The spatial diffusion and size distribution of monodisperse silver nanoclusters synthesized via Ag(I) carboxylate in zeolite Y cages are investigated in nanostructured water films on silicon dioxide (SiO 2 ) and mica surfaces with optical and atomic force techniques. Subnanometer clusters escaping the zeolite Y cage show a strong and photostable fluorescence emission in the visible range and allow for optical singlecluster tracking. Heterogeneous diffusion dynamics reflect the transition from an ice-like to a liquid-like water film as a function of film thickness. The contributions of the different diffusion coefficients strongly correlate with the water film thickness and the chemical composition of the interface. The heterogeneity of the diffusion is caused by ad-and desorption of Ag clusters to silanol groups at the SiO 2 interface which couple vibronically to the Ag clusters as can be seen from single cluster fluorescence spectra.

The adsorption of the photochromic 1,3,3-trimethyl-6′-nitroindoline-2-spiro-2′-benzopyran (SP) on Y-zeolites from dichloromethane solution and the ship in the bottle reaction (SIBOR) of SP have been studied by measuring the UV/vis absorption of the resulting materials to achieve information on polarity of the internal and external surface environments. The acidity and α values (hydrogen bond donating ability) of the faujasites significantly differ whether the probe is located at the external surface or inside the Y-zeolite. Additionally, dicyanobis(1,10-phenanthroline)iron(II) [Fe(phen)2(CN)2] (1) and 4-tert-butyl-2-(dicyanomethylene)-5-[4-(diethylamino)benylidene]-Δ3-thiazoline (2) were used as solvatochromic probes for the external surface. The empirical Kamlet−Taft polarity parameter α (hydrogen bond donating (HBD) ability) and π* (dipolarity/polarizability) have been determined for the faujasites surfaces using the linear solvation energy relationship (LSER).

SummaryNovel chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9-carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β-dimethylcyclodextrin or by pre-adsorption onto silica particles. Furthermore, 1 was converted with isopropylamine into the model compound 1-M. All new compounds were characterized by NMR, FTIR, UV–vis and fluorescence spectroscopy. The solvent-dependent UV–vis absorption and fluorescence emission band positions of the model compound and the carbonitrile-functionalized PVAm were studied and interpreted using the empirical Kamlet–Taft solvent parameters π * (dipolarity/polarizability), α (hydrogen-bond donating capacity) and β (hydrogen-accepting ability) in terms of the linear solvation energy relationship (LSER). The solvent-independent regression coefficients a, b and s were determined using multiple linear correlation analysis. It is shown, that the chains of the polymer have a significant influence on the solvatochromic behavior of 1-P. The structure of the carbonitrile 1-Si bound to polymer-modified silica particles was studied by means of X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) measurements. Fluorescent silica particles were obtained as shown by fluorescence spectroscopy with a diffuse reflectance technique.

Precisely nano-sized aluminosilicate particles (average diameter size 50 to 80 nm) with tailor-made internal surface polarity are suitable as host material for photochromic dyes of the chromene type in order to produce optical transparent photoswitchable polymer films. The sophisticated host material does accomplish two important requirements for a technical application, appropriate internal space for the light induced reversible switching process of the adsorbed dye and suppression of disturbing chemical reactions. The adjustment of the internal surface polarity of the host material was achieved by silane reagents which could be observed by means of specific solvatochromic probes

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