Structural single crystal, thermal analysis and vibrational studies of the new rubidium phosphate tellurate Rb2HPO4RbH2PO4·Te(OH)6

AbstractThe determination of the crystalline structure of rubidium phosphate tellurate Rb2HPO4RbH2PO4·Te(OH)6 [RbPTe] is performed from single crystal X-ray diffraction data. The title compound crystallizes in the monoclinic system P2. The unit cell parameters are as follows: a=7.9500(7)Å, b=6.3085(6)Å, c=9.5008(9)Å, β=109.783(4)°, Z=2 and V=448.37(7)Å3.The crystal structure is constituted from isolated (PO43-) tetrahedra and (TeO66-) octahedra and two nonequivalent Rb+ cations. Material cohesion is built of O–H⋯O bondings and ionic interactions.The new synthesized material has been characterized using the differential scanning calorimetry (DSC), thermal analysis [differential thermogravimetric analysis (TG), thermodifference analysis (DTA) and the mass spectrometric analysis], FT-IR and Raman techniques.Thermal analysis, in the temperature range of 300–900K, confirms that the decomposition of this material took place in two steps. The differential scanning calorimetry analysis shows three endothermic peaks at 451, 463 and 481K.The existence of anionic groups in the structure has been confirmed by IR and Raman spectroscopy in the frequency ranges 3000–600cm−1 and 1300–50cm−1, respectively

Structural single crystal, thermal analysis and vibrational studies of the new rubidium phosphate tellurate Rb2HPO4RbH2PO4·Te(OH)6

The determination of the crystalline structure of rubidium phosphate tellurate Rb2HPO4RbH2PO4·Te(OH)6 [RbPTe] is performed from single crystal X-ray diffraction data. The title compound crystallizes in the monoclinic system P2. The unit cell parameters are as follows: a = 7.9500(7) Å, b = 6.3085(6) Å, c = 9.5008(9) Å, β = 109.783(4)°, Z = 2 and V = 448.37(7) Å3. The crystal structure is constituted from isolated () tetrahedra and () octahedra and two nonequivalent Rb+ cations. Material cohesion is built of O–H⋯O bondings and ionic interactions. The new synthesized material has been characterized using the differential scanning calorimetry (DSC), thermal analysis [differential thermogravimetric analysis (TG), thermodifference analysis (DTA) and the mass spectrometric analysis], FT-IR and Raman techniques. Thermal analysis, in the temperature range of 300–900 K, confirms that the decomposition of this material took place in two steps. The differential scanning calorimetry analysis shows three endothermic peaks at 451, 463 and 481 K. The existence of anionic groups in the structure has been confirmed by IR and Raman spectroscopy in the frequency ranges 3000–600 cm−1 and 1300–50 cm−1, respectively.This work is supported by the Ministry of Superior Education and Research of Tunisia.Peer Reviewe

Decolorization of the azo dye Acid Orange 51 by laccase produced in solid culture of a newly isolated Trametes trogii strain

11 p.-5 fig.-6 tab.This study concerns the decolorization and detoxification of the azo dye Acid Orange 51 (AO51) by crude laccase from Trametes trogii produced in solid culture using sawdust as support media. A three-level Box–Behnken factorial design with four factors (enzyme concentration, 1-hydroxybenzotriazole (HBT) concentration, dye concentration and reaction time) combined with response surface methodology was applied to optimize AO51 decolorization. A mathematical model was developed showing the effect of each factor and their interactions on color removal. The model predicted that Acid Orange 51 decolorization above 87.87 ± 1.27 % could be obtained when enzyme concentration, HBT concentration, dye concentration and reaction time were set at 1 U/mL, 0.75 mM, 60 mg/L and 2 days, respectively. The experimental values were in good agreement with the predicted ones and the models were highly significant, the correlation coefficient (R 2) being 0.9. Then the desirability function was employed to determine the optimal decolorization condition for each dye and minimize the process cost simultaneously. In addition, germination index assay showed that laccase-treated dye was detoxified; however in the presence of HBT, the phytotoxicity of the treated dye was increased. By using cheap agro-industrial wastes, such as sawdust, a potential laccase was obtained. The low cost of laccase production may further broaden its application in textile wastewater treatment.Peer reviewe