In accordance with the present invention there is provided a new class of
sterically demanding metallo-intercalators. These compounds intercalate
between bases in a duplex polynucleotide, but only where the bases are
not fully complementary, for example, where there is a base-pair
mismatch. The compounds are sufficiently sterically demanding that
intercalation between bases in fully complementary duplexes does not
occur to a significant degree. These mismatch intercalators are useful
for detecting DNA and RNA defects, for diagnosing disorders characterized
by the presence or increase in DNA and/or RNA defects, and for treating
such disorders. Further, the compounds are capable of catalyzing
photolytic cleavage of nucleic acids at relatively long wavelengths, and
under normal sunlight.
