The electronic effects induced by the geometry of the 1,2-diimine bridge control the Lewis acidic character in a series of Zn ^II Shiff-base complexes.

Efficient water-dispersible and biocompatible nanohybrids for red-light triggerable photothermal and drug release effects.

New dyes PY-4N and PY-3N showed PCE values of 21.29% and 16.52%. Phosphonate analogs, exhibited the highest energy adsorption on TiO₂. Results suggest a potential use of these dyes as standalone sensitizers or co-sensitizers in PV applications.

The structural and dynamical properties of 40-mer of thermo-responsive polymer PNIPAM covalently bound to different surfaces have been studied, at different temperatures, by means of molecular dynamics simulations. Evolution of the radius of gyration, R_g, of the polymer chain and radial distribution functions (RDFs) calculated for the carbon atoms of the PNIPAM backbone with water oxygens and for the hydrogen atom of the amide groups with water oxygens indicate that functionalized surfaces affect the coil-to-globule transition of PNIPAM, by means of electrostatic interactions, increasing the lower critical solution temperature (LCST) of the polymer. Such interactions, mainly represented by a H-bond, hinder the transition in the globular form while hydrophobic groups on the surface, such as –OCH₃, contribute to the globular collapse. A significant alteration in the arrangement of water molecules around the polymer is testified by: (i) the absence of the second peak in the RDF between the C atoms of the PNIPAM backbone and the O atoms of water at the same temperature at which the radius of gyration decreases; (ii) the height of both the first and the second peak of the RDF between the H atom of the amide groups and water O atoms decreases when the temperature increases above the LCST. Finally, the H-bond autocorrelation function indicates that: (i) hydrogen bonds between the bound-to-surface PNIPAM acceptor groups (OC) and the H atoms of water molecules are less persistent than H-bonds formed between the free PNIPAM acceptor groups and water; (ii) H-bonds between the PNIPAM acceptor groups and hydroxyl groups on the quartz surface are longer lived than those formed on graphene oxide.

In this study, graphene oxide (GO) and reduced-thiolated GO (rGOSH) were used as 2D substrate to fabricate nanocomposites with nanoparticles of gold nanospheres (AuNS) or nanorods (AuNR), via in situ reduction of the metal salt precursor and seed-mediated growth processes. The plasmonic sensing capability of the gold-decorated nanosheets were scrutinized by UV-visible (UV-VIS) spectroscopy. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analyses (TGA), and atomic force microscopy (AFM) were performed in order to prove the actual reduction that occurred concomitantly with the thiolation of GO, the increase in the hydrophobic character as well as the size, and preferential gathering of the gold nanoparticles onto the nanosheet substrates, respectively. Moreover, the theoretical electronic and infrared absorption (UV-VIS and IR) spectra were calculated within a time-dependent approach of density functional theory (DFT). Eventually, in vitro cellular experiments on human neuroblastoma cells (SH-SY5Y line) were carried out in order to evaluate the nanotoxicity of the nanocomposites by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction (MTT) colorimetric assay. Results pointed out the promising potential of these hybrids as plasmonic theranostic platforms with different hydrophilic or hydrophobic features as well as cytotoxic effects against cancer cells.

Structure and electronic properties of two unusual boron clusters obtained by fusion of borozene rings have been studied by means of first principles calculations based on the generalized-gradient approximation of the density functional theory. Moreover, a semiempirical tight-binding model has been appropriately calibrated for transport calculations on these clusters. Results show that the pure boron clusters are topologically planar and characterized by (3c–2e) bonds, which can explain, together with the aromaticity (estimated by means of NICS), the remarkable cohesive energy values obtained. Such feature makes these systems competitive with the most stable boron clusters to date. The energy gap values indicate that these clusters possess a semiconducting character, while when the larger system is considered, zero-values of the density of states are found exclusively within the HOMO–LUMO gap. Electron transport calculations within the Landauer formalism confirm these indications, showing semiconductor-like low bias differential conductance for these structures. Differences and similarities with carbon clusters are highlighted in the discussion.