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Coodination Behaviour of a Pyrazole-Derived Taio-Carboxamide; Cobalt(II), Nickel(II) and Copper(II) Complexes of N, N-Diethyl-5(3)-Methylpyrazole-3(5)-Thiocarboxamide

1988; Taylor & Francis; Volume: 18; Issue: 10 Linguagem: Inglês

10.1080/00945718808060837

1532-2440

Nityananda Saha, Asok Adak, Arunabha Misra,

Organometallic Compounds Synthesis and Characterization

Abstract N, N-Diethyl-5(3)-methylpyrazole-5(5)-thiocarboxamide (DMPTA) forms solid bis-complexes of the type M(DMPTA)2X2.nH20 [M = Co/Ni/Cu; X = a counter ion like Cl/Br/SCN/ 1/2S04/N03/C104/BF/] which have been physico-chemically characterised. Electronic spectral features indicate the chloro- and thiocyanato Co(II) complexes as mixtures of both octahedral and tetrahedral species both in solid and in solution, whereas the rest of the Co(II) complexes are pseudo-octahedral, as is also supported by LF parameters. The geometries of the Ni(II) complexes have been found to be dependent on the counterion (X) present in the species Ni(DMPTA)X2(X2 = (X = N03, 1/2S04, C104) which are diamagnetic with a square planar configuration, while with X = Cl, Br, SCN, the complexes [Ni(DMPTA)X2] are pseudooctahedral. All Cu(II) complexes have distorted octahedral structures. IR data point out the pyra-zolyl ring nitrogen and the sulphur atom of the thioamide residue as the probable coordination sites, showing neutral bidentate (N-S) function of the title ligand.