Synthesis, Crystal Structures and Magnetic Properties of Trinuclear {Ni2Ln} (LnIII = Dy, Ho) and {Ni2Y} Complexes with Schiff Base Ligands

The reaction of the Schiff base ligand o-OH-C6H4-CH=N-C(CH2OH)3, H4L, with Ni(O2CMe)2∙4H2O and lanthanide nitrate salts in a 4:2:1 ratio lead to the formation of the trinuclear complexes [Ni2Ln(H3L)4(O2CMe)2](NO3) (Ln = Dy (1), Ho (2), and Y (3)) which crystallize in the non-centrosymmetric space group Pna21. The complex cation consists of the three metal ions in an almost linear arrangement. The {Ni2Ln} moieties are bridged through two deprotonated Ophenolato groups from two different ligands. Each terminal NiII ion is bound to two ligands through their Ophenolato, the Nimino atoms and one of the protonated Oalkoxo groups in a distorted octahedral. The central lanthanide ion is coordinated to four Ophenolato oxygen from the four ligands, and four Ocarboxylato atoms from two acetates which are bound in the bidentate chelate mode, and the coordination polyhedron is biaugmented trigonal prism, which probably results in a non-centrosymmetric arrangement of the complexes in the lattice. The magnetic properties of 1–3 were studied and showed that 1 exhibits field induced slow magnetic relaxation.

Four mononuclear dysprosium complexes with neutral Schiff-base ligands: syntheses, crystal structures and slow magnetic relaxation behavior

Four mononuclear 9-coordinate Dy-based complexes, [Dy(HL1)2(NO3)3(CH3OH)] (1Dy), [Dy(HL2)2(NO3)3(H2O)] (2Dy), [Dy(HL3)3(NO3)3]·CH3CN (3Dy), [Dy(HL4)3(NO3)3] (4Dy), have been constructed by neutral Schiff-base ligands (1-[N-(4-R)aminomethylidene-2(1H)-naphthalenone, R=-Cl (HL1), -NO2 (HL2), -OCH3 (HL3), -I (HL4) )....

Synthesis, Characterization and Evaluation of Biological Activities of Sn(II) Complexes of Schiff Base Incorporating Sulpha Drugs

In this study, we report synthesis, characterization and biological activities of four sulpha drug based Schiff base ligands and their Sn(II) complexes. The Schiff bases and their Sn(II) complexes have been synthesized by traditional methods and characterized by the spectral techniques IR, NMR (1H and 13C), mass and TGA-DTA. Newly synthesized Schiff bases (L1-L4) and their Sn(II) complexes (C-1 to C-4) have been screened for antibacterial activity against bacterial strains S. aureus, S. pyogenus, E. coli, P. aeruginosa and antifungal activity against fungal strains C. albicans, A. niger, A. clavatus using broth micro dilution method. Best antimicrobial activity was shown by C-3 complex against E. coli (MIC, 50.0 µg/mL) and A. niger microbial strains (MIC, 100 µg/mL). Moreover, antimalarial activity against plasmodium falciparum was also studied. Complex C-3 was found to be more active against parasite P. falciparum (IC50, 0.04 µg/mL). Results showed that dichloride tin complexes are more active with respect to their corresponding Schiff base ligands.

Synthesizing, Structuring, and Characterizing Bioactivities of .Cr(III), La(III), and Ce(III) .Complexes with Nitrogen, Oxygen .and Sulpher donor bidentate Schiff base ligands

Two Schiff bases, namely, 3-(benzylidene amino) -2-thioxo-6-methyl 2,5-dihydropyrimidine-4(3H)-one (LS])and 3-(benzylidene amino)-6-methyl pyrimidine 4(3H, 5H)-dione(LA)as chelating ligands), were used to prepare some complexes of Cr(III), La(III), and Ce(III)] ions. Standard physico-chemical procedures including metal analysis M%, element microanalysis (C.H.N.S) , magnetic susceptibility, conductometric measurements, FT-IR and UV-visible Spectra were used to identify Metal (III) complexes and Schiff bases (LS) and (LA). According to findings, a [Cr(III) complex] showed six coordinated octahedral geometry, while [La(III), and Ce(III) complexes]were structured with coordination number seven. Schiff's bases and mineral complexes were examined in vitro to investigate potential inhibition against Gram-positive bacteria such as Pseudonomous aerugionosa and Gram-negative bacteria such as Staphylococcus aureus. The low concentration for inhibition has been also determined by studying the minimal inhibitory concentrations MIC .Antibiotics (Ampicillin, Amoxicillin) have been chosen to contrast their activity. Furthermore, Anti-fungal activity against two types of fungi ʺAspergillus flavusʺ and ʺPenicillum Spp.ʺ was studied for these compounds. The results of the antibacterial activity were better compared to the standard drugs.

Synthesis, Characterization, X-Ray Crystal Structures and Antibacterial Activity of Cobalt(III) Complexes Derived from 5-Bromo-2-((2-(phenylamino) ethylimino)methyl)phenol

Two new and similar cobalt(III) complexes, [CoL2] · NO3 (1) and [CoL2] · Cl (2), where L is 5-bromo-2-((2-(phenylamino) ethylimino)methyl)phenolate, have been synthesized and characterized by IR and UV-Vis spectra. Structures of the complexes were confirmed by single crystal X-ray determination. The Co atoms in the complexes are in octahedral coordination, with the donor atoms come from the two Schiff base ligands, viz. phenolate oxygen, and imino and amino nitrogen. The anions of the cobalt salts crystallized as counteranions in the complexes. The complexes were assayed for antibacterial activities by MTT method.

Electronic Structure of Two New Bis-Schiff Base Ligands using DFT Method

Two bis-Schiff Bases 1 and 2 are ligands that can coordinate with manganese metal to form stable complexes and have biological activity. Thermodynamic parameters, HOMO-LUMO energy levels and FTIR spectra of two ligands have been computed using B3LYP/6-311++G(d,p) functional of the DFT calculations. Both ligands are favored thermodynamically, and the ligand 1 has been shown to be more stable than ligand 2. The Polarizability values of two ligands have been investigated. The results refer that ligand 2 interacts earlier than ligand 1 to the metal ion. The FTIR spectra of two ligands have been evaluated. All results show the good agreement between the theoretical and experimental data.