Coordinate compounds of trivalent lanthanides with 7-Phenylazo-8-Hydroxy-quinoline-5-Sulphonic acid and its halo derivatives

ABSTRACT

Trivalent Pr, Nd, Sm, Gd, Ho, Er, Yb and Y form MLn [n= 1-3] complexes in solution with 7-phenylazo-[I], 7[p-chlorophenylazo]-[II], 7 [p- bromophenylazo]-[III] and 7 [p-iodophenylazo]-8-hydroxyquinoline-5- sulphonic acid [IV]. The stability constants of the complexes were determined potentiometrically and correlated to the ionic potential, atomic number, ionization potential and electronegativity of the central metal ion. Solid complexes of [I] with the lanthanide ions have been prepared and their structure is studied by elemental and thermogravimetric analyses, IR spectroscopy and conductance measurements