Complexes of iron (III) with derivatives of 8-quinolinol

The organic ligands 5- and 7- methyl-8-hydroxyquinoline have been synthesised and shown to form green, water soluble, 1:1 complexes with iron(III) and thus to possess the same composition as the complexes with 8-hydroxyquinoline and 2-methyl-8-hydroxyquinoline previously reported. Thermodynamic formation constants for the 1:1 complexes of 2-, 5- ,and 7-methyl-8-hydroxyquinoline with iron(III) have been determined -1 3 spectrophotometrically as 5.5. x 10¹⠴, 2.9 X 10¹⠵ and 3.6 x 10¹⠵ mole-¹ dm³ respectively at 25.0°C and I = 0.1M. When compared with the value 8.5 x lO¹⠴ for 8-hydroxyquinoline itself the results support the theory that methyl substitution affects the stability of these complexes by increasing the basicity of the nitrogen atom. The lesser stability of the 2-methyl complex, however, indicates an opposing steric effect of a bulky substituent in the 2-position.

Grantor dc:publisher.institution

Department of Chemistry

Year dc:date.issued

1981

Author dc:creator

• Golden, Corinne Ellen

Advisor dc:contributor.advisor

• Irving, H M N H

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/14967

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/14967