Heterocyclic compounds biocides

Quaternary ammonium compounds biocidal activity mechanism, 1, 401 toxicity, 1, 124 Quaternization heterocyclic compounds reviews, 1, 73 ( )-Quebrach amine synthesis, 1, 490 Queen substance synthesis, 1, 439 4, 777 Quercetin occurrence, 3, 878 pentamethyl ether photolysis, 3, 696 photooxidation, 3, 695 Quercetrin hydrolysis, 3, 878 Quinacetol sulfate as fungicide, 2, 514 Quinacridone, 2,9-dimethyl-, 1, 336 Quinacridone pigments, 1, 335-336 Quinacrine... 

The use of biocides is spread across the whole polymer range, e.g., paints, ropes, textiles, fibres, etc. Many are copper, silver or arsenic compounds and also various heterocyclic compounds, e.g., isothiazolines (which have some structural resemblance to penicillin). 

Heterocyclic compounds are used in coatings rather than moulded plastics. There are water-insoluble polymeric biocides, such as the polystyrene hydantoins (see Structure III). Some of these latter substances can be rendered inactive by reducing agents or even by excessive doses of bacteria, but it is claimed that they can be reactivated by sodium hypochlorite. 

Biocides can be subdivided according to their chemical structure into seven main types inorganic compounds hydrocarbons, halogenated hydrocarbons and nitrocompounds alcohols, phenols and their derivatives aldehydes, ketones, organic acids and their derivatives amines, amine salts and quaternary ammonium compositions metal-organic compositions heterocyclic compounds. The characteristics of the most useful biocides are shown in Table 4. 

P. W. Austin. Heterocyclic thione compounds and their use as biocides. Patent EP 249328, 1987. 

Interest in (5,5)-fused ring systems developed in separate, albeit closely related, directions. In the first, chemists continue their quest for new compounds having unique biological, chemical and physical properties. In the second, emphasis is on the classification of aromaticity based upon molecular conformity with Hiickel s rule. An increasing understanding of the fundamental chemistry of heterocyclic ring systems has led to considerable advances in this field, as evidenced by the growing list of applications as biocides and in industrial processes. 

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