Indexed on: 31 May '19Published on: 30 Mar '19Published in: Journal of Physical Chemistry B
The design of organometallic complexes used as selective intercalators to bind and react at DNA mismatch sites has concentrated efforts the last years. In this context, lanthanides have received attention to be employed as active optical centers due to their spectroscopic properties. Despite there are several experimental data about synthesis and DNA binding of these compounds, theoretical analyses describing their interaction with DNA are scarce. To understand the binding to regular and mismatched DNA sequences, as well as, to determine the effect of the intercalation on the spectroscopic properties of the complexes, a complete theoretical study going from classical to relativistic quantum mechanics calculations has been performed on some lanthanide complexes with phenanthroline derivatives synthesized and characterized herein, viz. [Nd(NO3)3(H2O)(dppz-R)] with R=H, NO2-, CN- and their [Nd(NO3)3(H2O)(dpq)] analogue which was computationally modelled. The results were in correct agreement with the available experimental data showing that dppz complexes have higher binding affinities to DNA than dpq one and supporting the idea that these complexes are not selective to mismatch sites in the sampled time scale. Finally, the spectroscopic analysis evidences an intercalative binding mode and made possible the elucidation of the emission mechanism of these systems. This approach is proposed as a benchmark study to extend this methodology on similar systems and constitutes the first theoretical insight in the interaction between DNA and lanthanide complexes.