New M(II) (M=Mn, Co, Ni, Cu, Zn, Pd) coordinative compounds with 2-formylpyridine S-methyl-isothiosemicarbazide

The synthesis and structure of the new organic proligand 2-formylpyridine S-methyl-isothiosemicarbazone in a bi-protonated form (HL2HCI) and its coordination compounds with Mn(II) - [Mn(HL)center dot CI2],Co(III) - [CoL2]center dot CIO4, Ni(II) - Ni(HL)(2)]center dot 2CIO(4), Cu(II) - [Cu(HL)CI2]center dot(H2O), Zn(II) - [Zn(HL)(2)]center dot 2(CIO4)center dot(H2O) and Pd(II) - [Pd(HL)center dot CI]center dot CI are reported. According to the X-ray investigation, the ligand has the molecular form of HL in the case of Mn(II), Cu(II), Zn(II) and Pd(II) compounds, and the deprotonated form L- in case of the Co(III) complex. The ligand coordinates to the metal ions via a N,N,N set of donors atoms in case of Zn(II), Cu(II) and Co(III). For Mn(II), the ligand coordinates via N,N donor atoms, whereas in the case of Pd(II) metal ions, the coordination sphere is N,N,S. This latter coordination mode (via S(CH3)) has been previously reported in case of salicylaldehyde S-alkyl-isothiosemicarbazones. (C) 2020 Elsevier B.V. All rights reserved.