Lanthanide complexes of potentially heptadentate Schiff base ligands

1982 ◽  
Vol 60 (5) ◽  
pp. 667-672 ◽  
Author(s):  
Elmer C. Alyea ◽  
Abdul Malek ◽  
Angelos E. Vougioukas

The potentially heptadentate trianionic Schiff base ligands derived from tris(2-aminoethyl)amine and 3 mol of (substituted) salicylaldehyde react with lanthanide metal nitrates to form neutral 1:1 compounds of formula Ln(X-Saltren). Physicochemical measurements are described for the following complexes: Ln = La, Pr, Nd, Eu, Gd, Dy, Ho, Yb, X = 3,5-Cl2; Ln = La, X = 5-Cl and 5-NO2; and the analogous complexes, M = Sc, Y, Co, X = 3,5-Cl2. Discussion of the spectroscopic data focuses on far infrared ν(Ln—O) and ν(Ln—N) bands, 1H nmr pseudocontact shifts and hypersensitive f–f transitions.

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 728
Author(s):  
Alberto Aragón-Muriel ◽  
Yamil Liscano ◽  
Yulieth Upegui ◽  
Sara M. Robledo ◽  
María Teresa Ramírez-Apan ◽  
...  

Metal-based drugs, including lanthanide complexes, have been extremely effective in clinical treatments against various diseases and have raised major interest in recent decades. Hence, in this work, a series of lanthanum (III) and cerium (III) complexes, including Schiff base ligands derived from (1H-benzimidazol-2-yl)aniline, salicylaldehyde, and 2,4-dihydroxybenzaldehyde were synthesized and characterized using different spectroscopic methods. Besides their cytotoxic activities, they were examined in human U-937 cells, primate kidney non-cancerous COS-7, and six other, different human tumor cell lines: U251, PC-3, K562, HCT-15, MCF-7, and SK-LU-1. In addition, the synthesized compounds were screened for in vitro antiparasitic activity against Leishmania braziliensis, Plasmodium falciparum, and Trypanosoma cruzi. Additionally, antibacterial activities were examined against two Gram-positive strains (S. aureus ATCC® 25923, L. monocytogenes ATCC® 19115) and two Gram-negative strains (E. coli ATCC® 25922, P. aeruginosa ATCC® 27583) using the microdilution method. The lanthanide complexes generally exhibited increased biological activity compared with the free Schiff base ligands. Interactions between the tested compounds and model membranes were examined using differential scanning calorimetry (DSC), and interactions with calf thymus DNA (CT-DNA) were investigated by ultraviolet (UV) absorption. Molecular docking studies were performed using leishmanin (1LML), cruzain (4PI3), P. falciparum alpha-tubulin (GenBank sequence CAA34101 [453 aa]), and S.aureus penicillin-binding protein 2a (PBP2A; 5M18) as the protein receptors. The results lead to the conclusion that the synthesized compounds exhibited a notable effect on model membranes imitating mammalian and bacterial membranes and rolled along DNA strands through groove interactions. Interactions between the compounds and studied receptors depended primarily on ligand structures in the molecular docking study.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
K. R. Joshi ◽  
A. J. Rojivadiya ◽  
J. H. Pandya

Two new series of copper(II) and nickel(II) complexes with two new Schiff base ligands 2-((2,4-dimethylphenylimino)methyl)-6-methoxy-4-nitrophenol and 2-((3,4-difluorophenylimino)methyl)-6-methoxy-4-nitrophenol have been prepared. The Schiff base ligands were synthesized by the condensation of 2-hydroxy-3-methoxy-5-nitrobenzaldehyde with 2,4-dimethylaniline or 3,4-difluoroaniline. The ligands and their metal complexes have been characterized by IR, 1H NMR, mass and electronic spectra and TG analysis. The Schiff base ligands and their metal complexes were tested for antimicrobial activity against Gram positive bacteria Staphylococcus aureus, and Streptococcus pyogenes and Gram negative bacteria Escherichia coli, and Pseudomonas aeruginosa and fungus Candida albicans, Aspergillus niger, and Aspergillus clavatus using Broth Dilution Method.


2010 ◽  
Vol 37 (11) ◽  
pp. 1393-1410 ◽  
Author(s):  
Nandiraju V.S. Rao ◽  
Trirup D. Choudhury ◽  
Rahul Deb ◽  
Manoj K. Paul ◽  
Thatavarthi R. Rao ◽  
...  

2010 ◽  
Vol 36 (6) ◽  
pp. 468-471 ◽  
Author(s):  
T. A. Babushkina ◽  
T. P. Klimova ◽  
L. D. Kvacheva ◽  
Yu. A. Peregudova

2011 ◽  
Vol 8 (s1) ◽  
pp. S245-S252 ◽  
Author(s):  
Praveen S. Mane ◽  
Sanjiv M. Salunke ◽  
Balagi S. More

The solid complexes of Cu(II), Ni(II), Co(II), Mn(II) and Fe(III) with Schiff base ligands derived from heterocyclic compounds 3-acetyl-6-methyl-(2H)-pyran-2,4(3H)-dione (Dehydroacetic acid) ando-chloroaniline were synthesized and characterized by elemental analysis, conductance, magnetic, thermal, UV-Vis and1H-NMR spectroscopy. The ligand field parameters have been evaluated for Cu(II), Ni(II), Co(II), Mn(II) and Fe(III) complexes which suggest an octahedral geometry for each of them. The magnetic moment and spectral data suggest the dimeric nature of Mn(II) complexes with octahedral geometry. The fungicidal activities of the ligands and their metal complexes have been screened in vitro againstAspergillus nigerand the percentage inhibition of the metal complexes is found to be increased considerably then that of their corresponding ligands and the order is Cu>Ni>Fe>Mn>Co.


1997 ◽  
Vol 4 (2) ◽  
pp. 65-68 ◽  
Author(s):  
Zahid H. Chohan ◽  
Syed K. A. Sherazi

Metal(II) complexes of hydrazine derived Schiff-base ligands of the type M(L)2Cl2 where M = Co, Cu, Ni and Zn and L = L1 and L2 have been prepared and characterised by molar conductance, magnetic moment, elemental analysis and electronic, IR, H-NMR and C13 spectral data.The different modes of chelation of the ligands and their comparative biological properties against different bacterial species are reported.


2010 ◽  
Vol 46 (17) ◽  
pp. 2929 ◽  
Author(s):  
Dong-Ping Li ◽  
Tian-Wei Wang ◽  
Cheng-Hui Li ◽  
Dong-Sheng Liu ◽  
Yi-Zhi Li ◽  
...  

2012 ◽  
Vol 554-556 ◽  
pp. 736-740 ◽  
Author(s):  
Amalina Mohd Tajuddin ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Wan Nazihah Wan Ibrahim ◽  
Hoong Kun Fun

The syntheses, physico-chemical and spectroscopic characterization of ovan-type Schiff-base ligands (L1, L2) and their novel mononuclear Pd(II) complexes (PdL1, PdL2) are reported herein. Elemental analysis, FT-IR,1H NMR as well as magnetic susceptibility measurements characterised the compounds. The catalytic potential of the Pd(II) complexes for Heck coupling reaction were investigated and monitored using GC. It was observed that both Pd(II) complexes displayed properties of good catalysts for the reaction, indicated by 100% conversion of the starting materials to the subtituted alkene product after 6 hours of reaction time at 100°C in inert conditions. The catalytic activity was compared with the reaction without Pd(II) complexes.


Sign in / Sign up

Export Citation Format

Share Document