Noncovalent Bonding in d and f-Type Coordination Compounds and Lattices. A Case Study.

Using as example the [Fe(bpca)(μ-bpca)Gd(NO)]×4CHNO×CHOH system, where Hbpca=bis(2-pyridilcarbonyl)amine), we perform the analysis of bonding components inside the d and f coordination units and between molecular entities from crystal. Aside the nominal long-range interactions between molecular components of the crystal, we considered that the bonding inside the coordination units is also not a covalent regime. We performed Density Functional Theory (DFT) calculations, with plane-waves (PW), in band-structure mode, and with atom-centred bases, by molecular procedures.

MeNPs-PEDOT Composite-Based Detection Platforms for Epinephrine and Quercetin.

The development of low-cost, sensitive, and simple analytical tools for biomolecule detection in health status monitoring is nowadays a growing research topic. Sensing platforms integrating nanocomposite materials as recognition elements in the monitoring of various biomolecules and biomarkers are addressing this challenging objective. Herein, we have developed electrochemical sensing platforms by means of a novel fabrication procedure for biomolecule detection.

Insight into the interaction of quinizarin with SDS micelles - effects of additives.

Association behavior between quinizarin (1,4-dihydroxyanthraquinone), an analogue of the chromophore of anthracycline anticancer drugs and sodium dodecyl sulfate (SDS) micelles in the presence of glucose, NaCl and urea additives was studied using absorption spectroscopy and conductometric techniques. The spectral results indicate an increase of binding constant and partition coefficient values in the presence of glucose and NaCl whereas the addition of urea leads to a decrease of binding strength and quinizarin partitioning into SDS micelles. Thus, the rise of NaCl and glucose concentrations is favorable for the quinizarin distribution into SDS micelles.

Near-90° Switch in the Polar Axis of Dion-Jacobson Perovskites by Halide Substitution.

Ferroelectricity in two-dimensional hybrid (2D) organic-inorganic perovskites (HOIPs) can be engineered by tuning the chemical composition of the organic or inorganic components to lower the structural symmetry and order-disorder phase change. Less efforts are made toward understanding how the direction of the polar axis is affected by the chemical structure, which directly impacts the anisotropic charge order and nonlinear optical response. To date, the reported ferroelectric 2D Dion-Jacobson (DJ) [PbI] perovskites exhibit exclusively out-of-plane polarization.

Effect of SDS Micelles on Actinomycin D - DNA Complexes.

DNA thermal denaturation was evaluated as a measure of the effect of antitumor drug actinomycin D on the stability of the double helix and also the effect of SDS micelles on actinomycin D - DNA complexes. The results indicated that the melting temperature of DNA was dependent on drug concentration, increasing with actinomycin D concentration. High thermal stabilization (about 10 °C) of the DNA helix after the association with actinomycin D clearly demonstrates the intercalative binding mode.

The Density Functional Theory Account of Interplaying Long-Range Exchange and Dispersion Effects in Supramolecular Assemblies of Aromatic Hydrocarbons with Spin.

Aromatic hydrocarbons with fused benzene rings and regular triangular shapes, called -triangulenes according to the number of rings on one edge, form groundstates with -1 unpaired spins because of topological reasons. Here, we focus on methodological aspects emerging from the density functional theory (DFT) treatments of dimer models of the = 2 triangulene (called also phenalenyl), observing that it poses interesting new problems to the issue of long-range corrections. Namely, the interaction comprises simultaneous spincoupling and van der Waals effects, i.

Study of Quinizarin Interaction with SDS Micelles as a Model System for Biological Membranes.

Investigation of the interaction of quinizarin (Q), an analogue of the core unit of different anticancer drugs, with anionic SDS micelles has been performed by absorption and conductance measurements in 0.1 M phosphate buffer, pH 7.4 and over the temperature range of 298.

Atoms in Generalized Orbital Configurations: Towards Atom-Dedicated Density Functionals.

Deriving a practical formula for the atomic body with generalized shell occupations, we perform a detective analysis of the radial distribution in the exchange energy, hinting at ideas about new types of density functionals, dedicated to the specifics of the electronic structure of atoms, exploiting the intrinsic spherical symmetry.

Molecular and Supramolecular Interactions in Systems with Nitroxide-Based Radicals.

Nitroxide-based radicals, having the advantage of firm chemical stability, are usable as probes in the detection of nanoscale details in the chemical environment of various multi-component systems, based on subtle variations in their electron paramagnetic resonance spectra. We propose a systematic walk through the vast area of problems and inquires that are implied by the rationalization of solvent effects on the spectral parameters, by first-principle methods of structural chemistry. Our approach consists of using state-of-the-art procedures, like Density Functional Theory (DFT), on properly designed systems, kept at the border of idealization and chemical realism.

The Structural Details of Aspirin Molecules and Crystals.

We revisit, in the key of structural chemistry, one of the most known and important drugs: the aspirin. Although apparently simple, the factors determining the molecular structure and supramolecular association in crystals are not trivial. We addressed the problem from experimental and theoretical sides, considering issues from X-ray measurements and results of first-principle reconstruction of molecule and lattices by ab initio calculations.

Spectroscopic Investigation of the Interaction of the Anticancer Drug Mitoxantrone with Sodium Taurodeoxycholate (NaTDC) and Sodium Taurocholate (NaTC) Bile Salts.

The focus of the present work was to investigate the interaction of the anticancer drug mitoxantrone with two bile salts, sodium taurodeoxycholate (NaTDC) and sodium taurocholate (NaTC). Ultraviolet-visible (UV-Vis) absorption and electron paramagnetic resonance (EPR) spectroscopy were used to quantify the interaction and to obtain information on the location of mitoxantrone in bile salt micelles. The presence of submicellar concentrations of both bile salts induces mitoxantrone aggregation and the extent of drug aggregation in NaTDC is higher than in NaTC.

Mitoxantrone-Surfactant Interactions: A Physicochemical Overview.

Mitoxantrone is a synthetic anticancer drug used clinically in the treatment of different types of cancer. It was developed as a doxorubicin analogue in a program to find drugs with improved antitumor activity and decreased cardiotoxicity compared with the anthracyclines. As the cell membrane is the first barrier encountered by anticancer drugs before reaching the DNA sites inside the cells and as surfactant micelles are known as simple model systems for biological membranes, the drugs-surfactant interaction has been the subject of great research interest.