Studies in Lanthanide Ions Complexes with Some Substituted Sulphonic Acids

Department of Chemistry, Government Vidarbha Mahavidyalaya, Amravati-444 604

Manuscript received 17 September 1983, revised 1 August 1984, accepted  September 1984

The interaction of lanthanide ions (Ca^III, Ce^III ,Pr^III, Nd , Sm^III and Gd^Ill) with some substituted sulpbonic acids such as (i) 1,2-dihydroxybenzene-3,5-disulphonic acid (1,2 DHB-3, 5DSA), (ii) 6,7-dihydroxynaphthalene-2-sulphonic acid (6,7- DHN-2SA), (iii) 8-amino-1-naphthol-5,7-disulphonic acid(8A-1N-5,7-DSA), (iv) 8-amino1-naphthol-3,6-disulphonic acid (8A-1N-3,6-DSA), ( v) 8-amino-1-naphthol-3,5-disulphonic acid (8A-1N-3,5-DSA), (vi) 8-amino-1-naphthol-5-sulphonic acid (8A-1N-5SA), (vii) 7-amino-1-naphthol-3-sulphonic acid (7-A-1N-3SA), (viii) 2-aminobenzenesulphonic acid (2A-BSA), and (ix) 2-amino-4-methyl-5-chlorobenzenesulphonic acid (2A-4M-5CI-BSA) have been investigated at 30° and \(\mu\) = 0.1 M (NaCIO₄ ) by Calvio-Bjerrum technique La^III, Ce^III , Pr^III and Gd^III form 1:1 and 1:2 complexes but Nd^III and Sm^III form only 1 : 1 complex with all the sulphonic acids. The validity of log K= apk+b relation is examined for these complexes.