Study On The Synthesis, Characterization And Thermodynamic Properties Of Rubidium Compound

Studies on rare alkali metal rubidium are very few, because of its dispersion and rare. In recent years, with the development of studies on the application, biological essentiality and health effect on humans, it is of importance to study the crystal structure, physicochemical and thermodynamic property of rubidium compounds.In this paper, the second part of is the experiments part, eleven compounds of rubidium were obtained by reacting Rb₂CO₃ and 3-carboxy-4-hydrobenzensulfonic acid, sulfosalicylic acid, aspartic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, terephthalic acid, p-hydroxy benzoic acid, p-toluene sulfonic acid, tartrate, 5-aminotetrazole. Also seven rubidium compounds of Schiff base reacting salicylaldehyde and aspartic acid, glutamic acid, p-aminobenzoic acid, glycin acid, p-aminobene sulfonic acid, o- aminobenzoic acid, p-aminobenzoic acid and taurine.The third part is results and discussions part. The compound in the second part were characterized by elemental analysis, FT-IR, Raman spectroscopy. Some of the compounds were also characterized by X-ray power diffraction. Moreover, the single crystals of Rb[(H₂Ssal)(H₂O)] and Rb2[(HSsal)(2H₂O)] were obtained and the structure were determined by X-ray single crystal diffraction method. The results indicate that two compounds both were monoclinic system, space group P2(l)/c, for Rb[(H₂Ssal)(H₂O)] (T=273(2) K), a=1.1779(11) nm, b=0.7363(7) nm, c=1.2025(l 1) nm, β=103.359(12)°, V= 1.0147(16) nm3, Z= 4, Dx = 2.099 Mg.m-3, F(000) = 632, and for Rb₂[(HSsal)(2H₂O)](T=298(2) K), a = 0.97299(18) nm, b = 2.0596(3) nm, c = 0.61911(14) nm, p=90.452(3)°, V= 1.2406(4) nm3, Z = 4, Dx = 2.265 Mg.m-3, F(000) = 816. The two compounds have different coordination numbers of rubidium both with Rb-0 distance from 0.2802(7) to 0.3468(5) nm. The coordination number for the former one is 8, and 8 and 9 for the later one. The bulk structure of the two compounds is a stacking of sandwiches in which the layer contains all polar units while the periphery is made up of the aromatic rings.The synthetic processes of the Schiff base (salicylaldehyde-amino acid) rubidium compounds were special because of the nitrogen protecting environment. And the reacting process of the rubidium compounds of Schiff base (reacting by salicylaldehyde with o- aminobenzoic acid, p-aminobenzoic acid and p-aminobene sulfonic acid) must...