Synthesis, structural features, antibacterial behaviour and theoretical investigation of two new manganese(III) Schiff base complexes

A review of the tripodal Schiff base (SB) complexes of tris(2-aminoethyl)amine, Nap(CH2CH 2NH2)3 (tren), and a few closely related tripodal amines with Cr(II), Mn(III) (d4), Mn(II), Fe(III) (d5), Fe(II) (d6), and Co(II) (d7) is provided. Attention is focused on examination of key structural features, the M-Nimine, M-Namine, or M-O and M-Nap bond distances and Nimine-M-N(O) bite and C-Nap-C angles and how these values correlate with spin state selection and spin crossover (SCO) behavior. A comparison of these experimental values with density functional theory calculated values is also given. The greatest number, 132, of complexes is observed with cationic mononuclear iron(II) in a N6 donor set, Fe(II)N6. The dominance of two spin states, high spin (HS) and low spin (LS), in these systems is indicated by the bimodal distribution of histogram plots of Fe(II)-Nimine and Fe(II)-Nazole/pyridine bond distances and of Nimine–Fe(II)-Nazole/pyridine and C-Nap-C bond angles. The values of the two maxima, corresponding to LS and HS states, in each of these histograms agree closely with the theoretical values. The iron(II)-Nimine and iron(II)-Nazole/pyridine bond distances correlate well for these complexes. Examples of SCO complexes of this type are tabulated and a few of the 20 examples are discussed that exhibit interesting features. There are only a few mononuclear iron(III) cationic complexes and one is SCO. In addition, a significant number of supramolecular complexes of these ligands that exhibit SCO, intervalence, and chiral recognition are discussed. A summary is made regarding the current state of this area of research and possible new avenues to explore based on analysis of the present data.

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Structural Features of ONS-Donor Salicylidene Schiff Base Complexes

Monatshefte für Chemie - Chemical Monthly ◽

10.1007/s00706-007-0585-6 ◽

2007 ◽

Vol 138 (3) ◽

pp. 175-189 ◽

Cited By ~ 25

Author(s):

Ahmed A. Soliman ◽

Wolfgang Linert

Keyword(s):

Schiff Base ◽

Structural Features ◽

Schiff Base Complexes

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Synthesis and Structural Features of New Schiff Base Complexes of Mononuclear MnIV, Dinuclear CoIICoIII, and Tetranuclear CuII

Zeitschrift für anorganische und allgemeine Chemie ◽

10.1002/zaac.201400554 ◽

2015 ◽

Vol 641 (5) ◽

pp. 941-947 ◽

Cited By ~ 4

Author(s):

Davi F. Back ◽

Gelson Manzoni de Oliveira ◽

Cibele Mensch Canabarro ◽

Bernardo Almeida Iglesias

Keyword(s):

Schiff Base ◽

Structural Features ◽

Schiff Base Complexes

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Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol

Journal of Chemistry ◽

10.1155/2013/724163 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12

Author(s):

C. Anitha ◽

C. D. Sheela ◽

P. Tharmaraj ◽

V. V. Hema

Keyword(s):

Schiff Base ◽

Second Harmonic ◽

Biological Activities ◽

Potassium Dihydrogen Phosphate ◽

Spectroscopic Characterization ◽

Structural Features ◽

Schiff Base Complexes ◽

Spectral Studies ◽

Planar Geometry ◽

Dihydrogen Phosphate

Azo Schiff base complexes of VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from 4-((4-chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol (CDTMP). The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis,1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The EPR spectra of copper(II) complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. The electrochemical behavior of the copper(II) complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate). SEM image of copper(II) complex implies the crystalline state and surface morphology of the complex.

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Synthesis, DNA binding, and antimicrobial studies of novel metal complexes containing a pyrazolone derivative Schiff base

Chemical Papers ◽

10.2478/s11696-010-0003-0 ◽

2010 ◽

Vol 64 (3) ◽

Cited By ~ 19

Author(s):

Natarajan Raman ◽

Ramaraj Jeyamurugan ◽

Mariyyappan Subbulakshmi ◽

Raja Boominathan ◽

Chithu Yuvarajan

Keyword(s):

Schiff Base ◽

Dna Binding ◽

Dna Cleavage ◽

Double Helix ◽

Structural Features ◽

Schiff Base Complexes ◽

Diffusion Method ◽

Spectral Techniques ◽

Antimicrobial Studies

AbstractA novel series of Co(II), Ni(II), Cu(II), Zn(II), and VO(IV) complexes has been synthesized from the Schiff base derived from 4-[(3,4-dimethoxybenzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one and 1,2-diaminobenzene. Structural features were determined by analytical and spectral techniques. Binding of synthesized complexes with calf thymus DNA (CT DNA) was studied by spectroscopic methods and viscosity measurements. Experimental results indicate that the complexes are able to form adducts with DNA and to distort the double helix by changing the base stacking. Lower DNA affinity of the VO(IV) complex is caused by the change of coordination geometry by the vanadyl ion resulting in a somewhat unfavorable configuration for the DNA binding. Oxidative DNA cleavage activities of the complexes were studied with supercoiled (SC) pUC19 DNA using gel electrophoresis; the mechanism studies revealed that the hydroxyl radical is likely to be the reactive species responsible for the cleavage of pUC19 DNA by the synthesized complexes. The in vitro antimicrobial screening effects of the investigated compounds were monitored by the disc diffusion method. The synthesized Schiff base complexes exhibit higher antimicrobial activity than the respective free Schiff base.

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