Thermal properties, phase transitions, vibrational and reorientational dynamics of [Mn(NH3)6](NO3)2

Majda

2012

Self Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Thermal decomposition of polycrystalline [Ni(NH3)6](NO3)2

Mikuli

Majda

2012

Self Cite

show abstract

“…These assignments proved that the composition and structure of the investigated compound are correct. Detailed description and analysis of vibrational modes can be found in Mikuli et al [20]. Figure 8 shows exemplarily the spectra in the wavenumber ranges: 4000-3040, 1840-1500 and 1300-500 cm -1 , at selected temperatures of measurement.…”

Section: Resultsmentioning

confidence: 99%

Thermal properties of polycrystalline [Mn(NH3)6](ClO4)2

Hetmańczyk

et al. 2014

Self Cite

The X-ray powder diffraction (XRPD) pattern of [Mn(NH 3 ) 6 ](ClO 4 ) 2 at room temperature can be indexed in the regular (cubic) system (Fm3m space group) with lattice cell parameter a = 11.5729 Å and with four molecules per unit cell. The XRPD pattern at 100 K is evidently different, and it indicates lowering of the crystal structure. One phase transition at T h C1 = 143.5 K (on heating) and at T c C1 = 137.6 K (on cooling) was detected by DSC for [Mn(NH 3 ) 6 ](ClO 4 ) 2 in the range of 120-300 K. The following thermodynamic parameters for phase I $ phase II transition were obtained: DH = 3.1 ± 0.2 kJ mol -1 and DS = 21.6 ± 0.3 J mol -1 K -1 . The large value of entropy changes (DS) indicates considerable configurational disorder in the high temperature phase. The presence of 5.9 K hysteresis of the phase transition temperature at T C and sharpness of the heat flow anomaly attest that the detected phase transition is of the first-order type. Appearing of the two new bands (splitting of d s (HNH)F 1u mode) in FT-MIR spectra at the vicinity of 1200 cm -1 suggests that the phase transition undergoes a change of the crystal structure.

show abstract

Phase polymorphism and thermal decomposition of hexadimethylsulphoxidemagnesium(II) chlorate(VII)

Szostak

2010