Synthesis, characterization, and DNA-binding and -photocleavage properties of water-soluble lanthanide porphyrinate complexes

摘要

A series of cationic lanthanide porphyrinate complexes of the general formula [(Por)Ln(H_2O)_3]~+ (Ln ~(3+)=Yb~(3+) and Er~(3+)) were synthesized in moderate yields through the interaction of meso-pyridyl-substituted porphyrin free bases (H_2Por) with [Ln{N(SiMe_3)_2}_3] ·x [LiCl(thf)_3], and the corresponding neutral derivatives [(Por)Ln(L_(OMe))] (L_(OMe)-= [(?·~5-C_5H_5)Co{P(=O)(OMe) _2}_3]~-) were also prepared from [(Por)Ln(H _2O)_3]~+ by the addition of the tripodal anion, L_(OMe)~-, an effective encapsulating agent for lanthanide ions. Furthermore, the water-soluble lanthanide(III) porphyrinate complexes-including [(cis-DMPyDPP)Yb(H_2O)_3]Cl_3 (cis-DMPyDPP=5,10-bis(N-methylpyridinium-4′-y1)-15,20-di(phenyl)porphyrin), [(trans-DMPyDPP)Yb(H_2O)_3]Cl_3 (trans-DMPyDPP=5,15-bis(N-methylpyridinium-4′-y1)-10,20-di(phenyl) porphyrin), [(TMPyP)Yb(L_(OMe))]I_4, and [(TMPyP)Er(L OMe)]I4 (TMPyP=tetrakis(N-methylpyridinium-4-y1)porphyrin) -were obtained by methylation of the corresponding complexes with methyl iodide and unambiguously characterized. The binding interactions and photocleavage activities of the water-soluble lanthanide(III) porphyrinate complexes towards DNA were investigated by UV-visible, fluorescence, and near-infrared luminescence spectroscopy, as well as circular dichroism and gel electrophoresis.