Clathrate formation and phase equilibria in the pyridine-cadmium nitrate system |
| |
| Authors: | D. V. Soldatov Yu. A. Dyadin E. A. Ukraintseva B. A. Kolesov V. A. Logvinenko |
| |
| Affiliation: | (1) Institute of Inorganic Chemistry, Russian Academy of Sciences, Siberian Branch, 630090 Novosibirsk, Lavrentyeva 3, Russia |
| |
| Abstract: | ![]()
Preparative, thermal (DTA, TGA), solubility, strain and spectral (Raman) techniques were used to study clathrate and complex formation in the pyridine (Py)-cadmium nitrate system. Three compounds have been isolated and studied: the clathrate compound [CdPy4(NO3)2] · 2Py (I), the complex [CdPy3(NO3)2] (II) and a compound of composition  Cd(NO3)2·7/4Py (III), of unknown nature. The phase diagram of the system has been determined for the concentration and temperature range 0–66 mass-% Cd(NO3)2 and –100 to +200 °C, respectively. ClathrateI undergoes polymorphous conversion at –51.8(4) °C and melts incongruently at 106.0(5) °C, forming complexII. CompoundsII andIII melt congruently at 165.5(4) and 191(1) °C, respectively. The complexes [CdPy4(NO3)2] (the host phase) and [CdPy2(NO3)2] are not observed in the system. The nature and thermodynamic parameters of the dissociation of clathrate I have been determined. For the process 1/13[CdPy4)NO3)2] · 2Pysolid = 1/3[CdPy3(NO3)2]solid + Pygas in the range 290–360K  Ho = 54.9(3) kj/mole,  S298o = 142(1) J/(mole K), G298o = 12.5(5) kJ/mole. |
| |
| Keywords: | phase diagram vapour pressure thermal analysis clathrate, pyridine |
| 本文献已被 SpringerLink 等数据库收录！ |
|
