We present a new family of water-soluble copper(ii) carbosilane metallodendrimers. The combined experimental and theoretical analysis reveals that they display different interactions with model membranes, which also dictate their antitumor behavior.

The indoline dyes D102, D131, D149, and D205 have been characterized when adsorbed on fluorine-doped tin oxide (FTO) and TiO2 electrode surfaces. Adsorption from 50:50 acetonitrile−tert-butanol onto fluorine-doped tin oxide (FTO) allows approximate Langmuirian binding constants of 6.5 × 104, 2.0 × 103, 2.0 × 104, and 1.5 × 104 mol−1 dm3, respectively, to be determined. Voltammetric data obtained in acetonitrile/0.1 M NBu4PF6 indicate reversible one-electron oxidation at E mid = 0.94, 0.91, 0.88, and 0.88 V vs Ag/AgCl(3 M KCl), respectively, with dye aggregation (at high coverage) causing additional peak features at more positive potentials. Slow chemical degradation processes and electron transfer catalysis for iodide oxidation were observed for all four oxidized indolinium cations. When adsorbed onto TiO2 nanoparticle films (ca. 9 nm particle diameter and ca. 3 μm thickness on FTO), reversible voltammetric responses with E mid = 1.08, 1.16, 0.92, and 0.95 V vs Ag/AgCl(3 M KCl), respectively, suggest exceptionally fast hole hopping diffusion (with D app > 5 × 10−9 m2 s−1) for adsorbed layers of all four indoline dyes, presumably due to π−π stacking in surface aggregates. Slow dye degradation is shown to affect charge transport via electron hopping. Spectroelectrochemical data for the adsorbed indoline dyes on FTO-TiO2 revealed a red-shift of absorption peaks after oxidation and the presence of a strong charge transfer band in the near-IR region. The implications of the indoline dye reactivity and fast hole mobility for solar cell devices are discussed.

Aggregation of cationic isothiouronium polythiophenes with alkoxy-spacers of different lengths at the 3-position of the thiophene ring was studied in solvents of different polarities. Hydrogen-bonding capacity was assessed by steady-state absorption and fluorescence spectroscopy, whereas the aggregation in aqueous solutions was studied by electron paramagnetic resonance spectroscopy, using paramagnetic probes of different polarities. The two polymers displayed similar features in respect to conformation, effect of cosolvents on aggregation, unstructured absorption–fluorescence spectra, Stokes shifts when aggregated, solvatochromic effect, and self-quenching concentration. However, these polymers also showed different specific interactions with water, Stokes shifts in water, effect of the solvent on the extent of dominant state of the S1 level, and also different inner cavities and hydrophobic–hydrophilic surface area in aqueous solution aggregates. Water maximized the difference between the polymers concerning the effect of specific increases in concentration, whereas the presence of 1,4-dioxane generated almost identical effects on both polymers.

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Cationic imidazolium-functionalized polythiophenes with single- or double-methylation of the imidazolium ring were used to study the impact of imidazolium-methylation on (i) the solution concentration-driven aggregation in the presence of paramagnetic probes with different ionic and hydrophobic constituents and (ii) their surface free energy (SFE) as spin-coated films deposited on plasma-activated glass. Electron paramagnetic resonance spectroscopy shows that the differences in film structuration between the polymers with different methylations originate from the early stages of aggregation. In the solid state, higher degree of imidazolium-methylation generates smaller values of total SFE, γ S , (by around 2 mN/m), which could be relevant in optoelectronic applications. Methylation also causes a decrease in the polar contribution of γ S (γS p ), suggesting that methylation decreases the polar nature of the imidazolium ring, probably due to the blocking of its H-bonding capabilities. The values of γ S obtained in the present work are similar to the values obtained for doped films of neutral conjugated polymers, such as polyaniline, poly(3-hexylthiophene), and polypyrrole. However, imidazolium-polythiophenes generate films with a larger predominance of the dispersive component of γ S (γS d ), probably due to the motion restriction in the ionic functionalities in a conjugated polyelectrolyte, in comparison to regular dopants. The presence of 1,4-dioxane increases γS p , especially, in the polymer with larger imidazolium-methylation (and therefore unable to interact through H-bonding), probably by a decrease of the imidazolium–glass interactions. Singly-methylated imidazolium polythiophenes have been applied as electrode selective (“buffer”) interlayers in conventional and inverted organic solar cells, improving their performance. However, clear structure–function guidelines are still needed for designing high-performance polythiophene-based interlayer materials. Therefore, the information reported in this work could be useful for such applications.