Synthesis, spectral and sol-gel behavior of mixed ligand complexes of titanium(IV) with oxygen, nitrogen and sulfur donor ligands

A new route to synthesize nano-sized Ti(IV) mixed ligand complexes have been investigated by the reaction of titanium(IV) chloride with ammonium salts of dithiophosphate and 3(2'-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolines. The resultant complex is then treated with H2S gas to get sulfur bridged dimer of Ti(IV) complex, a precursor of TiS2. The morphology of the complexes was studied by employing XRD which shows that all the complexes are amorphous solid. Molecular weight measurements, elemental analysis in conjugation with spectroscopic (IR, 1H NMR, 13C NMR and 31P NMR) studies revealed the dimeric nature of the complexes in which pyrazoline and dithiophosphate are bidentate. Scanning electron microscopic image and XRD indicate that the particles are in the nano range (50 nm). Putting all the facts together, coordination number six is proposed for titanium with octahedral geometry. KEY WORDS: Titanium(IV), Dithiophosphate, Pyrazoline, Nano-sized, Sol-gel, Mixed ligand complexes Bull. Chem. Soc. Ethiop. 2021, 35(1), 61-76. DOI: https://dx.doi.org/10.4314/bcse.v35i1.5

Adsorption of selected azo dyes from an aqueous solution by activated carbon derived from Monotheca buxifolia waste seeds

In this study, activated carbon derived from Monotheca buxifolia waste seeds was used for the adsorptive removal of a number of selected azo dyes such as Eriochrome Black T (EBT), Remazol brilliant blue (RBB), Remazol yellow (RY) and Remazol brilliant orange (RBO) from an aqueous solution by changing the initial dye concentration, adsorbent dosage, solution pH, contact time and temperature. A Fourier transform infrared spectroscopic analysis of the activated carbon showed the existence of hydroxyls, methyl, methylene, carbonyls, alkane and alkenes groups while the scanning electron microscopic image displayed the gradual formation of cavities and open pores on the surface. The results showed that as the amount of the adsorbent and the shaking time were increased, the removal percentage of the dye increased accordingly. Higher adsorption percentages were observed at a lower dye concentration and temperature in an acidic media at a pH range (1–5). The investigated data were evaluated with the Langmuir and Freundlich adsorption models. The maximum adsorption capacities obtained from the Langmuir model were 112.36, 96.34, 97.65 and 90.91 mg/g for EBT, RBB, RY and RBO, respectively. The results indicated that the electrostatic interaction was the main cause of the adsorption of these anionic azo dyes on the surface of the activated carbon.

Preparation of Articular Cartilage for Scanning Electron Microscopy

The relationship between tissue preparation and a scanning electron microscopic image is still somewhat nebulous. For purposes of answering comments about our observations of articular cartilage, we decided to prepare tissue samples from one area of a femoral condyle, obtained at surgery, in several ways. As a result of this investigation we hoped to find the best way to prepare articular cartilage for maximal visual detail and subsequently standardize our procedures for a comparative study of normal and arthritic cartilage.The samples were fixed as follows: (1) no fixative; (2) 2% glutaraldehyde buffered with cacodylate, pH 7.4; (3) 10% buffered formalin; (4) 0.1% glutaraldehyde in Ringer's; and (5) 1% glutaraldehyde in Ringer's.

Leukemic Reticuloendotheliosis

The anatomical and functional features of the hairy cells of leukemic reticuloendothelisis were investigated by time lapse cinematography; phytohemagglutinin stimulation; adherence to siliconized surfaces; a variety of cytochemical methods; and phase, transmission, and scanning electron microscopy. The scanning electron microscopic image supports the morphologic evidence for a relationship between the hairy and the reticular cells.