Binding of meso-tetrakis(N-methylpyridinium-4-yl)porphyrin to AT oligomers: effect of chain length and the location of the porphyrin stacking.

Circular dichroism (CD) spectra of meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) that are associated with various duplex and triplex AT oligomers were investigated in this study. A strong positive CD was apparent for both the TMPyP complexed with duplex d[(A-T)(12)](2), d(A)(12).d(T)(12) and triplex d(A)(12).