Mononuclear and polynuclear chelates of picolinoyldithiocarbazate

Mononuclear and polynuclear chelates of potassium picolinoyldithiocarbazate (KHPcDC) with Mn(II), Fe(III), Fe(II), Co(II), Ni(ll), Cu(II), Zn(II), Cd( II), Hg(II), Pd(II) and U(VI)O-2 have been prepared and characterized by ch emical and thermal (TG, DTG, DTA) analyses, molar conductivities, spectral (UV-Visible, IR, NMR ESR) and magnetic moment measurements. The molar condu ctivities of the completes lie in the non-electrolyte range whilst KHPcDC i s a 1 :1 electrolyte. Changes in selected vibrational absorption of the lig and upon coordination Indicate that KHPcDC behaves as monoanionic and coord inates in a bidentate, tridentate and/or bridging tetradentate manner. Tran s-form structure is proposed far [Pd(HPcDC)(2)] . 2H(2)O and [Cd(HPcDC)(2)] complexes on the basis of NMR data. An octahedral structure is proposed fo r Fe(III), Fc(II) and Ni(II) complexes, a square-planar structure for Co(II ) and Pd(II) complexes and a tetragonally distorted octahedral structure fo r the Cu(II) chelate on the basis of spectroscopic and magnetic data. The l igand field parameters (B, Dq, beta) for the Fe(III) and Ni(II) chelates we re calculated. TG, DTG and DTA. studies support the different modes of chel ation of I KHPcDC. The solid metal acetate chelates have a unique decomposi tion exotherm profile which can be used as a rapid and sensitive tool for t he detection of acetate-containing complexes.