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UV/Vis absorption data of (E)-4-(2-[5-{4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl}thiene-2-yl]vinyl)-2-(dicyano-methylene)-3-cyano-5,5-dimethyl-2,5-dihydrofuran (ThTCF) as a solvatochromic probe is applied to examine the anion coordination strength (e.g. of N(CN)2, BF4, PF6, N(Tf)2, CF3COO) as a function of the cation structure of ionic liquids. Several 1-n-alky-3-methylimidazolium- and tetraalkylammonium CH3-NR3+-based ILs with different n-alkyl chain lengths (R = –C4H9, –C6H11, –C8H17, –C10H21) are considered. UV/Vis absorption data of ThTCF show subtle correlations with hydrogen bond accepting (HBA) ability-related measurands such as Kamlet–Taft β, Freire's EHB, and Laurence β1 parameter as a function of anion and cation structure. The different influence of the n-alkyl chain length of imidazolium- and tetraalkylammonium-based ILs on the dipolarity and HBA strength is confirmed by comparison with the 14N isotropic hyperfine coupling constants (Aiso) of a positively (CATI) and negatively charged spin probe (TSKCr) of TEMPO-type [(2,2,6,6-tetramethylpiperidin-1-yl)oxyl] and quantum chemically derived dipoles of the cations. The Aiso values correlate with the absorption energy of ThTCF and EHB, but in different ways depending on the anion or charge of the spin probe. In a final discussion of the β, EHB, and β1 scales in relation to ThTCF, the importance of the molar concentration N of ionic liquids for the physical significance of the respective parameters is discussed. [ABSTRACT FROM AUTHOR]

The germylenes, germanium(ii) 2-(oxidomethyl)phenolate (1), germanium(ii) 4-methyl-2-(oxidomethyl)phenolate (2) and germanium(ii) 4-bromo-2-(oxidomethyl)phenolate (3) were synthesized and their thermally induced twin polymerization to give organic–inorganic hybrid materials was studied. The compounds 1–3 form oligomers including dimers, trimers and tetramers as a result of intermolecular coordination of the benzylic oxygen atom to germanium. The structural motifs were studied by single crystal X-ray diffraction analysis and DFT-D calculations. Thermally induced twin polymerization of these germylenes gave hybrid materials based on germanium-containing phenolic resins. Carbonization of these resins under reductive conditions resulted in porous materials that are composed of germanium and carbon (Ge@C materials), while oxidation with air provided non-porous germanium dioxide. The porous Ge@C materials were tested as potential anode materials for rechargeable Li-ion batteries. Reversible capacities of 540 mA h g−1 were obtained at a current density of 346 mA g−1 without apparent fading for 100 cycles, which demonstrates that germanium is well accessible in the hybrid material. [ABSTRACT FROM AUTHOR]

Nucleophilic substitution of fluoroaromatics with poly(vinyl amine) (PVAm) is a suitable method for producing various azobenzene-functionalized PVAms. The solubility of the fluoroaromatic reagents in water was mediated by complexation with 2,6-O-dimethyl-β-cyclodextrin (DMCD). The degree of functionalization has been determined using model compounds as reference system. The solvatochromic properties of the polymers and the model compounds have been studied and interpreted using the well-established linear solvation energy relationships (LSER) of Kamlet–Taft and Catalán. The most dominant effect on the solvatochromic behavior is caused by interactions with solvents of a different dipolarity/polarizability. Also the basicity of the solvents is assumed to play an important role in the solvatochromism of the azobenzene-functionalized PVAms which shows the influence of the polymer chains. Furthermore, the UV/vis absorption spectra show a bathochromic shift with increasing acid strength of the medium. The impact of the PVAm backbone on the color of the chromophore bonded is highlighted. [ABSTRACT FROM AUTHOR]

The solid state complexes, solvatochromic and acidochromic behaviour of four merocyanine-type dyes derived from barbituric and thiobarbituric acid and their use as solvatochromic probe molecules for coloured surfaces are described. The dyes were obtained by condensation reaction of barbituric, N-methylbarbituric, N,N′-dimethylbarbituric and thiobarbituric acid with 4-N,N-dimethylaminocinnamaldehyde. The dyes were characterised by means of liquid and solid state NMR techniques (1H MAS NMR, 1H–1H DQ MAS NMR, 13C CPMAS NMR), single-crystal X-ray analysis, UV/vis and IR measurements. The solvatochromism has been investigated in 43 solvents and interpreted in terms of Kamlet–Taft parameters α, β, and π*. Altogether, the solvatochromic properties of these four dyes were determined mainly by the hydrogen bond donating (HBD) ability and the polarisability/dipolarity of a solvent. The interactions of the dyes with oxidic and metal surfaces were studied. Their perichromic behaviour was compared with that of established solvatochromic dyes for the determination of α, β, and π*, namely dicyano-bis-(1,10-phenanthroline)-iron(ii)-complex (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b′]-difuran-2,6-dione (2) and 4-tert-butyl-2-(dicyanomethylene)-5-[4-(diethylamino)benzylidene]-Δ3-thiazoline (3). The barbituric acid dyes were used to probe the surface polarity of coloured oxides like tungsten(vi) oxide and iron(iii) oxide. The interactions between the dyes and metals like zinc and aluminium were also investigated. [ABSTRACT FROM AUTHOR]

An organic-inorganic hybrid material derived from covalently grafting a palladium complex of the type (L)2PdCl2 (L = Si(OMe)3 functionalized PPh3) on silica was synthesized, characterized and sucessfully applied as a catalyst for the Suzuki reaction. [ABSTRACT FROM AUTHOR]

An organic-inorganic hybrid material derived from covalently grafting a palladium complex of the type (L)(2)PdCl(2) (L = Si(OMe)(3) functionalized PPh(3)) on silica was synthesized, characterized and sucessfully applied as a catalyst for the Suzuki reaction.