Nucleophilic additions in Cu(II), Ni(II), Co(II) pseudohalide-4-halogenopyrazole systems

From M(II)-Y--4-X-pz systems, where M = Cu, Ni, Co; Y = NCO, C(CN)(3), N(CN )(2); X = Cl, Br, I (pz = pyrazole), new compounds of the type [MY2(4 -X-pz )(2)] and [M(4-X-pz.Y)(2)] have been prepared. Compounds [M(4-X-pz.Y)(2)] a rise by nucleophilic addition of imine nitrogen from 4-X-pz to cyano carbon of the pseudohalide under formation of five-membered metallocycle. The inf luence of X substituent on the course of this reaction with various M(II) a nd Y was investigated. An uncomplete course of nucleophilic addition is rev ealed by formation of mixed products, consisting of [MY2(4-X-pz)(2)] and [M (4-X-pz.Y)(2)]. All compounds were studied by infrared and electronic spect roscopy and probable structures were assigned to the relevant species.