Syntheses and spectrothermal studies of triethanolamine complexes of Co(II), Ni(II), Cu(II) and Cd(II) squarates

• Published in: Journal of thermal analysis and calorimetry 2007-07, Vol.89 (1), p.261-265
• Main Authors: YESILEL, O. Z, OLMEZ, H
• Format: Article
• Language: English
• Subjects: Cadmium compounds; Chemistry; Coordination compounds; Copper; Decomposition; Dehydration; Differential thermal analysis; Exact sciences and technology; Infrared spectroscopy; Inorganic chemistry and origins of life; Magnetic permeability; Metal oxides; Nickel; Preparations and properties; Spectrum analysis; Thermal decomposition; Thermal stability; Triethanolamine
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-005-7477-y

The triethanolamine complexes, [M(tea)2]sq·nH2O, (n=2 for Co(II), n=0 for Ni(II), Cu(II) and n=1 for Cd(II), tea=triethanolamine, sq2−=squarate), have been synthesized and characterized by elemental analyses, magnetic susceptibility and conductivity measurements, UV-Vis and IR spectra, and thermal analyses techniques (TG, DTG and DTA). The Co(II), Ni(II) and Cu(II) complexes possess octahedral geometry, while the Cd(II) complex is monocapped trigonal prismatic geometry. Dianionic squarate behaves as a counter ion in the complexes. The thermal decomposition of these complexes takes place in three stages: (i) dehydration, (ii) release of the tea ligands and (iii) burning of organic residue. On the basis of the first DTGmax of the decomposition, the thermal stability of the anhydrous complexes follows the order: Ni(II), 289°C>Co(II), 230°C>Cu(II), 226°C>Cu(II), 170°C in static air atmosphere. The final decomposition products — the respective metal oxides — were identified by FTIR spectroscopy.