Electrochemical and Spectroscopic Studies of Pyridazine Derivatives

 

L.M.C. Vieira,^a A.M. Fonseca, ^a,*M.M.M. Raposo,^a G. Kirsch^b

 

^aDepartamento de Química, Universidade do Minho, Campus de Gualtar,

4710-057, Braga, Portugal.

^bLaboratoire d´Ingénierie Moléculaire et Biochimie Pharmacologique, Faculté de Sciences, Université de Metz, 57012 Metz, France.

 

Received 15 September 2003; Accepted in revised form 6 November 2003

 

Abstract

This work reports on cyclic voltammetry and spectroscopic UV-Vis investigations of some pyridazine derivatives 1-8 in dimethylformamide. In the electrochemical study, monochlorinated pyridazines 2-8 exhibit two reductions but in the case of dichlorinated derivative 1 an additional wave is seen for the reduction of the second carbon-chloride bond. The electronic absorption spectra display an intramolecular charge transfer band π-π* in the UV region of which depend substantially on the nature of both donor and acceptor moieties. These results indicate the π-electron delocalization in the conjugated system.

 

Keywords: pyridazines; electrochemistry; electronic spectra; donor-π -bridge-acceptor systems.

 

Texto completo disponível apenas em PDF.

Full text only in PDF format.

 

 

References

1. W.J. Coates, in Pyridazines and Their Benzo Derivatives, Comprehensive Heterocyclic Chemistry II, A.R. Katritzky, C.W. Rees, E.F.V. Scriven, Eds., Vol. 6, Pergamon Press, Oxford, 1996. p. 1.        [ Links ]

2. N.-D. Sung, K-S. Yung, T-Y. Kim, K-Y. Choi, M. Such, J-G. Kim, I-H Suh, J. Chin, Inorg. Chem. Comunn. 4(2001) 377.        [ Links ]

3. S. Brooker, T.C. Davidson, S.J. Hay, R.J. Kelly, D.K. Kennepohl, P.G. Plieger, B. Moubaraki, K.S. Murray, E. Bill, E. Bothe, Coord. Chem. Rev. 216-217 (2001) 3.        [ Links ]

4. Y. Cheng, B. Ma, F. Wudl, J. Mat. Chem . 9 (1999) 2183.         [ Links ]

5. J.J. Wolf, R. Wortmann, Adv. Phys. Org. Chem. 32 (1999) 121.        [ Links ]

6. A.K.-Y. Jen, Y.M. Cai, P.V. Bedworth, S.R. Marder, Adv. Mater. 9 (1997) 12.        [ Links ]

7. S.R. Marder, C.B. Gorman, B.G. Tiemann, K. Clays, A. Persoons, J. Mater. Chem.7 (1997) 2175.        [ Links ]

8. A.M.B.A. Sampaio, in Síntese de heterociclos derivados de tiofeno com potencialactividade biológica ou aplicação em óptica não-linear, M.Sc. thesis, Department of Chemistry, University of Minho, 2002.        [ Links ]

9. M.S. Mubarak, D.G. Peters, J. Electroanal. Chem. 507 (2001) 110.        [ Links ]

10. C. Ji, D.G. Peters, J. Electroanal. Chem. 455 (1998) 147.        [ Links ]

11. C. Ji, D.G. Peters, E. R. Davidson, J. Electroanal. Chem. 500 (2001) 3.        [ Links ]

 

 

^*Corresponding author. E-mail address: amcf@quimica.uminho.pt (A.M. Fonseca).