Trinitrobenzene

Structural formula
General
Surname	Trinitrobenzene
other names	1,3,5-trinitrobenzene; TNB; Trinitrobenzene; sym- trinitrobenzene; Benzite; RC; RA;
Molecular formula	C 6 H 3 N 3 O 6
Brief description	colorless rhombic-bipyramidal leaflets
External identifiers / databases
EC number	202-752-7
ECHA InfoCard	100.002.502
PubChem	7434
Wikidata	Q420320
properties
Molar mass	213.11 g mol −1
Physical state	firmly
density	1.76 g cm −3 (20 ° C)
Melting point	125.3 ° C (polymorph I); 107.2 ° C (polymorph II); 109.8 ° C (polymorph III);
boiling point	315 ° C
solubility	very bad in water (330 mg l −1 at 20 ° C); poor in ethanol , diethyl ether and benzene ;
safety instructions
H and P phrases	H: 201-300-310-330-373-410
	P: 260-264-273-280-284-301 + 310
Toxicological data	275 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Trinitrobenzene ( TNB ) is an explosive . The explosive power of TNB is comparable to that of TNT . Despite a slightly higher explosive power than TNT, TNB is not used for economic reasons. It consists of a benzene ring with three nitro groups (–NO ₂ ) as substituents. There are three constitutional isomers of TNB (1,2,3-, 1,2,4- and 1,3,5-trinitrobenzene), but the abbreviation is mostly used for the 1,3,5-isomer.

presentation

The preparation of trinitrobenzene is carried out by nitration of m-dinitrobenzene with a mixture of fuming nitric acid and concentrated sulfuric acid. The preparation from 2,4,6-trinitrotoluene is also possible, with decarboxylation in boiling water following an oxidation to 2,4,6-trinitrobenzoic acid with potassium dichromate and sulfuric acid .

properties

Trinitrobenzene occurs in five polymorphic forms. The thermodynamically stable form I melts at 125.3 ° C with a melting enthalpy of 15.0 kJ mol ⁻¹ . The metastable form II and III show melting points at 107.2 ° C and 109.8 ° C with heats of fusion of 14.8 kJ · mol ^-1 and 13.2 kJ · mol ^-1 . Both forms are monotropic to form I. Forms II and III are enantiotropic to one another. The transition point between Form II and III is around 97 ° C. Two other forms with melting points at 109 ° C and 88 ° C could only be observed with a thermomicroscope.

The compound is resistant to acids and reacts with bases. It is insoluble in water, slightly soluble in alcohol, ether and benzene, well soluble in acetone or ethyl acetate. With polycyclic aromatic hydrocarbons such as naphthalene , anthracene and carbazole are charge-transfer complex formed. The stoichiometric 1: 1 complexes show defined melting points, such as with naphthalene at 157.6 ° C, with anthracene at 165.4 ° C and with carbazole at 204.4 ° C.

The compound surpasses trinitrotoluene in terms of explosive power. Important explosion indicators are:

Educational energy	−134.5 kJ kg ⁻¹
Enthalpy of formation	−204.3 kJ kg ⁻¹
Oxygen balance	−56.3%
Nitrogen content	19.72%
Normal gas volume	939 l kg ⁻¹
Explosion heat	3927 kJ kg ⁻¹ (H ₂ O (l)) 3845 kJ kg ⁻¹ (H ₂ O (g))
Specific energy	1051 kJ kg ⁻¹ (107.1 mt / kg)
Lead block bulge	32.5 cm ³ g ⁻¹
Detonation velocity	7300 m · s ⁻¹ at a density of 1.6 g · cm ⁻³
Sensitivity to impact	7.4 Nm
Rubbing sensitivity	no reaction up to 353 N pin load

use

TNB is a little more sensitive to impact than TNT, but this would not be of any consequence when used. Because it is more complex to manufacture, it is significantly more expensive than TNT and is therefore not used in practice.

Individual evidence

↑ ^a ^b entry on 1,3,5-trinitrobenzene. In: Römpp Online . Georg Thieme Verlag, accessed on November 10, 2014.
↑ ^a ^b ^c ^d ^e ^f Entry on 1,3,5-trinitrobenzene in the GESTIS substance database of the IFA , accessed on February 3, 2018(JavaScript required) .
↑ ^a ^b ^c ^d ^e M. Radomska; R. Radomski: Calorimetric studies of binary systems of 1,3,5-trinitrobenzene with naphthalene, anthracene and carbazole. I. Phase transitions and heat capacities of the pure components and charge-transfer complexes , in: Thermochim. Acta , 40 (1980), pp. 405-424 ( doi : 10.1016 / 0040-6031 (80) 80082-7 ).
↑ Entry on 1,3,5-trinitrobenzene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l J. Köhler, R. Meyer, A. Homburg: Explosivstoffe , 10th completely revised edition, Wiley-VCH, Weinheim 2008, p. 330, ISBN 978-3-527 -32009-7 .
↑ HT Clarke, WW Hartman: 2,4,6-Trinitrobenzoic Acid In: Organic Syntheses . 2, 1922, p. 95, doi : 10.15227 / orgsyn.002.0095 ; Coll. Vol. 1, 1941, p. 543 ( PDF ).
↑ HT Clarke, WW Hartman: 1,3,5-Trinitrobenzene In: Organic Syntheses . 2, 1922, p. 93, doi : 10.15227 / orgsyn.002.0093 ; Coll. Vol. 1, 1941, p. 541 ( PDF ).
↑ A. Koffler; M. Brandstätter: On the isomorphic justifiability of H, OH, Cl: s-trinitrobenzene, picric acid, picryl chloride , in: Monatshefte für Chemie , 1948 , 78 , pp. 65–70 ( doi : 10.1007 / BF00942489 ).

[roempp-1] try on 1,3,5-trinitrobenzene. In: Römpp Online . Georg Thieme Verlag, accessed on November 10, 2014.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f Entry on 1,3,5-trinitrobenzene in the GESTIS substance database of the IFA , accessed on February 3, 2018(JavaScript required) .

[Radomska-3] M. Radomska; R. Radomski: Calorimetric studies of binary systems of 1,3,5-trinitrobenzene with naphthalene, anthracene and carbazole. I. Phase transitions and heat capacities of the pure components and charge-transfer complexes , in: Thermochim. Acta , 40 (1980), pp. 405-424 ( doi : 10.1016 / 0040-6031 (80) 80082-7 ).

[CLP_100.002.502-4] Entry on 1,3,5-trinitrobenzene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[Explosivstoffe-5] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l J. Köhler, R. Meyer, A. Homburg: Explosivstoffe , 10th completely revised edition, Wiley-VCH, Weinheim 2008, p. 330, ISBN 978-3-527 -32009-7 .

[6] HT Clarke, WW Hartman: 2,4,6-Trinitrobenzoic Acid In: Organic Syntheses . 2, 1922, p. 95, doi : 10.15227 / orgsyn.002.0095 ; Coll. Vol. 1, 1941, p. 543 ( PDF ).

[7] HT Clarke, WW Hartman: 1,3,5-Trinitrobenzene In: Organic Syntheses . 2, 1922, p. 93, doi : 10.15227 / orgsyn.002.0093 ; Coll. Vol. 1, 1941, p. 541 ( PDF ).

[8] A. Koffler; M. Brandstätter: On the isomorphic justifiability of H, OH, Cl: s-trinitrobenzene, picric acid, picryl chloride , in: Monatshefte für Chemie , 1948 , 78 , pp. 65–70 ( doi : 10.1007 / BF00942489 ).