Self-assembling dicopper(II) complexes of di-2-pyridyl ketone Schiff base ligands derived from S-alkyldithiocarbazates

• Published in: Polyhedron Vol. 30; no. 9; pp. 1478 - 1486
• Main Authors: Akbar Ali, Mohammad, Mirza, Aminul H., Butcher, Ray J., Bernhardt, Paul V., Karim, Mohammad Rezaul
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 26-05-2011
• Subjects: Copper(II) complexes; Di-2-pyridyl ketone Schiff base of S-benzyldithiocarbazate; Dithiocarbazates; Dithiocarbazates; Copper(II) complexes; Di-2-pyridyl ketone Schiff base of S-benzyldithiocarbazate
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2011.02.048

Complexation of di-2-pyridyl ketone Schiff bases of S-methyl- and S-benzyldithiocarbazates with Cu(II) in a 1:1
M ratio leads to the formation of dinuclear complexes of the general formula [Cu(NNNS)X]
2 (X
=
Cl
−, NO
3
−, H
2O) in which each ligand provides three donor atoms (NNS) in a meridional configuration to one metal,
viz. one of the pyridine nitrogen atoms, the azomethine nitrogen atom and the thiolate sulfur, while the nitrogen atom of the second pyridyl group forms a bridge to another copper(II) ion within the dimer.
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► Reaction of copper(II) with the potentially bridging ligands, Py
2C
=
NNHC(S)SR (R
=
Me, Bz) in a 1:1 molar ratio yields dinuclear complexes of general formula, [Cu(NNNS)X]
2 (X
=
Cl
−, NO
3
−, H
2O). ► X-ray crystallographic structure determinations show that each ligand provides three donor atoms (NNS) in a meridional configuration to one metal while the nitrogen atom of the second pyridyl group forms a bridge to another copper(II) ion within the dimer. ► The coordination geometry around each copper(II) ion is approximately square-pyramidal.
Condensation of di-2-pyridyl ketone with S-methyldithiocarbazate or S-benzyldithiocarbazate yields potentially bridging ligands of the form Py
2C
NNHC(S)SR; Hdpksme (R
=
Me; the di-2-pyridyl ketone Schiff base of S-methyldithiocarbazate) and Hdpksbz (R
=
Bz; the di-2-pyridyl ketone Schiff base of S-benzyldithiocarbazate). Complexation of these ligands with Cu(II) in a 1:1
M ratio leads to the formation of dinuclear complexes of the general formula [Cu(NNNS)X]
2 (X
=
Cl
−, NO
3
−, H
2O). X-ray crystallographic structure determinations show that each ligand provides three donor atoms (NNS) in a meridional configuration to one metal,
viz. one of the pyridine nitrogen atoms, the azomethine nitrogen atom and the thiolate sulfur, while the nitrogen atom of the second pyridyl group forms a bridge to another copper(II) ion within the dimer. The coordination geometry around each copper(II) ion is approximately square pyramidal, the basal plane of which is composed of one of the pyridine nitrogen atoms, the azomethine nitrogen atom and a chlorido, nitrato or aqua ligand. The apical position of the square pyramid is always occupied by the pyridine nitrogen atom of the second ligand.