Novel H-bonded base pairs as potential repeat units for information-bearing macromolecular duplexes: A B3LYP/6-31G*search

A number of sets of nitrogenous bases (substituted pyrimidines, pyrazines and pyridines) are studied using the B3LYP/6-31G* strategy (with counterpoise correction) for their ability to associate among themselves and form stable well-defined hydrogen-bonded base pairs. This is to determine their suitability to furnish base pairs which may serve as potential repeat units for H-bonded macromolecular duplexes with the capacity to store and replicate information at the molecular level. Five sets of three to four six-membered nitrogenous bases each are taken here to study their potential for forming two H-bonded base pairs which qualify as mimics of the DNA base pairs. Out of the possibilities thus tested, only one set - comprised of pyrimidine base units - satisfies the prescribed criteria and may be put forward as a good candidate to yield repeat units for designing these synthetic information-bearing macromolecular duplexes. (c) 2007 Elsevier B.V. All rights reserved.