The preparation of two distinct calix[4]pyrrole-modified silica gels is reported. These systems, designed to investigate the binding characteristics of calix[4]]pyrroles with anionic and neutral substrates, also provide a new solid support for the HPLC separation of nucleotides, oligonucleotides, N-protected amino acids and perfluorinated biphenyls. Binding affinities for the interaction of anions with calix[4]pyrrole amide derivatives are also reported; these were determined from H-1 NMR spectroscopic analyses carried out in CD2Cl2.