Sensors 2006, 6(11), 1708-1720; doi:10.3390/s6111708
Article

Spectroscopic Characteristics of Highly Selective Manganese Catalysis in Acqueous Polyurethane Systems

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Received: 25 September 2006; Accepted: 12 November 2006 / Published: 20 November 2006
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The latest investigations on producing more efficient catalytic aqueouspolyurethane systems are in the domain of metal complexes with mixed ligands. In ourprevious research works, the high selectivity for the isocyanate-hydroxyl reaction inaqueous polyurethane systems has been shown by the manganese(III) mixed-ligandcomplexes. The two new complexes have been prepared with two acetylacetonate (acac)ligands and one maleate ligand and its hydroxylamine derivative of the general formula[Mn(C5H7O2)2L]. Their structures have been established by using the fundamental analyses,the FTIR and UV/VIS spectroscopic methods, as well as the magnetic measurements. Inorder to explain the different selectivity of the manganese(III) mixed-ligand complexes, theUV and ESR spectroscopy have been employed to determine the kinetics of the complexes’decomposition. The thermal stability of the complexes has been determined by way of thedynamic TG method at the heating rate of 5°C⋅min-1 and at the temperature ranged 20-550°C. It suggests the decomposition of the complexes by loss of acid ligand. The main factor in the selective catalysis control in theaqueous polyurethane systems is the nature of the acid ligands and their impact on themanganese(II)/manganese(III) equilibrium.
Keywords: catalyst’s selectivity; manganese(III) complexes; fourier transform infrared spectra (FTIR); electronic spectra (UV); electron spin resonance (ESR).
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MDPI and ACS Style

Cakic, S.; Lacnjevac, C.; Nikolic, G.; Stamenkovic, J.; Rajkovic, M.B.; Gligoric, M.; Barac, M. Spectroscopic Characteristics of Highly Selective Manganese Catalysis in Acqueous Polyurethane Systems. Sensors 2006, 6, 1708-1720.

AMA Style

Cakic S, Lacnjevac C, Nikolic G, Stamenkovic J, Rajkovic MB, Gligoric M, Barac M. Spectroscopic Characteristics of Highly Selective Manganese Catalysis in Acqueous Polyurethane Systems. Sensors. 2006; 6(11):1708-1720.

Chicago/Turabian Style

Cakic, Suzana; Lacnjevac, Caslav; Nikolic, Goran; Stamenkovic, Jakov; Rajkovic, Milos B.; Gligoric, Miladin; Barac, Miroljub. 2006. "Spectroscopic Characteristics of Highly Selective Manganese Catalysis in Acqueous Polyurethane Systems." Sensors 6, no. 11: 1708-1720.

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