we also demonstrated the dynamic reversible alterations of the optical properties of the polymer thin films by exposing to acidic or basic vapors.

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