Coordination behaviours of new (bidentate N,O-chelating) Schiff bases towards copper(II) and nickel(II) metal ions: synthesis, characterization, antimicrobial, antioxidant, and DFT studies

Coordination behaviours of new (bidentate N,O-chelating) Schiff bases towards copper(II) and... Two Schiff bases, HL1 and HL2, were synthesized in two different reactions involving 2-hydroxynaphthaldehyde with 2-amino-6-methylbenzothiazole and 2-amino-6-florobenzothiazole respectively. Copper(II) and nickel(II) complexes of the Schiff bases were subsequently prepared in 1:1 metal-to-ligand stoichiometric reactions. The compounds were characterized extensively by 1H NMR, 13C NMR, Dept-90, UV–Vis, and IR spectroscopic techniques, magnetic susceptibility, TGA, DTG, and molar conductivity analysis. The spectroscopic results confirm bidentate nature of the Schiff bases and a four coordinate geometry for all the complexes: [CuL1ClH2O], [NiL1ClH2O], [Cu(L2)2], and [NiL2ClH2O]. Quantum chemical studies gave fully optimized geometries of the Schiff bases and metal complexes using the 6-31+g(d,p) basis set. The compounds were studied for their in vitro antibacterial activities against some selected Gram-positive and Gram-negative bacteria, using agar well diffusion. The metal complexes exhibited better antibacterial activities compared to the free ligand due to the effects of chelation, which improved the lipophilicity. Furthermore, the antioxidant potentials of the compounds were ascertained using DPPH radical scavenging and ferrous chelating assay. The copper complexes had the best antioxidant properties of all the tested compounds. The results of the biological analysis were in agreement with the theoretical data from quantum chemical calculations. The study presented biologically active coordination compounds with benzothiazole moiety that could be used as compounds of interest in the drug discovery processes. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Research on Chemical Intermediates Springer Journals

Coordination behaviours of new (bidentate N,O-chelating) Schiff bases towards copper(II) and nickel(II) metal ions: synthesis, characterization, antimicrobial, antioxidant, and DFT studies

Loading next page...
 
/lp/springer_journal/coordination-behaviours-of-new-bidentate-n-o-chelating-schiff-bases-0sz0TEh8lS
Publisher
Springer Netherlands
Copyright
Copyright © 2017 by Springer Science+Business Media Dordrecht
Subject
Chemistry; Catalysis; Physical Chemistry; Inorganic Chemistry
ISSN
0922-6168
eISSN
1568-5675
D.O.I.
10.1007/s11164-016-2841-z
Publisher site
See Article on Publisher Site

Abstract

Two Schiff bases, HL1 and HL2, were synthesized in two different reactions involving 2-hydroxynaphthaldehyde with 2-amino-6-methylbenzothiazole and 2-amino-6-florobenzothiazole respectively. Copper(II) and nickel(II) complexes of the Schiff bases were subsequently prepared in 1:1 metal-to-ligand stoichiometric reactions. The compounds were characterized extensively by 1H NMR, 13C NMR, Dept-90, UV–Vis, and IR spectroscopic techniques, magnetic susceptibility, TGA, DTG, and molar conductivity analysis. The spectroscopic results confirm bidentate nature of the Schiff bases and a four coordinate geometry for all the complexes: [CuL1ClH2O], [NiL1ClH2O], [Cu(L2)2], and [NiL2ClH2O]. Quantum chemical studies gave fully optimized geometries of the Schiff bases and metal complexes using the 6-31+g(d,p) basis set. The compounds were studied for their in vitro antibacterial activities against some selected Gram-positive and Gram-negative bacteria, using agar well diffusion. The metal complexes exhibited better antibacterial activities compared to the free ligand due to the effects of chelation, which improved the lipophilicity. Furthermore, the antioxidant potentials of the compounds were ascertained using DPPH radical scavenging and ferrous chelating assay. The copper complexes had the best antioxidant properties of all the tested compounds. The results of the biological analysis were in agreement with the theoretical data from quantum chemical calculations. The study presented biologically active coordination compounds with benzothiazole moiety that could be used as compounds of interest in the drug discovery processes.

Journal

Research on Chemical IntermediatesSpringer Journals

Published: Jan 3, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off