Picrate
Apicrateis asaltcontaining the anion (O2N)3C6H2O−or anesterderivative of the picrate anion. These salts are often produced by reactions ofpicric acid(2,4,6-trinitrophenol).[1][2]The picrate ion is intensely yellow, although many of its salts are brown or orange-red.
Explosives
[edit]Many picrates areexplosives,for exampleammonium picrate(known asDunnite). Some are used as primary explosives, namelylead picrateorpotassium picratewhich find their use asprimersfor cartridgeammunition.Picrates of some metals tend to be significantly more sensitive to impact, friction and shock than picric acid itself. As a result, storage of picric acid (or mixtures containing it) in metal containers is strongly discouraged due to the high risk of accidental explosion.
Other uses
[edit]Ferrous picrateis used in some applications as a dieselfuel additiveto achieve bettermileage.[3]
Sodium picrate is used as an etchant inmetallographyto differ preeutectoidferritein hypoeutectoid steel from preeutectoidcementitein hypereutectoid steel byetchingcementite to a dark colour, whereas not attacking ferrite and thus it remains reflective.
Ethers and esters of picric acid are also called picrates. The ether methyl picrate (CAS# 606-35-9) has the formula (O2N)3C6H2OCH3.
References
[edit]- ^Olsher, Uriel; Feinberg, Hadar; Frolow, Felix; Shoham, Gil (1996)."The picrate anion as a versatile chelating counterion for the complexation of alkali and alkaline earth metal cations with ionophores: 'the picrate effect'".Pure and Applied Chemistry.68(6): 1195–1199.doi:10.1351/pac199668061195.S2CID96529554.
- ^ Smith, M. B.; March, J. (2007).March's Advanced Organic Chemistry(6th ed.). John Wiley & Sons. p. 118.ISBN978-0-471-72091-1.
- ^Zhu, Mingming; Ma, Yu; Zhang, Dongke (2012). "Effect of a homogeneous combustion catalyst on the combustion characteristics and fuel efficiency in a diesel engine".Applied Energy.91:166–172.doi:10.1016/j.apenergy.2011.09.007.