The synthesis, spectroscopic and thermal study of oxamic acid compounds of some metal(II) ions

✍ Scribed by Christoffel Vansant; Herman O. Desseyn; Spyros P. Perlepes

• Book ID: 104639144
• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 454 KB
• Volume: 20
• Category: Article
• ISSN: 0340-4285
• DOI: 10.1007/bf00141516

✦ Synopsis

The preparation of oxamic acid complexes of general formula M(H2NCOCOO)2.xH20 (M = Mn II, Co II, Ni", Cu n or znn; x = 1 for Cu n, x = 2 for the other metals) is H C N M reported. The i.r. and Raman spectra are discussed considering a trans-octahedral structure, formed by five-Mn(H2NCOCOO)2'2H20 2.2 19.0 7.2 21.3 membered chelate rings with the amide oxygen and one (3.0) (18.0) (10.5) (20.6) carboxylic oxygen as donor atoms. The apical positions C~ 2.2 18.0 10.0 19.8 (3.0) (17.7) (10.3) (21.7) are occupied by water molecules. The thermal degrada-Ni(H2NCOCOO)2.2H20 3.1 17.4 9.1 21.2 tion process is very similar for the different complexes, (3.0) (17.7) (10.3) (21.7) first losing H20 in one or different steps, then the frag-Cu(H2NCOCOO)2.H20 2.7 17.9 10.4 23.8 ments of the organic ligand to give the metal oxide as (2.4) (18.7) (10.9) (24.7) residue. The thermal degradation of the Cu n and Zn n Zn(HzNCOCOO)2.2H20 2.2 18.2 10.0 18.5 compounds results in the formation of a new polymeric

(2.9) (17.3) (10.1) (23.6) compound by deprotonation of the primary amide function in an endothermic process, the polymer further decomposes to form the metal oxide.