Physicochemical Studies on Some Metal Chelates of Cyclodiphosphazane and Thiourea Monophosphazene Derivatives

Abstract

The interaction of Cr(III), Mn(II), and Fe(III) ions with cyclodiphosphazane and thiourea monophosphazene derivatives was followed potentiometrically with the aim of determination of stability constants of (metal : ligand) 1:1 and 1:2 binary, and 1:1:1 ternary chelates at 25The stability of the complexes of both ligands was found to be Fe (III) > Mn(II) < Cr(III). The concentration distribution of the species formed in solution was evaluated. Binary and ternary solid complexes were prepared with the purpose of structural characterization using elemental analyses, molar conductance, IR, 1 HNMR and electronic spectra and thermogravimetric analysis. The data show that the ligands behave as neutral bidentate ligands, forming neutral chelates of monomeric nature.

Metal Complexes of Phosphorus Compounds Including Indigoid Structure: Synthesis, Characterization, and Biological Study

“…The precipitated solid complexes were filtered, washed several times with ethanol followed by diethylether, and dried in a vacuum desiccator over anhydrous calcium chloride. All metal complexes (1)(2)(3)(4)(5) are received as powder, stable in air, insoluble in common organic solvents but soluble in DMF and DMSO, and give elemental analysis consistent with the proposed structures. Their elemental analysis and some physicochemical characteristic data are collected in Table II …”

“…The IR spectra of metal complexes (Table IV) show that the stretching vibration band ν(NH) of heterocyclic ring (which in the free ligand, H 2 L 1 at 3300 cm −1 ) disappeared in the spectra of all metal complexes (1)(2)(3)(4)(5) indicating the deprotonation of this group as a result of complexation with metal ions. The strong absorption band appearing in the IR spectrum of the free ligand H 2 L 1 at 1628 cm −1 assigned to Downloaded by [Northeastern University] at 06:08 18 November 2014 …”

“…The cyclodiphosph(V)azane ligand (H 2 L 1 ) and its metal complexes (1)(2)(3)(4)(5) Pseudomonas phaseolicola (GSPB 2828) and Pseudomonas fluorescens (S 97) as Gram-negative bacteria, and the fungi Fusarium oxysporum, Aspergillus fumigatus, and Candida albicans. The antibiotics Cephalothin, Chloramphencol, and Cycloheximide were used as standard references for Gram-positive bacteria, Gram-negative bacteria, and fungi, respectively, using the agar-disc diffusion technique 22 described below:…”

“…1,2 Interest in the chemistry of phosphorus-containing heterocyclic compounds is linked with their participation in many biochemical processes, with their use as therapeutic preparations and agents for plant protection, and with use in organic synthesis, metal complex catalysis, and other areas. 3 Over the last decade, the ligands based on the cyclodiphosph(III or V)azane framework have been studied because of their ability to coordinate with main group and transition metals.…”