Syntheses and Study of Some New Coordination Polymers Mn (II) with Semiconductor Properties

Abstract In this paper, the synthesis and the study of some coordination polymers of Mn (II) with ligands derived from acids: dinaphtylphosphinic, dinaphtylthiophosphinic and dinaphtyldithiophosphinic are presented. The synthesis was accomplished by refluxing in organic solvents the reactants: acetylacetonate of Mn (II) and one of the respective phosphinic acids. Studies were performed applying the following methods: chemical analysis, gel chromatography: IR-spectroscopy; ESR, X-ray diffraction, thermogravimetric analysis and electrical resistance measurements in the field of temperature 20–200°C. All the studied compounds present semiconductor properties, having the resistivity of 10−8 ohm·cm−1. The activation energy is approximately 0.9 eV; they also present a good thermal stability resisting to the heat effect till at least 300°C. The semiconductor properties are depending on the nature of the ligands. These results are comparable to the semiconductor properties of other coordination polymers of transitional metals. Based on experimental data and literature indications, the structural formulae of these compounds are assigned. Keywords: Mn (II) polyphosphinate phosphinate semiconductor properties coordination polymers