Abstract
2-Carboxy-1,10-phenanthroline has been prepared by brominating 2- methyl-phenanthroline and then hydrolysing in acidic solution the resultant 2-tribromomethyl derivative. The acid acts as a tridentate chelating agent and six-coordinate inner complexes of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), and zinc(II) as well as a complex of iron(III) are described. The formulation of the complexes as six-coordinate is supported by their magnetic and spectral properties. The temperature dependence of the magnetism of the iron(II) complex indicates that the complex is a simple paramagnetic.