G-Quadruplex DNA structures have attracted increasing
attention
due to their biological roles and potential as targets for the development
of new drugs. While most guanine-rich sequences in the genome have
the potential to form monomeric G-quadruplexes, certain sequences
have enough guanine-tracks to give rise to multimeric quadruplexes.
One of these sequences is the human telomere where tandem repeats
of TTAGGG can lead to the formation of two or more adjacent G-quadruplexes.
Herein we report on the modular synthesis via click chemistry of dimeric
metal-salphen complexes (with NiIIand PtII)
bridged by either polyether or peptide linkers. We show by circular
dichroism (CD) spectroscopy that they generally have higher selectivity
for dimeric vs monomeric G-quadruplexes. The emissive properties of
the PtII-salphen dimeric complexes have been used to study
their interactions with monomeric and dimeric G-quadruplexesin vitroas well as to study their cellular uptake and localization.