THE COMPLEX OF Ni(II) WITH 3,5-DIMETHYL-1H-PYRAZOLE-1-CARBOXAMIDINIUM NITRATE

Abstract

Pyrazole derivatives, beside of their various practical applicability are known of their rich coordination modes [1, 2]. Lots of them and their complexes with transition metals are used as active components of pharmaceutics (analgetics, antireumatics, antipiretics) [3]. Other pyrazole based compounds are used in industry as materials for thin film production [4], as catalysts [5] or ionophores [6]. Some of pyrazole based complexes are suitable for modeling metabolic processes [7]. In this paper a new complex of nickel(II) with 3,5-dimethyl-1H-pyrazole-1-carboxamidinium nitrate (dpca∙HNO3) of formula [Ni(dpca)2(H2O)2](NO3)2∙H2O is described. The octahedral geometry in this complex around Ni(II) is established by bidentate coordination of two dpca ligands and two molecules of water in cis-position while the corresponding trans-dpca complex is already described [8]. The complex cation is formed by coordination of the ligand by N2 atom of the pyrazole ring and N1 atom of the substituent and two water molecules being in cis positions (see figure). The electroneutrality of the complex is accomplished by two nitrate contraions. The compound crystallizes with one water molecule. Trans-angles of 177.2° (N1–Ni–N1’), 168.3° (N2–Ni–O1’) and 168.3° (N2’–Ni–O1) refer to a slightly deformed structure. [1] Rabindranath Mukherjee, Coordination Chemistry Reviews, 203 (2000) 151–218 [2] Ahmed A. Mohamed, Coordination Chemistry Reviews, 254 (2010) 1918–1947 [3] S. A. M. El-Hawash, E. S. A. M. Badawey, I. M. El-Ashmawey, European Journal of Medicinal Chemistry, 41 (2006) 155–165 [4] C. Yélamos, K. R. Gust, A. G. Baboul, M. J. Heeg, H. B. Schlegel, C. H. Winter, Inorganic Chemistry, 40 (2001) 6451-6462 [5] A. Dehestani, A. Wu, R. Hayoun, W. Kaminsky, J. M. Mayer, Inorganica Chimica Acta, 362 (2009) 4534–4538 [6] A. K. Singh, V. Aggarwal, U. P. Singh, S. Mehtab, Talanta, 77 (2008) 718–726 [7] R. Hille, Chemical Reviews, 96 (1996) 2757-2816 [8] Ž. K. Jaćimović, V. M. Leovac, K. Mészáros Szécsényi, I. Radosavljević Evans, J. A. K. Howard, Acta Crystallographica Section C, 3C60 (2004) m467-m470