Aldrin

Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called 'classic organochlorines' (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after The Second World War. Other noteworthy examples of COCs include DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related 'cyclodiene' pesticides (a term for pesticides derived from Hexachlorocyclopentadiene) became notorious as persistent organic pollutants. Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called 'classic organochlorines' (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after The Second World War. Other noteworthy examples of COCs include DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related 'cyclodiene' pesticides (a term for pesticides derived from Hexachlorocyclopentadiene) became notorious as persistent organic pollutants. The structure formula of aldrin is C12H8Cl6. The molecule has a molecular weight of 364.896 g/mol. The melting point of aldrin is a temperature of 105 °C and the octanol-water partition coefficient is 6.5 (logP). Pure aldrin takes form as a white crystalline powder. Though it is not soluble in water (0.003%% solubility), aldrin dissolves very well in organic solvents, such as ketones and parrafins. Aldrin decays very slowly once released into the environment. Though it is rapidly converted to dieldrin by plants and bacteria, dieldrin maintains the same toxic effects and slow decay of aldrin. Aldrin is easily transported through the air by dust particles. Aldrin does not react with mild acids or bases and is stable in an environment with a pH between 4 and 8. It is highly flammable when exposed to temperatures above 200 °C In the presence of oxidizing agents aldrin reacts with concentrated acids and phenols. Aldrin is not formed in nature. It is synthesized by combining hexachlorocyclopentadiene with norbornadiene in a Diels-Alder reaction to give the adduct. In 1967, the composition of technical-grade aldrin was reported to consist of 90.5% of hexachlorohexahydrodimethanonaphthalene (HHDN). Similarly, an isomer of aldrin, known as isodrin, is produced by reaction of hexachloronobornadiene with cyclopentadiene. Isodrin is also produced as a byproduct of aldrin synthesis, with technical-grade aldrin containing about 3,5% isodrin. Aldrin is named after the German chemist Kurt Alder, one of the coinventors of this kind of reaction. An estimated 270 million kilograms of aldrin and related cyclodiene pesticides were produced between 1946 and 1976. There are multiple available forms of aldrin. One of these is the isomer isodrin, which cannot be found in nature, but needs to be synthesized like aldrin. When aldrin enters the human body or the environment it is rapidly converted to dieldrin. Degradation by ultraviolet radiation or microbes can convert dieldrin to photodieldrin and aldrin to photoaldrin.