Studies on the structure and chirality of A-motif in adenosine monophosphate nucleotide metal coordination complexes

Abstract

Nucleotide constructs B-DNA and non-B DNA. Non-B DNA leads to the genetic instability, genetic diseases and rearrangement of bases. The adenine–adenine base pair mismatch (A-motif) is considered to be the origin of some types of diseases unknown to humanity. One of the stumbling blocks in the study of the mismatched base pairs is short of the structural evidences or details, which arises from the difficulties of crystallizing the nucleotide compounds. Towards this aim, we have designed and constructed three 1D coordination polymers, namely {[Cd(bpe)(HdAMP)₂(H₂O)₂]·(bpe)·(CH₃OH)·4H₂O}_n (1), {[Mn(bpe)(HdAMP)₂(H₂O)₂]·(bpe)·8H₂O}_n (2) and {[Cd(AMP)(bpe)(H₂O)₃]·7H₂O}_n (3). All of them have been characterized structurally via single crystal X-ray diffraction. The complexes 1 and 2 have A-motif structures, while the complex 3 does not have the A-motif structure. The intermolecular recognition and interactions for the construction of A-motif have been described according to the comprehensive analysis of single crystal structures. It is a rare report on A-motif single crystals in the field of nucleotide coordination polymers. Moreover, the chiralities of the three complexes have been investigated by the combination of single crystal structure and solid-state chiral dichroism (CD) spectroscopy. In this study, for the first time, the novel supramolecular chirality of extending axial chirality (EAC) has been confirmed by complex 3 as an excellent example, and complexes 1 and 2 as a counterexample.