Synthesis, Characterization and Antibacterial Activity of New Complexes of Some Lanthanide Ions with 15-Crown-5 and 18-Crown-6

Abstract

Complexes of some lanthanide picrates (Ln 3+ = Pr 3+, Nd 3+ and Dy 3+ ) with 15-crown-5 and 18-crown-6 were synthesized and characterized by elemental analysis, ICP-AES, FTIR, 1 H-NMR, 13C-NMR and UV-Visible spectrophotometric methods, thermal analysis (TGA & DTG), magnetic susceptibility , molar conductance and melting points. Also an in-vitro study on pathogenic gram positive (Staphylococcus aureus) and pathogenic gram negative bacteria (Escherichia coli, Salmonella and pseudomonas aeruginosa) was performed and the results were compared to those of a broad spectrum antibiotic (Chloramphinicol). 3+ and Dy 3+ were coordinated with two 15-crown-5 ligands and one picrate anion through its phenolic oxygen and the oxygen of it's ortho nitro group, except for Pr 3+ which was coordinated with only one 15-crown-5 ligand leaving three picrate anions as counter ions. In 18-crown-6 complexes both Pr 3+ and Nd 3+ were coordinated with one 18-crown-6 ligand leaving all the three picrate anions as counter ions outside the coordination sphere, except for the Dy 3+ complex which was coordinated with one 18-crown-6 ligand and one picrate anion.

The Evaluation of F-F Spectra of Some ER (Iii) Ternary Complexes Containing Crown Ethers and Amino Acids & Computation of Spectral Parameters Using the Spectra

“…The metal-ligand stoichiometry affects the oscillator strength; higher the value of oscillator strength, higher will be complexation and covalency. This is in an agreement with earlier findings [15][16][17][18] V. Table-3 Computed values of Judd-OfeltParameter (T λ ) for Er(III) complexes of CE, CB or CD (L 1 ) with AL, GY or AR (L 2 ), respectively, in 1:3:2 stoichiometry.…”

Electrochemical Determination of Neurotransmitters at Crown Ether Modified Carbon Nanotube Composite: Application for Sub‐nano‐sensing of Serotonin in Human Serum

“…Based on IR analysis of (CNTs‐ILC)/Crown and 18‐crown‐6 spectra (Figures A & B), the band of the (C−O−C) stretching vibration which is the most important band of the 18‐crown‐6 is observed in (CNTs‐ILC)/Crown spectrum as strong peak at 1107.9 cm −1 Figure A. This peak is assigned to the ether functional group (C−O−C) as it lies in the range 1110–1250 cm −1 . It indicates that crown ether was successfully deposited onto the surface of the CNTs‐ILC.…”

Highly Conductive Crown Ether/Ionic Liquid Crystal-Carbon Nanotubes Composite Based Electrochemical Sensor for Chiral Recognition of Tyrosine Enantiomers

“…1A and 1B), which was assigned to the ether functional group (C-O-C) stretching vibration band. 49 Other peaks appeared at 1469 cm −1 and 1737 cm −1 for MWCNTs vibrational modes 50 and at 841 cm −1 and 558 cm −1 for C-N stretching vibrations of piperidinium core of ILC. 29 Scanning electron microscopy was used for examining the morphology of GC /CNT+ILC surface (Figure 1C), where a dense compact network structure of the (CNT+ILC) composite surface was observed.…”