Oxinate groups

When benzotellurophene dioxinate was refluxed in benzene with equimolar amounts of halogenated acetic acids, one oxinate group was exchanged for an acetate group3. 

Hydroxyquinoline is a chelating ligand (referred to as oxine) which forms insoluble complexes with a number of di- and trivalent metals. The oxinates of these metals contain 2 or 3 oxinate groups per metal ion. In the case of aluminium the complex has 3 chelating ligands. Complete precipitation takes place at pH values of 5-10. 

The ability of HRP to degrade the plant hormone indole-3-acetic acid (lAA) in the absence of hydrogen peroxide was noted as early as 1955 (136). Plant peroxidases are now known to be of major importance in the metabolism of lAA (137) (note that they are often referred to as indole acetic acid oxidases in the older literature). The mechanism of lAA oxidation by HRP C is complex and has been studied experimentally in great detail by several groups (23, 137). Reaction products include indole-3-methanol, indole-3-aldehyde, and 3-methylene oxin-dole, which is probably a nonenzymatic conversion product of indole-3-methylhydroperoxide. The most important developments in this area have been reviewed (23). 

Oximes and hydroxamic acids, together with hydroxylamines, can be generally considered as a class of compounds having a common functional group —NOH—. Additional functional features distinguish these three parent classes of compounds. Some confusion often occurs over a reagent generally called oxine . This is not an oxime (and certainly not a hydroxamic acid) but rather is S-hydroxyquinoline. ... 

Hydroxybenzothiazole (10) has the same chelating group as oxine (7) and forms insoluble complexes with Cu, Ni, and Zn, which are relatively more soluble, probably because the sulfur atom tends to form hydrogen bonds with the solvent. 

Complexes of pyridine-2-carboxylic acid (picolinic acid, picH) and its substituted derivatives commonly exhibit the N—O bidentate nature of this aromatic amino acid. From aqueous solutions chelates are obtained with the coordinated carboxylic group deprotonated, or neutral ligand forms may be isolated from non-aqueous media.26 Bis chelates are common in either case with bivalent metal ions. The tris chelates of trivalent cobalt27 and manganese28 have been structurally characterized recently. The latter is tetragonally distorted in a structure similar to Mnin(oxine)3. 

Monomeric monoorganoantimony(V)(8-hydroxyquinolino)(V) chlorides have been prepared by the reactions of monoorganoantimony(V) chlorides with oxine in absolute ethanol385. H NMR and UV spectral data of these compounds indicate an octahedral configuration around antimony atom. Out of the two possible geometric forms, the one with R group on equatorial position has been considered as the most plausible form ... 

The more modern style of Skraup synthesis is used to make 8-quinolinol or oxine . ortho-Amino-phenol has only one free position ortho to the amino group and is very nucleophilic, so acrolein can be used in weak acid with only a trace of strong acid. Iron(III) is the oxidant with a bit of boric acid for luck, and the yield is excellent. 

The precipitation of Mg as Mg(NH4)P04.6H20 by the addition of a little NH4C1 and excess Na2HP04 to the ammoniacal solution (Section III.35, reaction 5) is sometimes rather slow also traces of Group IV metals tend to interfere. For these reasons the oxine and magneson tests are preferred. 

Bur for hormones such as oestrone and testerone two carbon atoms need removing to make a cyclopentanone. This is accomplished using a Beckmann rearrangement. The oxine forms with the OH group trans to the more bulky... 

---