Copper hydrazone complexes

Synthesis of the copper complex31 [167780-70-3] (H, Na salt) involves coupling of a diazonium compound with a hydrazone [54] 2-(3-amino-4-hydroxyphe-nylsulfonamido)chlorobenzene is dissolved in hot water, to which dilute NaOH solution is then added. After addition of sodium nitrite, the solution is cooled to -5 °C and then added to a well-stirred mixture of HC1, water, and ice. The diazonium salt suspension is neutralized with NaHC03 and combined with the weakly acidic solution of the hydrazone formed with 2-hydrazino-5-sulfobenzoic acid and benzaldehyde in water. The reaction mixture is kept at 0-10 °C, and at pH 10-12 by dropwise addition of diluted NaOH. When the coupling is complete, the pH of the formazan solution is reduced to 8 with HC1, a dilute aqueous solution of copper tetraaminosulfate is added and the solution is stirred for several hours. The copper complex 31 is precipitated at 85-90 °C with NaCl, then filtered and dried. The resulting powder colors wool in clear, fast blue tones. 

Copper ions required for tumour angiogenesis may be chelated in two tridentate, hydrazone-copper complexes, pyridine-2-carboxaldehyde-2 -pyridylhydrazonato-Cu(II) and salicylaldehydeben-zoyl-hydrazonato-Cu(II), which inhibited the growth of an implanted methylcholanthrene-induced fibrosarcoma (MCA 1511) in Balb/C mice (PiCKART et al. 1983). 

No isomers were detected in the copper and nickel complexes of the strongly polarized o,o -dihydroxyazobenzene (89), the l-(2-hydroxyphenylazo)-2-naphthols (90), or the 1-phenyl-3-methyl-4-(2-hydroxyphenylazo)-5-pyrazolones (91). These compounds exist predominantly in the quinone hydrazone (92 and 93) and ketone hydrazone (94) forms, respectively (Section... 

Copper and nickel Chromium and cobalt N -Np Na-Np Meridional/facial coordination Azo/hydrazone tautomerism Non-planarity due to azo/hydrazone tautomerism Formation of two copper and two nickel complexes by unsymmetrical o.o -dihydroxyazobenzenes78 Detection of isomeric 2 1 chromium complexes 79 proton magnetic resonance80 Isolation of isomeric 2 1 chromium and cobalt complexes 86 87 limited X-ray crystallographic89 90 Proton magnetic resonance80 Detection of five isomeric 2 1 chromium complexes of symmetrical o.o -dihydroxydiarylazo compounds... 

Metal-Complex (Formazan) Dyes. The hydrazone from 2-carboxyphenylhydra-zine-4-sulfonic acid and benzaldehyde is suspended in water and then dissolved by adding aqueous sodium hydroxide to obtain pH 6.5 -7.0. This solution is added to the aqueous diazonium salt solution obtained from a typical aqueous diazotiza-tion of 4-(2-sulfooxyethylsulfonyl)-2-aminophenyl-6-sulfonic acid. The mixture is then dripped into an aqueous solution of copper sulfate, while the pH is maintained with soda at 5.5 - 6.5. After complete coupling the pH is adjusted to 1 with concentrated hydrochloric acid. The strongly acidic solution is then neutralized with alkali to pH 5.5. The copper - formazan complex is salted out along with sodium chloride, filtered, washed with dilute aqueous sodium chloride solution, and dried. A dark powder results which gives a dark blue solution in water. It consists of an electrolyte-containing powdered sodium salt of the acid 25 ... 

The hydrazones and osazones rarely have sharp melting points, and disparities in reported values are often encountered. Moreover, optical rotations are frequently difficult to determine because of slow, complex mutarotations. Confirmation of the identity through a comparison of X-ray patterns or through other derivatives is desirable. The osotriazoles (Chapter VIII) prepared from the osazones by the reaction of copper sulfate generally have properties quite suitable for qualitative analyses. Isolation of the more-soluble osotriazoles is facilitated by adsorption on and elution from activated carbon (29a),... 

To resolve this reactivity problem, we explored the possibility of employing a Lewis acid to activate the iV-acyl hydrazone by lowering its LUMO energy (Scheme 22) [145-147]. If successful, such an achievement would expand the possibilities for the development of new NHC reactions. The most important challenge to this idea is the known ability of carbenes to act as ligands and form stable complexes, particularly with late transition metals such as palladium and copper [148-151]. We hypothesized that early metals would react reversibly with NHCs, allowing for the development of a cooperative catalytic system. After... 

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