Abstract
Full Text
PHYSICAL CHEMISTRY
M. I. Shakhparonov, S. L. Lelchuk, and K. M. Korchemskaya
THERMODYNAMIC PROPERTIES OF SOLUTIONS OF CHLOROSILANE DERIVATIVES
(Presented by Academician V. I. Spitsyn, April 4, 1960)
Chlorosilane derivatives, as is known, are among the principal intermediates in the laboratory and industrial synthesis of organosilicon polymers. A systematic study of the thermodynamic properties of solutions of these substances is of substantial practical and theoretical importance. In the present communication we give the main results of investigations of the pressure (P) and density (\gamma) of saturated vapors of the following systems: CH(_3)SiHCl(_2)—SiCl(_4); SiHCl(_3)—C(_6)H(_6); CH(_3)SiCl(_3)—SiCl(_4), (CH(_3))(_3)SiCl—CH(_3)SiHCl(_2), (CH(_3))(_3)SiCl—CH(_3)SiCl(_3), as well as solutions of CH(_3)SiHCl(_2) and CH(_3)SiCl(_3) in an azeotropic mixture containing 45.93 mole % (CH(_3))(_3)SiCl and 54.07 mole % SiCl(_4).
The method for measuring (P) and (\gamma) is described in ((^{1})). After chemical purification and rectification, the individual liquid components had the following densities (d^{20}{4}) and boiling points at 760 mm Hg: SiHCl(_3): (d^{20}) 1.3451 and b.p. 31.9°; C(6)H(_6): (d^{20}) 0.8787 and b.p. 80.1°; CH(3)SiHCl(_2): (d^{20}) 1.1049 and b.p. 41.1°; (CH(3))(_3)SiCl: (d^{20}) 0.858 and b.p. 57.6°; SiCl(4): (d^{20}) 1.483 and b.p. 56.8°; CH(3)SiCl(_3): (d^{20}) 1.2770 and b.p. 65.9°.
Table 1
Constants of the Antoine equation
| System | (X_1) | (A) | (B) | (C) |
|---|---|---|---|---|
| CH(_3)SiHCl(_2)(1)—(CH(_3))(_3)SiCl(2) | 1.000 | 19.6410 | 18222.2 | 1046.2 |
| CH(_3)SiHCl(_2)(1)—(CH(_3))(_3)SiCl(2) | 0.900 | 4.1838 | 116.03 | 46.72 |
| CH(_3)SiHCl(_2)(1)—(CH(_3))(_3)SiCl(2) | 0.500 | 8.9130 | 2390.0 | 347.7 |
| CH(_3)SiHCl(_2)(1)—(CH(_3))(_3)SiCl(2) | 0.216 | 8.4039 | 2153.5 | 336.1 |
| CH(_3)SiHCl(_2)(1)—(CH(_3))(_3)SiCl(2) | 0.100 | 6.7000 | 1036.2 | 215.0 |
| CH(_3)SiHCl(_2)(1)—(CH(_3))(_3)SiCl(2) | 0.000 | 6.2424 | 829.4 | 188.6 |
| SiHCl(_3)(1)—C(_6)H(_6)(2) | 1.000 | 4.5403 | 188.85 | 81.79 |
| SiHCl(_3)(1)—C(_6)H(_6)(2) | 0.900 | 5.9874 | 669.1 | 180.6 |
| SiHCl(_3)(1)—C(_6)H(_6)(2) | 0.640 | 7.0797 | 1280.32 | 262.9 |
| SiHCl(_3)(1)—C(_6)H(_6)(2) | 0.4995 | 5.8792 | 684.14 | 180.53 |
| SiHCl(_3)(1)—C(_6)H(_6)(2) | 0.300 | 7.6490 | 1757.6 | 311.7 |
| SiHCl(_3)(1)—C(_6)H(_6)(2) | 0.230 | 5.4023 | 523.72 | 146.55 |
| CH(_3)SiHCl(_2)(1)—SiCl(_4)(2) | 0.895 | 6.4484 | 887.76 | 206.45 |
| CH(_3)SiHCl(_2)(1)—SiCl(_4)(2) | 0.690 | 8.3908 | 2103.5 | 337.3 |
| CH(_3)SiHCl(_2)(1)—SiCl(_4)(2) | 0.495 | 9.7062 | 3204.5 | 422.8 |
| CH(_3)SiHCl(_2)(1)—SiCl(_4)(2) | 0.200 | 8.6719 | 2369.5 | 356.9 |
| CH(_3)SiHCl(_2)(1)—SiCl(_4)(2) | 0.060 | 7.5487 | 1572.95 | 281.63 |
| CH(_3)SiHCl(_2)(1)—SiCl(_4)(2) | 0.000 | 7.4042 | 1442.8 | 261.7 |
| CH(_3)SiCl(_3)(1)—(CH(_3))(_3)SiCl(2) | 1.000 | 8.6655 | 2380.6 | 345.16 |
| CH(_3)SiCl(_3)(1)—(CH(_3))(_3)SiCl(2) | 0.850 | 8.5799 | 2324.9 | 343.17 |
| CH(_3)SiCl(_3)(1)—(CH(_3))(_3)SiCl(2) | 0.532 | 9.7555 | 3371.9 | 428.20 |
| CH(_3)SiCl(_3)(1)—(CH(_3))(_3)SiCl(2) | 0.150 | 8.12392 | 2057.4 | 324.50 |
| CH(_3)SiCl(_3)(1)—SiCl(_4)(2) | 0.900 | 7.8405 | 1774.6 | 293.2 |
| CH(_3)SiCl(_3)(1)—SiCl(_4)(2) | 0.600 | 9.2407 | 2877.7 | 391.27 |
| CH(_3)SiCl(_3)(1)—SiCl(_4)(2) | 0.300 | 13.0808 | 7291.1 | 656.1 |
| CH(_3)SiCl(_3)(1)—SiCl(_4)(2) | 0.100 | 7.0783 | 1274.9 | 245.4 |
| Azeotrope (1)—CH(_3)SiHCl(_2)(2) | 1.000 | 8.4765 | 2210.91 | 340.23 |
| Azeotrope (1)—CH(_3)SiHCl(_2)(2) | 0.950 | 6.3505 | 847.59 | 197.91 |
| Azeotrope (1)—CH(_3)SiHCl(_2)(2) | 0.500 | 22.3568 | 26090.1 | 1292.9 |
| Azeotrope (1)—CH(_3)SiHCl(_2)(2) | 0.050 | 6.2535 | 793.8 | 193.48 |
| Azeotrope (1)—CH(_3)SiCl(_3)(2) | 0.900 | 8.5736 | 2449.2 | 361.6 |
| Azeotrope (1)—CH(_3)SiCl(_3)(2) | 0.500 | 9.8962 | 3458.1 | 432.9 |
| Azeotrope (1)—CH(_3)SiCl(_3)(2) | 0.208 | 7.8291 | 1790.65 | 298.06 |
Table 1 contains the values of the constants of the Antoine equations
[
\lg P = A - B(C + T),
]
calculated from experimental data on the pressure (P) of the individual components and their solutions.
Fig. 1
Fig. 2
Fig. 3
Using the equation (\overline{M} = \gamma RT/P), the average molecular weight of the saturated vapors was calculated, and then their composition was determined from the formula (\overline{M} = \sum_i M_i x'_i). In parallel, the partial pressures (P_i) of the component vapors were calculated. The values of (P_i) and (x'_i) were independently checked by the conditions of thermodynamic consistency, which made it possible to find these quantities with an accuracy of 1–2%.
Fig. 1 shows the dependence of the total and partial vapor pressures of the (\mathrm{SiHCl_3}—\mathrm{C_6H_6}) system on the composition of the solutions at (30^\circ).
Fig. 2 presents the isotherm (P) and (P_i) of the (\mathrm{CH_3SiHCl_2}—\mathrm{SiCl_4}) system at (40^\circ) and of the (\mathrm{CH_3SiCl_3}—\mathrm{SiCl_4}) system at (50^\circ).
It follows from Figs. 1 and 2 that the indicated solutions are characterized by small positive deviations from ideality.
Solutions ((\mathrm{CH_3})_3\mathrm{SiCl}—\mathrm{CH_3SiCl_3}), (\mathrm{CH_3SiHCl_2}—(\mathrm{CH_3})_3\mathrm{SiCl}), azeotrope—(\mathrm{CH_3SiCl_3}), and azeotrope—(\mathrm{CH_3SiHCl_2}), within the limits of the accuracy of our measurements (1–2%), obey Raoult’s law over the entire concentration range. Fig. 3 shows the isobars of the solutions investigated by us at (P = 760) mm.
Moscow State University
named after M. V. Lomonosov
Received
2 IV 1960
REFERENCES CITED
- M. I. Shakhparonov, E. A. Balamutova et al., ZhFKh. (1960).