Modern spectroscopic techniques in the characterization of Schiff base macrocyclic ligand and its complexes with transition metals

Author(s):  
Sulekh Chandra ◽  
Lokesh Kumar Gupta
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Hossein Naeimi ◽  
Mohsen Moradian

Synthesis and characterization of some new Schiff base ligands derived from various diamines and nitrosalicylaldehyde and their complexes of Ni(II) and Cu(II) are reported. Several spectral techniques such as UV-Vis, FT-IR, and NMR spectra were used to identify the chemical structures of the reported ligands and their complexes. The ligands are found to be bound to the metal atom through the oxygen atoms of the hydroxyl groups and nitrogen atoms of imine groups, which is also supported by spectroscopic techniques. The results obtained by FT-IR and NMR showed that the Schiff base complexes of transition metal (II) have square-planar geometry.


2012 ◽  
Vol 36 (1) ◽  
pp. 89-96
Author(s):  
Md Mahbubul Alam ◽  
Faisal Ahmed ◽  
Rockshana Begum ◽  
Mizanur Rahman ◽  
Iqbal Ahmed Siddiquey ◽  
...  

The cyclic (2+2) template condensation of pyridine-2,6-dicarboxaldehyde with 1,2-Bis(2- aminoethoxy) ethane using Pb(SCN)2 gave dinuclear lead (II) complex, Pb2L1(SCN)4 where L1 is a tetra-Schiff-base macrocycle. The transmetallation treatment of Pb2L1(SCN)4 with Cu(ClO4)2.6H2O yield the complex, [Cu2L1(SCN)3(ClO4)] which has been characterized by elemental analysis, IR, ESI-MS spectroscopy and X-ray crystallography. On the basis of spectral data, different geometry of Cu2+ has been suggested. DOI: http://dx.doi.org/10.3329/jbas.v36i1.10924 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 89-96, 2012


2021 ◽  
Vol 7 (4) ◽  
pp. 748-750
Author(s):  
S. Tihile Mangesh ◽  
N. Chaudhari Gajanan

The novel transition metal ion complexes were synthesized by refluxing the ethanolic solutions of metal acetates with Schiff base in 1:2 ratios. The structure and characterization of synthesized complexes of Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) with Schiff base (E)-2-((7H-purin-6-ylimino)methyl)phenol were elucidated by using 1H NMR, FT-IR and UV-Visible spectroscopic techniques. The synthesized compounds were also been screened against gram positive and gram-negative bacteria. The novel compounds were further carried out for the study of magnetic susceptibility.


2004 ◽  
Vol 82 (3) ◽  
pp. 437-447 ◽  
Author(s):  
Carlos Lodeiro ◽  
Rufina Bastida ◽  
Emilia Bértolo ◽  
Adolfo Rodríguez

Reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and N,N-bis(3-aminopropyl)methylamine or tris(2-aminoethyl)amine has been used as the starting point for the synthesis of seven oxa-aza macrocyclic ligands, five of them never reported previously. They all feature different pendant arms, which provide a wide range of coordination possibilities. The Schiff base macrocycles L1 and L4 and their reduced ligands L2 and L5 are derived from 2,6-bis(2-formylphenoxymethyl)pyridine and tris(2-aminoethyl)amine or N,N-bis(3-aminopropyl)methylamine, respectively. The reaction of L1 with salicylaldehyde forms L3, which features an imine bond in the pendant arm. The ligand L5 has been the precursor for the pendant-armed L6 and L7, by alkylation of the free NH groups with methyl-imidazole or methyl-indole. By a template or a nontemplate approach, we have synthesized different mono- and dinuclear complexes with Y(III), Ln(III), Zn(II), and Cd(II) cations. Both the free macrocyclic ligands and their corresponding metal complexes have been characterized by microanalysis, IR, UV–vis, 1H and 13C NMR spectroscopy, FAB mass spectrometry, MS electrospray, and conductivity measurements.Key words: Schiff-base macrocycle, template synthesis, macrocyclic ligand complexes, lanthanide(III) complexes.


2021 ◽  
Vol 12 (2) ◽  
pp. 1803-1813

The effective conjugation of electrons in aromatic Schiff bases has been utilized as an electrochemical sensor in forensic, pharmaceutical and environmental applications. The use of the Schiff base enhances the sensitivity and selectivity of the sensor. In this study, p-cyano Schiff base derived from 4-(4-aminostyryl)benzonitrile and three different aldehydes were synthesized. The spectroscopic techniques via Fourier transform-infrared spectroscopy (FT-IR), Uv-Vis spectrophotometry and Nuclear Magnetic Resonance (NMR) of 1H and 13C were used for structural elucidation resulted compounds. The targeted p-cyano Schiff base showed a clear imine (C=N) stretching vibration band at 1681-1708 cm-1, n→π* electronic transition at 355-360 nm in UV-Vis and a singlet: 8.34-8.39 ppm and 118.07-119.09 ppm for 1H and 13C NMR, respectively, supporting the formation of Schiff bases. The application of Schiff base as spacer in electrochemical DNA (E-DNA) sensor has not been much research done on it so far. The obtained compounds are potentially valuable for electrochemical-DNA sensor study in the future.


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