1974/08/01 by Yoshinori Kidani, Kazuo Ohira, Hisashi Koike
Chemistry · #Analytical chemistry methods development #Inorganic and Organometallic Chemistry #Synthesis and Biological Evaluation
paper · pdf · doi:10.1246/bcsj.47.2040
crossref issued 1974/08/01 · crossref published 1974/08/01 · crossref published-print 1974/08/01 · openalex publication_date 1974/08/01 · crossref published-online 2006/03/27 · crossref created 2006/07/20 · crossref deposited 2024/01/18 · openalex created_date 2025/10/10 · crossref indexed 2026/07/30 · openalex updated_date 2026/07/30
Abstract Spectrophotometric measurements were carried out for the stability constants of the divalent metal chelates of 2-quinoxalinecarboxylic acid and copper, nickel, cobalt and zinc in a 5% aqueous ethanol solution. Successive stability constants, logK1, of the copper, nickel, cobalt and zinc chelates were 3.30, 2.87, 2.83 and 2.80, respectively. The metal complexes were difficult to dissolve in water. Copper and cadmium afforded both 1 : 1 and 2 : 1 complexes, while other divalent metals such as nickel, cobalt, manganese, zinc and lead resulted in the 2 : 1 complex formation. From the results of IR and Far-IR spectral analyses it was found that the carboxyl group and the ring nitrogen group appear simultaneously in the chelate formation. Copper complexes of 2-quinoxa-linecarboxylic acid 1- and 4-oxides, as well as its 1,4-dioxide were also studied.