Physical characteristics, vibrational spectroscopy and normal-coordinate analysis of 2-aminophenol and 2-phenylenediamine complexes

• Published in: Polyhedron Vol. 21; no. 9; pp. 987 - 996
• Main Authors: Bahgat, Khaled, Orabi, Adel S
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2002
• Subjects: 2-Aminophenol; 2-Phenylenediamine; Cd(II) and Hg(II) complexes; Force constant; Normal coordinate; Spectroscopic properties; Spectroscopic properties; Force constant; 2-Phenylenediamine; Cd(II) and Hg(II) complexes; 2-Aminophenol; Normal coordinate
• ISSN: 0277-5387
• DOI: 10.1016/S0277-5387(02)00910-5

Hg(II) and Cd(II) complexes with 2-aminophenol ( Amph) and 2-phenylenediamine ( Phda) as ligands were prepared and characterized by elemental analysis, electrical conductivity, thermogravimetric analysis (DTA/TG), X-rays, FT-IR and FT-Raman spectra. The complexes formed can be formulated as [M(L) 2· nH 2O]· mH 2O. The electrical conductivity of 0.001 M DMSO solutions revealed the non-electrolytic behavior of the Amph complexes while Phda complexes behave as a 1:2 electrolyte. DTA analysis reveals the presence of two types of water coordinating as aligned and as water of crystallization. Δ E a of the stepwise decomposition was evaluated. X-ray powder diffraction studies on the ligands and their complexes are described. The fundamental frequencies of these complexes have been assigned on the basis of normal coordinate calculations, carried out using a generalized valence force field (GVFF). The proposed assignments are discussed in relation to the group frequencies in structurally related molecules and in terms of the computed potential-energy distributions among the symmetry coordinates. The vibrational spectra of the metal chelates of 2-aminophenol ( Amph) and 2-phenylenediamine ( Phda) are interesting from the viewpoint of molecular spectroscopy. The nature of the MN and MO bonds has been a subject of interest. The bands at 447 and 411 cm −1 are assigned to ν(MN) in the i.r. spectra of Phda complexes. ν(MO) bands are observed at 458 and 448 cm −1 in i.r. spectra of Amph complexes.