New Complexes of Polyurea with Copper (II), Manganese (II) and Chromium (III) (Synthesis and Characterization)

Abstract

New coordination polymers of the transition metal ions Cu(II), Mn(II)m
Cr(III) with six polyurea ligands were prepared. The polyurea ligands were
synthesized by the condensation of urea with the corresponding diamine. These
ligands were:
- Poly (N,N`-1,4-phenylene diamine) urea (PPU)
- Poly (N,N`-1,3-phenylene diamine) urea (PMU)
- Poly (N,N`-1,2-phenylene diamine) urea (POU)
- Poly (N,N`-2,4-Toluidene diamine) urea (PTU)
- Poly (N.N`-Benzidene) urea (PBU)
- Poly (N,N`-ethylene diamine) urea (PEU)

The prepared compounds were characterized by elemental analysis, UV, IR
and H1NMR spectroscopy and magnetic susceptibility measurements. Moreover,
thermal stability were investigated by thermogravimetric analysis (TGA). For
polyureas it was found that increasing aromaticity inhances thermal stability as
follows:
PBU > PPU > PMU ≈ PTU > POU > PEU
On the other hand, the higher thermal stability was observed for Mn(II)
followed by Cr(III) then Cu(II) complexes. The structure of the complexes was
suggested on the basis of the physicochemical measurements obtained. The ligand acts as mono or bidentate with copper and manganese complexes with tetracoordination while the chromium complexes are hexadentate