Synthesis of a rod-based porous coordination polymer from a nucleotide as a sequential chiral inductor

Abstract

We report the two-step synthesis of a novel chiral rod-based porous coordination polymer (PCP). The chemical approach consists of the use of a previously prepared bis(ethylenediamine) copper monomer [Cu(en)]2(NO3)2 [where en = ethylenediamine] reacting with the cytidine 5′-monophosphate (CMP) nucleotide. The bis(ethylenediamine) copper compound—stabilized by axial coordination of nitrate counter-anions—reacts in the presence of sodium salt of CMP to yield right-handed copper(II) chains of P helicity with formula [Cu2(en)2(CMP)2]·5H2O (1). The axial coordination of the CMP2- ligands through the N3 and O2 sites (free nitrogen and carbonyl groups) of the cytosine nucleobase and oxygen atoms of phosphate moieties, ensure stabilization of the neutral chiral polymer. The supramolecular organization involves strong hydrogen bonding interactions to build supramolecular chains of the same helicity. The resulting PCP constitutes one of the few examples of CMP compounds exhibiting coordination involving both nucleobase and phosphate moieties, where a highly stable metal complex is used as precursor for the rational construction of rod-based hydrogen metal-organic frameworks (HMOFs). Furthermore, it shows the intrinsic capability of biomolecules to act as chiral transfer systems.