The Reaction between Mercury(II) and Organic Compounds. II. The Composition of a Mercury(II)- l -Histidine Complex in an Ethanol-Water Solution

The composition of the complex formed with l-histidine and mercury(II) in a solution has been investigated spectroscopically. The complex formation in an aqueous solution was not observed, but in an alcoholic solution (1 : 1), there appeared about 274 mμ an absorption maximum which can be attributed to the complex formation. By the spectroscopic measurements of this alcoholic solution containing two components in various proportions, it was shown that only one kind of complex with a 1 : 1 composition was formed in a 50% ethanol-water solution at pH 3.25–3.75 and at 20°C. Accordingly, the composition of the complex may be considered to be as follows: (Remark: Graphics omitted.)