Abstract: Heavy metal complexes can be prepared from azo compounds that contain a heterocyclic diazo component containing a complex-forming group such as hydroxyl, carboxyl, alkoxy or amino, or containing a hetero nitrogen atom able to form a coordinate bond, exemplified by quinolinyl and benzthiazolyl. The coupling component is 5-halogeno-2,3-dihydroxypyridyl where halogen is preferably chloro or bromo. The dyestuffs are useful, inter alia, for dyeing natural and synthetic polyamides such as wool and nylon. The dyeings obtained are uniform, are resistant to acid and alkali, are fast to light and to rubbing and barely change their appearance in artificial light.

Abstract: Azo compounds of the formulaD-N=N-K (1)wherein D denotes the radical of an aromatic diazo component and K denotes the radical of a halogeno-2,3-dihydroxy-pyridine, as well as heavy metal complexes of azo compounds of the formula (1).

Abstract: Chromium complex dyes of the formula ##SPC1##Wherein one of the symbols X.sub.1, X.sub.2 and X.sub.3 is hydrogen and each of the others is hydrogen, a halogen atom, a nitro group, a methyl or a methoxy group, R is a phenyl radical which is optionally substituted by halogen, low molecular alkoxy, alkyl or nitro and Me.sup.+ is a cation are disclosed; said dyes being useful in dyeing synthetic and natural polyamides to produce dyeings which are level and have good fastness to light, washing, fulling, decatizing and carbonizing.

Abstract: A mixed metal complex compound that contains for every atom of a trivalent metal one molecule of an azo or azomethine compound which contains a complex-forming group in the ortho, ortho'-positions to the azo or azomethine bridge, and one molecule of an azo or azomethine compound acting as trifunctional ligand which contains a complex-forming group in the ortho-position to the azo or azomethine bridge and contains two non-ionisable co-ordination positions. These mixed metal complexes dye nitrogenous fibers such as wool in level shades which are stable to acids and alkalis and have good fastness to light, rubbing, perspiration and water.