Detail of "690-39-1"

Reference

Vapor pressure measurements of 1,1,1-trifluoroethane (HFC-143a) and 1,1,1,3,3,3-hexafluoropropane (HFC-236fa)

Vapor pressure measurements of 1,1,1-trifluoroethane (HFC-143a) and 1,1,1,3,3,3-hexafluoropropane (HFC-236fa). Duan, Yuan-Yuan; Wang, Zhong-Wei; Meng, Long; Sun, Xiao-Yang ( Department of Thermal Engineering, Key Laboratory of Thermal Science and Power Engineering, Tsinghua University, Beijing 100084, Peop. Rep. China). Fluid Phase Equilibria, 225(1-2), 101-106 (English) 2004 Elsevier B.V. CODEN: FPEQDT. ISSN: 0378-3812. DOCUMENT TYPE: Journal CA Section: 65 (General Physical Chemistry) Section cross-reference(s): 68 The vapor pressures of 1,1,1-trifluoroethane (HFC-143a) and 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) were measured with a modified Burnett app. The vapor pressures were measured at temps. from 251 to 343 K and pressures from 292 to 3553 kPa for HFC-143a, and at temps.Several substances with their cas registry numbers 690-39-1 and 420-46-2 may be metioned in this study. from 253 to 396 K and pressures from 43 to 3064 kPa for HFC-236fa. The measurement uncertainties were estd. to be within ± 10 mK and ± 1.2 kPa. Two vapor pressure equations were developed to represent the exptl. data for HFC-143a and HFC-236fa, resp. The results were also compared with available literature data. .

Molecular-mechanics calculations for H2C(CX3)2, X2C(CX3)2, H2Si(CX3)2 and X2Si(CX3)2 molecules with X = F, Cl and Br

Molecular-mechanics calculations for H2C(CX3)2, X2C(CX3)2, H2Si(CX3)2 and X2Si(CX3)2 molecules with X = F, Cl and Br. Stolevik, Reidar; Bakken, Pirkko (Dep. Chem., Univ. Trondheim, Dragvoll N-7055, Norway). J. Mol. Struct., 145(3-4), 287-95 (English) 1986. CODEN: JMOSB4. ISSN: 0022-2860. 690-39-1 and 76-19-7 which are cas registry numbers are also used here. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) The title calcns. predict that the stable conformation for H2C(CX3)2 and H2Si(CX3)2 (X = Br, Cl) is C2. The torsional potential has a double min. with a barrier between two enantiomeric forms. The barrier heights are in the 0.5-1.5 kcal/mol range. For the remaining mols., the stable conformer is C2v. .