Boron trichloride

Structural formula
General
Surname	Boron trichloride
other names	Boron chloride; Trichloroborane;
Molecular formula	BCl 3
Brief description	colorless gas
External identifiers / databases
EC number	233-658-4
ECHA InfoCard	100.030.586
PubChem	25135
ChemSpider	23480
Wikidata	Q415872
properties
Molar mass	117.17 g mol −1
Physical state	gaseous
density	5.252 g l −1 gas density under normal conditions (0 ° C, 1013 mbar); 1.346 kg · l −1 of the liquid phase at the boiling point;
Melting point	−107.2 ° C
boiling point	12.5 ° C
Vapor pressure	160 k Pa (20 ° C)
solubility	Decomposes in water
safety instructions
H and P phrases	H: 330-314-280-300
	EUH: 014-071
	P: 260-280-304 + 340-303 + 361 + 353-305 + 351 + 338-315-405-403
Thermodynamic properties
ΔH f 0	−403.8 kJ / mol
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Boron trichloride is a gaseous chemical compound from the group of boron - halogen compounds or inorganic chlorine compounds .

Extraction and presentation

Boron trichloride is obtained industrially by the direct chlorination of boron trioxide and carbon at 500 ° C.

{\ displaystyle \ mathrm {B_ {2} O_ {3} +3 \ C + 3 \ Cl_ {2} \ rightarrow 2 \ BCl_ {3} +3 \ CO}}

This synthesis is analogous to the Kroll process .

Alternatively, the synthesis directly from boric acid via the intermediate step of triphenyl borate is also possible.

{\ displaystyle \ mathrm {B (C_ {6} H_ {5} O) _ {3} + AlCl_ {3} \ rightarrow BCl_ {3} + Al (C_ {6} H_ {5} O) _ {3} }}

A direct synthesis from the elements boron and chlorine is also possible.

To produce small amounts of very pure boron trichloride in the laboratory, the gaseous compound boron trifluoride is reacted with anhydrous aluminum chloride

{\ displaystyle {\ ce {BF3 + AlCl3 -> AlF3 + BCl3}}}

Alternatively, a mixture of potassium tetrafluoroborate with aluminum chloride can be heated for several hours to generate the gaseous compound. However, this should then be subjected to a fractional distillation for purification

{\ displaystyle {\ ce {KBF4 + AlCl3 -> AlF3 + KF + BCl3}}}

properties

Boron trichloride is an incombustible, colorless gas that fumes heavily in moist air due to the formation of hydrogen chloride mist.

On contact with water it reacts violently with the formation of hydrochloric acid and boric acid :

{\ displaystyle \ mathrm {BCl_ {3} +3 \ H_ {2} O \ \ rightleftharpoons \ B (OH) _ {3} +3 \ HCl}}

The critical point is 178.8 ° C, 38.7 bar and 0.790 kg / l; the triple point at −107 ° C and 0.373 mbar. Boron trichloride is a Lewis acid and reacts easily with tertiary amines , phosphines , ethers , thioethers and halide ions. It has a heat of vaporization of 203 kJ / kg, specific heat capacity of 0.5345 kJ / (kg · K) and a thermal conductivity of 110 · 10 ⁻⁴ W / (m · K) (as a gas at 25 ° C and 1 bar pressure ).

use

Boron trichloride is used as catalyst , for the synthesis of other chemical compounds (eg. B. borazine ), for chlorination , for the removal of nitrides , carbides and oxides of melting of aluminum, magnesium, tin and copper alloys as well as for doping of semiconductors used.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Entry on boron trichloride in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

↑ Entry on boron trichloride in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-5.

↑ ^a ^b Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 .

^ ^A ^b E. Lee Gamble: Boron chloride and bromide . In: Ludwig F. Audrieth (Ed.): Inorganic Syntheses . tape 3 . McGraw-Hill, Inc., 1950, pp. 27-30 (English).

^ W. Gerrard, MF Lappert: Reactions Of Boron richloride With Organic Compounds. In: Chemical Reviews . Vol. 58, No. 6, 1958, pp. 1081-1111, doi : 10.1021 / cr50024a003 .

↑ Data sheet (knife) ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 254 kB).@1@ 2

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Entry on boron trichloride in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[CLP_100.030.586-2] Entry on boron trichloride in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[CRC90_5_5-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-5.

[Brauer-4] Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 .

[IS3-5] A ^b E. Lee Gamble: Boron chloride and bromide . In: Ludwig F. Audrieth (Ed.): Inorganic Syntheses . tape 3 . McGraw-Hill, Inc., 1950, pp. 27-30 (English).

[6] W. Gerrard, MF Lappert: Reactions Of Boron richloride With Organic Compounds. In: Chemical Reviews . Vol. 58, No. 6, 1958, pp. 1081-1111, doi : 10.1021 / cr50024a003 .