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 (HL.2HCl) and its coordination compounds with Mn(II) - [Mn(HL)·Cl2], Co(III) - [CoL2]·ClO4, Ni(II) - [Ni(HL)2]·2ClO4, Cu(II) - [Cu(HL)Cl2]·(H2O), Zn(II) - [Zn(HL)2]·2(ClO4)·(H2O) and Pd(II) - [Pd(HL)·Cl]·Cl 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. [Display omitted] •Synthesis of 2-formylpyridine S-methyl-isothiosemicarbazide as proligand.•Three different types of coordination with transitional metals for the new proligand.•Crystal structures of the new proligand complexes with Mn, Co, Cu, Zn and Pd.•An interesting structure adaptability of the new ligand in coordination complexes.