Copper 8-hydroxyquinoline — Oxine

Substance classes Properties — Effectiveness — Applications 11.5 Copper 8-hydroxyquinoline — Oxine copper... 

S-hydroxyquinoline, oxine, C9H7ON. Light brown needles, m.p. 15-16 C. Forms insoluble complexes with metals. The solubilities of the derivatives vary with pH, etc. and hence oxine is widely used in analysis. Used for estimating Mg, Al, Zn and many other metals. Many oxinates are extracted and the metal is estimated spectrophotometrically. Derivatives, e.g. 2-meIhyl tend to be specific, for, e.g.. Copper derivatives are used as fungicides. 

Copper quinolinolate (oxine copper) is the chelate of divalent copper and 8-hydroxyquinoline and shares most of its market with copper naphthenate, which is a complex copper salt of mixed naphthenic acids. The principal uses are in wood treatments and some military textiles, where the green color is not objectionable. Copper naphthenate has an odor but is cheaper than oxine. Both copper naphthenate and 2inc naphthenate have performed well in environment tests, with exposure to soil above-ground, as well as concrete (33). 

Hydroxyquinoline (oxine, 8-quinolinol) [148-24-3] M 145.2, m 71-73 , 75-76 , 76 , b 267 pKj 4.91, pK 9.81. Crystd from hot EtOH, acetone, pet ether (b 60-80 ) or water. Crude oxine can be purified by pptn of copper oxinate, followed by liberation of free oxine with H2S or by steam distn after acidification with H2SO4. Stored in the dark. Forms metal complexes. [Manske et al. Can J Research 27F 359 1949 Phillips Chem Rev 56 271 1956.]... 

Oxido-p-menthane. See Eucalyptol 8a-12-Oxi do-13,14,15,16-tetranorlabdane. See Tetramethyidodecahydronaphthofuran Oxime. See Thallium (I) carbonate Oxime copper. See Copper 8-quinolinolate 2-Oximiminobutane. See Methyl ethyl ketoxime 1-Oxindene. SeeCumarohe Oxine. See,8-Hydroxyquinoline Oxine benzoate. See 8-Hydroxyquinoline benzoate... 

The prerequisite for the toxic effect of heavy metals is penetration of the cell wall. For this, certain carriers are needed to transport the heavy metals through lipophilic centres in the cell membrane. Oxines, 2-mercapto-pyridine-N-oxides (III. 11) and dialkyl-dithiocarbamates (III.9) are examples of compounds capable of complexing heavy metal ions such as Cu ions and transporting them into the microbe cell. The carriers named are also toxic, as such, to micro-organisms. But, as a copper carrier, copper-8-hydroxyquinoline is about 100 times more effective than 8-hydroxyquinoline (oxine III. 11.4). Once heavy metal ions have overcome the cell wall with the aid of the carrier molecules, they may compete with magnesium, calcium and potassium ions for receptor sites, inhibit enzymes and cause non-specific precipitation of proteins. 

Discussion. Various metals (e.g. aluminium, iron, copper, zinc, cadmium, nickel, cobalt, manganese, and magnesium) under specified conditions of pH yield well-defined crystalline precipitates with 8-hydroxyquinoline. These precipitates have the general formula M(C9H6ON) , where n is the charge on the metal M ion [see, however, Section 11.11(c)]. Upon treatment of the oxinates with dilute hydrochloric acid, the oxine is liberated. One molecule of oxine reacts with two molecules of bromine to give 5,7-dibromo-8-hydroxyquinoline ... 

SYNS BIOQUIN BIOQUIN 1 BIS(8-QUINOUNATO)COPPER BIS(8-QUINOLINOL-ATO)COPPER BIS(8-QUINOLINOLATO-NLo )-COPPER CELLU-QUIN COPPER-8 COPPER HYDROXYQUINOLATE COPPER-8-HYDROXY-QUINOLATE COPPER-8-HYDROXYQUINOLINATE COPPER-8-HYDROXYQUINOLINE COPPER OXINATE COPPER (2-I-) OXINATE COPPER OXINE... 

HYDROXYQUINOLINE COPPER COMPLEX MILMER OXIME COPPER OXINE COPPER OXINE CUIVRE OXYQUINOUNOLEATE de CUA RE (FRENCH) QUINONDO... 

Powell (1946) and Mason (1948) found that the 2 1 complex of 8-hydroxyquinoline with copper, oxine-copper, has a stronger fungicidal action than 8-hydroxyquinoline. Albert et al. (1953) attributed this to the fact that the organic part of the compound makes copper lipoid-soluble and thus accelerates its penetration into the cell. Inside the cell the 2 1 complex dissociates into a 1 1 complex and free 8-hydroxyquinoline. The active toxic agent is the ionised 1 1 complex of nonlipoid properties, which reacts with the enzymes in the fungus and blocks their function. This theory is also supported by the research work of McNew and Gershon (1969). 

Oxine-copper, bis(8-quinoIinoiato)copper (29) is an olive-green crystalline substance, insoluble in water, alcohols and most of the organic solvents. Oxine-copper, can be prepared from the aqueous solution of a copper(II) salt by precipitation with 8-hydroxyquinoline. 

Synonyms Bis (8-o> quinoline) copper Bis (8-quinolinato) copper Bis (quinolin-8-olato) copper Copper-8 Copper hydroxy quinolate Cop-per-8-hydroxyquinolinate Cop r-8-hydroxyquinoline Cc per oxinate Copper oxyquinolate Copper oxyquinoline Copper quinolate Cop-per-8-quinolate Cupric-8-hydroxyquinolate 8-Hydroxyquinoline copper complex Qxime copper Qxine copper Classification Organic copper compd. 

Hydroxyquinoline benzoate (salt). See 8-Hydroxyquinoline benzoate 8-Hydroxyquinoline copper complex. See Copper 8-quinolinolate 8-Hydroxyquinoline sulfate CAS 134-31-6 EINECS/ELINCS 205-137-1 Synonyms Bis (8-hydroxyquinolinium) sulfate Chinosol Oxine sulfate Oxyquinoline sulfate (INCI) 8-Quinolinol hydrogen sulfate (2 1) 8-Quinolinol sulfate 8-Quinolinol sulfate (2 1) (salt)... 

Oxine copper. See Copper 8-quinolinolate Oxine sulfate. See 8-Hydroxyquinoline sulfate p-Oxinozon. See 4-(2-Naphthylamino) phenol Oxirane. See Ethylene oxide Oxiranecarboxylic acid, 3-methyl-3-phenyl-, ethyl ester. See Ethyl methylphenylglycidate Oxirane, [1,1-dimethylethoxy) methyl]-. Seet-Butyl glycidyl ether... 

The antimicrobial activity described here is only valid for 8-hydroxyquinoline and not for the seven other possible hydroxyquinolines which are widely inactive and do not, as does 8-hydroxyquinoline, chelate metal cations, e.g. copper, iron and zinc. Contrary to Oxine the corresponding chelation complexes, e.g. copper 8-hydroxyquinoline (Section 11.5) possess considerable lipid solubility enabling the complex to pass through the cell membrane and then to dissociate into the toxic 8-hydroxyquinoline. However, according to the findings of Block (1983)... 

As is demonstrated in Table 99, Oxine is a broad spectrum microbicide, although it is much more toxic for Gram-positive bacteria than for Gram-negative bacteria. But unfavourable solubility properties and coloration risks have prevented Oxine from becoming an important microbicide for material protection. More popular are the chelate complexes, above all copper 8-hydroxyquinoline (Section 11.5). 

In view of its constitution, Alizarin Blue (I) might be expected to display the characteristics of alizarin (page 96) and 8-hydroxyquinoline (page 335). This is not the case, as shown by the facts that it is neither soluble in alkali as is alizarin nor in dilute acids as is oxine. Probably Alizarin Blue is a chelate compound as represented in (la). Solutions can be prepared in dioxane, pyridine, acetic anhydride, concentrated sulfuric acid. These solutions react with strongly acid solutions of copper salts to produce a com-flower-blue crystalline precipitate, whose constitution as an inner complex compound is shown in (II). 

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