Xylyl-bromide, also known asmethylbenzyl bromide orT-stoff ('substance-T'), is any member or a mixture oforganic chemical compounds with themolecular formulaC6H4(CH3)(CH2Br). The mixture was formerly used as atear gas and has an odor reminiscent of lilac.[1] All members and the mixture are colourless liquids, although commercial or older samples appear yellowish.
Xylyl bromide is an irritant andlachrymatory agent. It has been incorporated inchemical weapons since the early months ofWorld War I. Some commentators say the first use was in August 1914, when the French attacked German soldiers withtear gas grenades,[2][3] but the agent used in that incident was more likely to beethyl bromoacetate, which the French had tested before the war.[4]
The first extensive use of xylyl bromide was the firing by German forces of 18,000 "T-shells" at Russian positions in theBattle of Bolimów in January 1915. The shells were modified 15 cm (6 inch)artillery shells containing an explosive charge and c. 3 kg (7 lb) xylyl bromide. The attack was a complete failure because the winter weather was too cold to permit an effective aerosol, and the agent was either blown back towards the German lines, fell harmlessly to the ground, or was insufficiently concentrated to cause damage. A similar attack atNieuwpoort in March 1915 was also unsuccessful.[4] Nevertheless, because of its ease of manufacture xylyl bromide was widely used in World War I, in particular as a component of the Germans'Weisskreuz (white cross) mixture.
Threeisomers, collectively referred to byCAS registry number 35884-77-6,[5] are:
In the absence of clarification, the name "xylyl bromide" may refer to any one of these isomers or a mixture of all three.