Nitroglycerin (C₃H₅N₃O₉) — Properties, Uses & Safety

Overview

Nitroglycerin (C3H5N3O9), also known as glyceryl trinitrate, is a colorless to pale yellow oily liquid with a molar mass of 227.09 g/mol. Its IUPAC name, 1,3-bis(nitrooxy)propan-2-yl nitrate, reveals that it is a nitrate ester — glycerol with all three hydroxyl groups esterified with nitric acid. Nitroglycerin is one of the most powerful and sensitive conventional explosives known, capable of detonating from relatively minor shock, heat, or friction. This extreme sensitivity made it notoriously dangerous to manufacture and transport in the 19th century, leading to numerous fatal accidents. Alfred Nobel's invention of dynamite in 1867 — nitroglycerin absorbed into diatomaceous earth — tamed this sensitivity and revolutionized construction, mining, and unfortunately warfare. The profits from dynamite funded the Nobel Prizes. GHS hazard codes include H201 (explosive, mass explosion hazard), H330 (fatal if inhaled), and H373 (may cause organ damage). The explosive decomposition of nitroglycerin (4 C3H5N3O9 -> 12 CO2 + 10 H2O + 6 N2 + O2) is remarkably exothermic and produces only gaseous products, explaining its devastating power — the rapid expansion of hot gases creates the blast wave. Remarkably, nitroglycerin also has life-saving medical applications. At very low doses, it is a vasodilator used to treat angina pectoris (chest pain from reduced blood flow to the heart) and heart failure. It works by releasing nitric oxide (NO), which relaxes smooth muscle in blood vessel walls. This dual identity — deadly explosive and cardiac medication — makes nitroglycerin one of chemistry's most fascinating compounds. For chemistry students, nitroglycerin connects to esterification reactions, thermochemistry and enthalpy of decomposition, the relationship between molecular structure and sensitivity in energetic materials, and the surprising intersection of explosives chemistry with pharmacology.

IUPAC Name

1,3-bis(nitrooxy)propan-2-yl nitrate

CAS Number

55-63-0

PubChem CID

4510

Molecular Formula

C₃H₅N₃O₉

Molar Mass

227.086 g/mol

State at STP

liquid

Appearance

Colorless to pale yellow oily liquid