Synthesis and spectral studies of new N2S2 and N2O2 Mannich base ligands and their metal complexes

• Published in: Journal of coordination chemistry 2009-08, Vol.62 (16), p.2736-2744
• Main Authors: Abdul-Ghani, Ahlam Jamil, Al-Jeboori, Mohamad Jaber, Al-Karawi, Ahmed Jasim M.
• Format: Article
• Language: English
• Subjects: Bis(1-phenylsemicarbazide methyl) phosphinic acid; Bis(thiosemicarbazide methyl) phosphinic acid; Mannich bases; Structural study; Transition metal complexes
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958970902878327

New Mannich bases bis(thiosemicarbazide methyl) phosphinic acid H 3 L 1 and bis(1-phenylsemicarbazide methyl) phosphinic acid H 3 L 2 were synthesized from condensation of phosphinic acid and formaldehyde with thiosemicarbazide and 1-phenylsemicarbazide, respectively. Monomeric complexes of these ligands, of general formula K 2 [Cr III (L n )Cl 2 ], K 3 [Fe II (L 1 )Cl 2 ], K 3 [Mn II (L 2 )Cl 2 ], and K[M(L n )] (M = Co(II), Ni(II), Cu(II), Zn(II) or Cd(II); n = 1, 2) are reported. The mode of bonding and overall geometry of the complexes were determined through IR, UV-Vis, NMR, and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, and conductance. These studies revealed octahedral geometries for the Cr(III), Mn(II), and Fe(II) complexes, square planar for Co(II), Ni(II), and Cu(II) complexes and tetrahedral for the Zn(II) and Cd(II) complexes. Complex formation via molar ratio in DMF solution has been investigated and results were consistent to those found in the solid complexes with a ratio of (M : L) as (1 : 1).