Dimethylamine-borane (1:1)

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Effusion method: Knudsen cell
The vaporization chamber consisted of a small monel cylinder with an i.d. of 15 mm and a depth of 20 mm. It was fitted with an open cap at the top which compressed the platinum sheet containing the orifice between two thin copper gaskets to complete the closure. The orifices were carefully drilled, inspected under the microscope for imperfections and burrs and their diameters measured by a comparator. The two used had diameters of 0.0374 and 0.0776 cm and ratios of thickness to radius of 0.183 and 0.313, respectively.
Effusion took place from the chamber into a vacuum of approximately 10^-5 mm of Hg, a surface maintained at liquid nitrogen temperature some 8 cm above the orifice trapping most of the effused material. The vaporization chamber was recessed into a closely fitting 0.8 kg block of copper to provide a large thermal reservoir and the latter was enclosed by a double walled section of the vacuum system through which constant temperature water was circulated. The temperature of the copper block immediately adjacent to the vaporization chamber was monitored by a copper-constantan thermocouple. In general, the loss in weight per run was of the order of 10-50 mg.

GLP compliance:

no

Type of method:

effusion method: Knudsen cell

Key result

Temp.:

25 °C

Vapour pressure:

0.14 mBar

Remarks on result:

other: Vapour pressure of dimethylamine-borane (1:1) at 25°C was calculated with the following experimentally obtained equation (validity range: 0 - 35 °C): log P (mmHg) = - [4038 * (1 +- 0.038)] / T + 12.544 (1 +- 0.042)

Conclusions:

The vapour pressure of dimethylamine-borane (1:1) is 0.14 mbar at 25 °C.

Executive summary:

The vapour pressure of dimethylamine-borane (1:1) was experimentally determined by the Knudsen cell effusion method. At 25 °C, the vapour pressure is 0.14 mbar and was calculated with the following experimentally obtained equation (validity range: 0 - 35 °C): log P (mmHg) = - [4034 * (1 +- 0.038)] / T + 12.544 (1 +- 0.042).

Description of key information

Key study: Experimental study using Knudsen cell effusion method. The vapour pressure of the test item is 0.14 mbar at 25ºC.

Key value for chemical safety assessment

Vapour pressure:

14 Pa

at the temperature of:

25 °C