Synthesis, crystal structure and Hirshfeld surface analysis of (2Z,2'E)-2,2'-(3-meth-oxy-3-phenylpropane-1,2-diyl-idene)bis-(hydrazine-1-carbo-thioamide) di-methyl-formamide monosolvate

The overall mol-ecular configuration of the title compound, C12H16N6OS2·C3H7NO, is stabilized in the solid state by intra-molecular C-H⋯N, C-H⋯O, N-H⋯N and N-H⋯O inter-actions, forming S(5) ring motifs. In the crystal, mol-ecules are linked to each other and solvent di-methyl-formamide mol-ecules by N-H⋯S, N-H⋯O, C-H⋯O and C-H⋯S hydrogen bonds, forming a three dimensional network. The phenyl ring of the title compound is disordered over two sites with an occupancy ratio of 0.57 (4):0.43 (4). A Hirshfeld surface analysis was performed to qu-antify the contributions of the different inter-molecular inter-actions, indicating that the most important contributions to the crystal packing are from H⋯H (38.7%), S⋯H / H⋯S (24.0%), C⋯H / H⋯C (18.5%) and N⋯H / H⋯N (9.8%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-(4-chlorophenyl)-4-(dimethoxymethyl)-5-phenyl-1,3-thiazole

In the title compound, the dihedral angles between the thia­zole ring and its attached chloro­phenyl and phenyl rings are 13.12 (14) and 43.79 (14)°, respectively.

In the title compound, C₁₈H₁₆ClNO₂S, the thia­zole ring subtends dihedral angles of 13.12 (14) and 43.79 (14) ° with the attached chloro­phenyl and phenyl rings, respectively. In the crystal, C—H⋯π inter­actions link the mol­ecules, forming a three-dimensional network. The roles of the various inter­molecular inter­actions were clarified by Hirshfeld surface analysis, which reveals that the most important contributions to the crystal packing are from H⋯H (39.2%), H⋯C/C⋯H (25.2%), Cl⋯H/H⋯Cl (11.4%) and O⋯H/H⋯O (8.0%) contacts.

Novel Fe-Pd/SiO2 catalytic materials for degradation of chlorinated organic compounds in water

Novel reactive materials for catalytic degradation of chlorinated organic compounds in water at ambient conditions have been prepared on the basis of silica-supported Pd-Fe nanoparticles. Nanoscale Fe-Pd particles were synthesized inside porous silica supports using (NH4)3[Fe(C2O4)3] and [Pd(NH3)4]Cl2 or Pd acetate as reaction precursors. According to temperature programmed reduction (TPR) studies, Pd introduction decreased the reduction temperature of the supported Fen+ species and nearly complete reduction with H2 was observed at 400 °C. The successful surface loading with Pd was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Characterization of the samples by X-ray diffraction (XRD) and X-ray absorption near-edge structure + extended X-ray absorption fine structure (XANES + EXAFS) verified the presence of highly dispersed Pd0, Pdx Fe1–x and Fe0 phases. Reduction of the supported precursors in hydrogen resulted in materials that were highly active in perchloroethene (PCE) degradation and 2-chlorobiphenyl (2-ClBP) dechlorination. It was found that highly dispersed amorphous Fe-Pd bimetallic nanoparticles on silica support showed superior catalytic activity against PCE dechlorination in comparison to the free-standing Fe-Pd nanoparticles. For the samples with the same Fe content, the conversion of chlorinated organics as well as the stability increased with the Pd loading, e.g., the most effective degradation of PCEs and 2-ClBP was achieved at a Pd loading of 2.3–3.2 wt. %.

Pd-Fe nanoparticles stabilized by chitosan derivatives for perchloroethene dechlorination

A series of chitosan-stabilized Pd-NZVI (nano-zero-valent-iron) catalysts for dechlorination with variation in their composition and in the nature of the polymer has been prepared. The synthesis procedures and palladium and chitosan contents were optimized. It was demonstrated by the XPS method that Fe and Pd in Fe-Pd/chitosan samples exist in the metallic state. The positive shift of the binding energy as compared with the bulk metal shows that the iron metal in the surface layers exists as very small nanoparticles. The prepared materials were characterized also by the XAS method. The presence of O and N atoms in the first coordination shell of the central Fe atom in the Fe-Pd/chitosan samples certifies the binding of the Fe metal particles with the chitosan surface via OH and NH(2) groups. The samples are characterized by the high stability of the nanoparticles as compared to unstabilized Pd-NZVI. The materials were tested to evaluate their catalytic activity in the perchloroethene (PCE) dechlorination reaction. Some samples of chitosan-stabilized Pd-NZVI revealed a good performance in PCE degradation as compared to unstabilized Pd-NZVI.

[Sorption of phthalocyanine dye by erythrocyte membranes in buffered solutions of different tonicities]

The sorption of nonpenetrating vital phthalocyanine dye--Heliogen Blue (HB) into the cells was studied on the human red cells incubated in hypertonic, isotonic and hypotonic solutions. The alteration in the outer membrane surface was detected using the monomer-dimer ratio (M/D) deduced from the absorbtion spectra of the sorbed dye, and the concentration (C) of the dye in membrane. The decrease in M/D and C was found in hypotonic and hypertonic conditions, resp. The increase in the number of binding sites caused by conformational changes in membrane is discussed.

[Use of phthalocyanine dye in spectroscopic research on the erythrocyte membrane with altered peripheral protein composition]

The absorption spectra of Heliogen Blue (HB) dye were registered on stained ghosts of human red blood cells. The monomer-dimer ratio (M/D) was used as a characteristic of the absorbtion band of HB in the red spectral region. It is determined that incubation of ghosts in the sodium hydrate solution (pH 12) leads to changes in the visible HB spectrum. When the ghosts are stained after NaOH treatment, the M/D value decreases. When stained ghosts are treated with NaOH, the M/D value increases. The decrease in M/D value is due to the increase in HB sorption capacity of the modified membranes; the increase in M/D value is due to the removal of proteins sorbing HB. The appearance of additional sites for HB sorption and the decrease in M/D value in the HB spectrum may be explained by a conformational alteration of the integral proteins or by substitution of some molecules of the peripheral proteins for the HB molecules.

[Spectrophotometric study of intact and trypsin-treated erythrocyte membranes using a phthalocyanine dye]

The sorption of vital phthalocyanine dye--Heliogen Blue (HB)--by red cells and their ghosts after trypsin treatment has been studied. The structural alteration in the outer and inner surface of the membrane was detected using the monomer-dimer ratio (M/D) deduced from the absorption spectra of the sorbed dye. The trypsin treatment causes the increase in the M/D ratio. It is greater (44%) when both the membrane surfaces are exposed to trypsin (unsealed ghosts), and is only 19% when the whole erythrocytes are treated. The similar alteration (M/D increased by 18%) is obtained for red blood cells stained after incubation in the isotonic buffer solution at 37 degrees C. Recent findings show a good agreement with our previous data on the influence of changes in the membrane surface on the value of the M/D ratio. A possibility of using HB in determination of structural changes of a native membrane is discussed.

[Spectrophotometric study of the surface of human erythrocytes and their ghosts by using a phthalocyanine dye]

Human intact erythrocytes and their ghosts (resealed and unresealed) were stained by the vital dye Heliogen Blue, which does not penetrate the cell being only sorbed by its membrane. The absorption spectra of the sorbed dye were examined. On the external surface of the membrane, the molecular (monomer) state of dye sorption is revealed, whereas on the interior side the dye sorption is mostly in the polymolecular (dimer) state. The differences in staining can be evaluated by the monomer-dimer ratio (M/D), which may be used for comparison between the sorption characteristics of membrane preparations.