High-performance thin-layer chromatographic mobility of porphyrins and their copper complexes on different adsorbents

Abstract

The R F values of twelve synthetic porphyrins including porphine and phenyl- and alkyl-substituted porphines, and also of their copper complexes, were obtained on thin-layer chromatographic plates coated with silica gel, cellulose, NH 2-bonded silica gel and octadecyl-bonded silica gel (ODS) with different developing solvents. On the first three plates, the mobilities ( R F values) of each porphyrin were always smaller than those of the corresponding copper complex, whereas the opposite occurred on the last plate. With an identical solvent, the mobilities of both a porphyrin and its copper complex increase in the following order of polar adsorbents: silica gel < NH 2-silica < cellulose. meso-Tetra(4-pyridyl)porphine was adsorbed so strongly on every polar adsorbent that it hardly migrated from the origin, whereas a large migration with the R F ≈ 0.9 occurred on an ODS plate specifically with N,N-dimethylformamide.