Preparation, Spectroscopic, Magnetic, Conductometric and Polarographic Characterization of Cobalt(II)-1-phenyl-4,6-dimethylpyrimidine-2-thione Complexes

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Title:Preparation, Spectroscopic, Magnetic, Conductometric and Polarographic Characterization of Cobalt(II)-1-phenyl-4,6-dimethylpyrimidine-2-thione Complexes
Creators:
Borsari, Marco
Battistuzzi, Gianantonio
Battistuzzi, Raffaele
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 58, 7, pp. 1569-1590

Abstract

The following coordination compounds of cobalt(II) with 1-phenyl-4,6-dimethylpyrimidine-2-thione: CoLX<sub>2</sub> . <i>n</i> H<sub>2</sub>O ( X = Cl<sup>-</sup>, <i>n</i> = 1; X = Br<sup>-</sup>, <i>n</i> = 2; X =SCN<sup>-</sup>, <i>n</i> = 0; X = NO<sub>3</sub><sup>-</sup>, <i>n</i> = 4), Co<sub>2</sub>L<sub>3</sub>Cl<sub>4</sub> . H<sub>2</sub>O, CoL<sub>2</sub>X<sub>2</sub> (X = Br<sup>-</sup>, I<sup>-</sup>, SCN<sup>-</sup>, NO<sub>3</sub><sup>-</sup>), CoL<sub>2</sub>X<sub>2</sub> . <i>n</i> H<sub>2</sub>O . <i>p</i> Me<sub>2</sub>CO (X = I<sup>-</sup>, ClO<sub>4</sub><sup>-</sup>, <i>n</i> = <i>p</i> = 2; X = NO<sub>3</sub><sup>-</sup>, <i>n</i> = 1, <i>p</i> = 0), CoL<sub>3</sub>(ClO<sub>4</sub>)<sub>2</sub> . 0.5 Me<sub>2</sub>CO, Co<sub>2</sub>L<sub>5</sub>(NO<sub>3</sub>)<sub>4</sub> and Co<sub>2</sub>L<sub>7</sub>X<sub>4</sub> (X = Cl<sup>-</sup>, Br<sup>-</sup>, I<sup>-</sup>) have been isolated and characterized by chemical analyses, visible and IR spectra, paramagnetic susceptibility, conductivity and polarographic measurements. Solid phase IR spectra suggest that the heterocyclic ligand is almost always bonded through non-substituted ring nitrogen and exocyclic sulfur atoms. The solid compounds with the exception of the [CoL(SCN)<sub>2</sub>]<sub>2</sub>, [CoL<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>][CoCl<sub>4</sub>] and [CoL<sub>3</sub>][CoCl<sub>4</sub>] . H<sub>2</sub>O have originally a distorted octahedral geometry. By grinding the solid [CoL<sub>2</sub>(SCN)<sub>2</sub>], Co<sub>2</sub>L<sub>7</sub>Cl<sub>4</sub> and all the bromide complexes the cobalt(II) coordination undergo octahedral (T> tetrahedral geometry change. Spectral evidences and polarographic results in DMF solution have shown that for these and [CoL(SCN)<sub>2</sub>]<sub>2</sub>, [CoL<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>][CoCl<sub>4</sub>] and [CoL<sub>3</sub>][CoCl<sub>4</sub>] . H<sub>2</sub>O complexes, the solvolysis gives rise to equilibria between tetrahedral anionic [CoX<sub>4</sub>]<sup>2-</sup> (X = SCN<sup>-</sup>, Cl<sup>-</sup>), [CoX<sub>3</sub>(DMF)]<sup>-</sup> (X = SCN<sup>-</sup>, Cl<sup>-</sup>, Br<sup>-</sup>) and some possible [Co(DMF)<sub>6</sub>]<sup>2+</sup>, [CoX(DMF)<sub>5</sub>]<sup>+</sup>, [CoXL(DMF)<sub>4</sub>]<sup>+</sup>, [CoL(DMF)<sub>5</sub>]<sup>2+</sup> (L = N-monodentate ligand) cationic octahedral species. Polarographic data for perchlorate complexes and for [Co(DMF)<sub>6</sub>](ClO<sub>4</sub>)<sub>2</sub>-L system at increasing ligand concentration have shown that in DMF solution the solved ions [Co(DMF)<sub>6</sub>]<sup>2+</sup> are the prevailing species and that the thiopyrimidine-containing species [CoL(DMF)<sub>5</sub>]<sup>2+</sup> (β = 3.78 . 10<sup>5</sup>) and [CoL<sub>2</sub>(DMF)<sub>4</sub>]<sup>2+</sup> (β =9.59 . 10<sup>7</sup>) can be formed only in presence of large excess of the free ligand.

Title:Preparation, Spectroscopic, Magnetic, Conductometric and Polarographic Characterization of Cobalt(II)-1-phenyl-4,6-dimethylpyrimidine-2-thione Complexes
Creators:
Borsari, Marco
Battistuzzi, Gianantonio
Battistuzzi, Raffaele
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:58
Number:7
Page Range:pp. 1569-1590
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19931569UNSPECIFIED
ID Code:276
Item Type:Article
Deposited On:06 Feb 2009 16:59
Last Modified:06 Feb 2009 15:59

Citation

Borsari, Marco; Battistuzzi, Gianantonio; Battistuzzi, Raffaele (1993) Preparation, Spectroscopic, Magnetic, Conductometric and Polarographic Characterization of Cobalt(II)-1-phenyl-4,6-dimethylpyrimidine-2-thione Complexes. Collection of Czechoslovak Chemical Communications, 58 (7). pp. 1569-1590. ISSN 0010-0765

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