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Azidinium‐Salze. 25. Mitteilung . Symmetrische Azopyridinon‐Farbsalze: Synthese, spektrophotometrische und acidobasische Eigenschaften, Metallkomplex‐Bildung und kinetische Untersuchung der Azo‐Kupplung
Author(s) -
Balli Heinz,
Chaquime Lucy,
Hellrung Bruno,
Misun Marian
Publication year - 1994
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19940770124
Subject(s) - chemistry , dimethylformamide , metal , polymer chemistry , complex formation , medicinal chemistry , photochemistry , inorganic chemistry , organic chemistry , solvent
Symmetrical Azopyridinone Dyes: Synthesis, Spectrophotometrical and Acidobasic Properties, Metal‐Complex Formation and Kinetical Investigation of the Azo‐Dye Formation The 13 substituted symmetrical azopyridinone dyes 2a–n were synthesized and their VIS spectra measured. The p K * a values of some dyes and of pyridinone coupling components were determined in MeOH/H 2 O 64:36. The metal‐complex formation of the dyes with Cd 2+ , Zn 2+ , Co 2+ , Ni 2+ , and Cu 2+ was investigated, and complex‐formation constants of the 1:1 complexes were determined in H 2 O for 2k ( Table 2 ) and in dimethylformamide/H 2 O 1:1 for some other azopyridinone dyes ( Table 3 ). The mechanism of the azo‐dye formation was investigated and found to be much more complicated than expected. A mechanism of the coupling reaction was developed ( see Scheme 4 ) and fitted by least‐squares calculations.