DUGi

The influence of substituents and the environment on the NMR shielding constants of supramolecular complexes based on A-T and A-U base pairs

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@2072@@294498

In the present study, we have theoretically analyzed supramolecular complexes based on the Watson-Crick A-T and A-U base pairs using dispersion-corrected density functional theory (DFT). Hydrogen atoms H8 and/or H6 in the natural adenine and thymine/uracil bases were replaced, respectively, by substituents X8, Y6 = NH - , NH 2 , NH 3 + (N series), O - , OH, OH 2 + (O series), F, Cl or Br (halogen series). We examined the effect of the substituents on the hydrogen-bond lengths, strength and bonding mechanism, and the NMR shielding constants of the C2-adenine and C2-thymine/uracil atoms in the base pairs. The general belief in the literature that there is a direct connection between changes in the hydrogen-bond strength and the C2-adenine shielding constant is conclusively rejected by our computations

The following organizations are thanked for financial support: the Ministerio de Ciencia e Innovación (MICINN, PhD-scholarship BES-2012-052792), the Ministerio de Economía y Competitividad (MINECO, CTQ2014-59212-P and CTQ2015-70851-ERC), GenCat (2014SGR1202 and XRQTC network) and European Fund for Regional Development (FEDER, UNGI10-4E-801)

Royal Society of Chemistry (RSC)