Interaction of porphyrin and sapphyrin macrocycles with nucleobases and nucleosides - Spectroscopic, quantum chemical and chromatographic investigation

Novel oligopyrrole macrocycle-based sorbents were prepared via amide covale nt bonding of carboxylic acids of porphyrin and sapphyrin derivatives to 3- aminopropyl silica. Covalent attachment of Cu(II)-tetraphenylporphyrin form yl-derivative was performed by amine linkage. Prepared sorbents were charac terized by Raman spectroscopy and elemental analysis. Retention behavior of nucleobases and nucleosides was investigated by HPLC. UV-VIS and H-1 NMR t itrations were used to study the role of oligopyrrol macrocyclic receptors for selective recognition of adenine, cytosine, thymine and uracil and thei r nucleoside forms. The spectroscopic results were compared with quantum ch emical calculations at semiempirical level and with the data obtained by HP LC measurements. Obtained data suggest that an aromatic pi-pi stacking inte ractions govern the HPLC separation. A different behavior was found for pur ine and pyrimidine bases. An introduction of Cu(II) into porphyrin macrocyc le led to a dramatic increase of separation efficiency, probably due to an increase of interaction energy. (C) 2001 Elsevier Science B.V. All rights r eserved.