Chemistry Reference
In-Depth Information
studies performed by Fuentes-Cabrera
et al.
pointed out that neither planar nor
nonplanar models have electronic properties that correlate with M-DNA (M = Zn)
or could give an explanation for a measured conductivity for M-DNA in terms of
metal cation d-states.
74
The enhanced conductivity could be due to a signifi cant
decrease of the HOMO-LUMO gap of some forms of M-DNA as compared to that
of DNA, but more research is needed to understand whether further reduction
in the HOMO-LUMO gap takes place upon metal ion binding to base pairs.
Despite the above-mentioned diffi culties in the characterization of M-DNA,
potential use as molecular wires in nanocircuits makes M-DNA, or synthetic ana-
logues, promising materials for nanotechnological applications.
4.6 Conclusion
The aim of this chapter has been to provide an overview of the
supramolecular
aspects of metal-nucleobase chemistry. Much of the small molecule coordination
chemistry of DNA bases is well established through the efforts of numerous
groups. However, the organization of molecules into functional systems, with
specifi c tailor-made properties, remains a challenge. The hugely anticipated
development of molecular-based devices, along with the shift from top-down to
bottom-up assembly, still requires key contributions from a range of disciplines. It
is perhaps by combining the unique properties of metal ions, e.g. switchable oxida-
tion states, electronic and magnetic effects etc., with the diverse ligand-binding
modes of nucleobases, that those important breakthroughs may be made. The
bifunctionality of the building blocks of life, multiple metal-ion binding allied with
complementary hydrogen bonding, offers a powerful means by which to organize
molecular systems. From the breadth of complex types discussed herein, it is obvious
that metal ion-nucleobase interactions will continue to warrant research for many
years to come.
Acknowledgements
Financial support by the Ministerio Español de Educación y Ciencia, Comunidad
de Madrid (projects no. MAT2007 - 66476 - C02 - 02, MAT2005 - 03047, NAN2004 -
09183 - C10 - 06, CTQ2006 - 027185 - E, and S - 0505/MAT/0303) and European Com-
munity (FP6-029192) is gratefully acknowledged.
