INDUSTRIAL AND ENGINEERING CHEMISTRY
1094
' C Atoms
-
1 mm.
... ... ...
6
7 S
...
9 10 11 12 13 14 15 16 17 18 e
56.3 69.0 81.4 97.0 109.2 120.6 131.8 143.2 153.2
VOL. 32, NO. 8
TABLE 11. BOILING POINTS OF %ALKYLPRIMARY AMINES 2mm.
4mm.
8mm.
...
...
... ...
...
35.2
46.6
58.9
51.5
62.9 78.4 91.9 106.3 120.8 133.6 146.5 157.6 168.6 180.0
75.6 91.2 105.1 120.5 134.9 147.8 160.1 172.7 183.9 195.5
66.9 80.3 93.5 108.0 120.9 132.3 143.9 155.0 166.1
...
16 mm.
...
Boiling Points, in 32 mm. 64 a m .
O
C., a t Following Pressure: 128 mm. 2 5 6 m m . 5 1 2 m m . 760 mm.
62.5 81.8
79.1 99.8
72.1
86.6
102.8
121.1
141.5
164.9
179.6
177.6
89.4 105.6 120.0 135.2 150.6 163.4 176.3 189.4 200.6 212.3
104.8 121.4 136.7 152.3 167.8 181.4 194.6 207.9 219.3 232.0
122.2 138.8 155.3 171.2 186.7 201.1 214.5 228.2 239.7
141.2 158.3 175.7 191.8 207.4 222.9 236.9 250.7 262.3
162.5 180.2 198.4 214.9 230.9 246.6 261.7 275.8 288.1
187.3 204.9 224.9 242.1 258.2 274.2 289.7 304.6 317.6
202.2 220.5 241.6 259.1 275.7 291.2 307.6 322.5 335.9 348.8'
198.9 219.0 238.1 256.4 273.8 290.5 306.6 322.0 337.0 351.4
...
...
98.1 119.7
...
119.4 143.4
...
132.7 156.9
Calcd.
47.7 67.3
53.8
130.8 155.0
Literature 128-30 ( 6 ) , 129 (7) 153-5 ( 6 ) , 155.20 (16), 153 (14) 171-4 ( B ) , 175-7 ( 1 3 ) 179-80 (81, 185-7 (6) 195 (61, 2 0 1 ( 1 ) 202-3 ( 1 7 ) . 216-18 (4) 233 (41, 234 (8) 247-9 (18) 265 (18)
........
298-301 (9),299-301($) 330 ( I f ) 322-4 (Z), 335-340 (16)
........
To avoid thermal decomposition, this boiling point was determined on a fresh sample a8 rapidly as possible.
prevent contact with the mercury. The error in reading the potentiometer did not exceed 0.2" C., and prior to each run the thermocouple was cheBked against B thermometer calibrated a t the National Bureau of Standards.
:&E.
;
4,8 . . . . 512, and 760 mm. were then interpolated from these curves. These values are shown in Table 11, which also contains the boiling points at 760 rnm. calculated from the empirical equation developed by Kinney (IO). The boiling points shown in Table I1 were used for the construction of the curves shown in Fig, ure 2. The boiling points obtained a t 760 mm. are approximately 2" C. higher than the calculated values. This relation does not hold for hexadecyl and higher amines, owing to a slight thermal decomposition of these compounds at high temperatures. When plotted against the reciprocals of the boiling points, the logarithms of the pressures give slightly curved lines. This indicated a slight association of the primary amines in the liquid state. The authors consider all the boiling points shown in Table I1 to be within 2" C. of the true boiling points and most of them to be considerably within this value. The possible exceptions are the boiling points of the three highest members a t 760 mm. pressure.
Literature Cited
%URVESO F NORMAL PRIMARY ALIPHATIC FIGURE 2. VAPORPRES~$W AMINES Curve numbers refer to number of carbon atoms in the molecule. To make a determination, 10 cc. of amine were introduced into the apparatus a t B , which was then sealed. The system was evacuated and the flask heated by an electric heater or, in some cases, by a microburner. Equilibrium was considered to have been attained whep the temperature at E,remained constant over a period of several minutes, after hhich time the temperature and pressure were recorded. The pressure was then increased and this procedure was duplicated until the final reading a t atmospheric pressure was obtained; then the boiling point a t the initial pressure was redetermined in order to ascertain whether any decompositlon had occurred. The vacuum pump was used only tooevacuate the system to the initial low pressure and was never in operation while the boiling twperatures were being read. ;
Results For each amine the logarithms of the pressures were plotted against the reciprocds
