Structural diversity of nucleotide coordination polymers of cytidine mono-, di-, and tri-phosphates and their selective recognition of tryptophan and tyrosine

Understanding the coordination geometry of nucleotide mono-, di-, and triphosphates is pivotal for unraveling the intricate relationships between molecular structure and biological function, particularly in metal-ligand interactions and their role in biomolecular recognition. This study investigates the structure of nucleotide-metal polymers and their selective interactions with amino acids, specifically tryptophan (Trp) and tyrosine (Tyr). We synthesized and comprehensively analyzed five coordination polymers of cytidine nucleotides: cytidine monophosphate (CMP), deoxycytidine monophosphate (dCMP), cytidine diphosphate (CDP), and cytidine triphosphate (CTP), which are {[Cu(CMP)(bpa)(H₂O)₃](CMP)·3H₂O}<i>n</i> (1), {[Cu₂(dCMP)(4,4'-bipy)₂(H₂O)₂]·4H₂O}<i>n</i> (2), {[Cu₂(CDP)₂(azpy)(H₂O)]·3H₂O}<i>n</i> (3), {[Cd₂(CDP)₂(bpa)₂(H₂O)₂]·8H₂O}<i>n</i> (4), and {[Cu(CTP)(2,2'-bipy)]·2H₂O}<i>n</i> (5), where (3), (4) and (5) mark the first report of CDP and CTP coordination complexes. Single-crystal X-ray diffraction unveiled the structure of the polymers to be one-dimensional (1, 5) or two-dimensional (2, 3, 4). Circular dichroism (CD) spectroscopy in both the solid and solution states elucidates the chirality-driven assembly in these nucleotide-metal polymers. The selective interactions of coordination polymers with tryptophan (Trp) and tyrosine (Tyr) were studied using spectroscopic titrations. Experimental and computational analyses reveal distinct interactions between all five coordination polymers and the amino acids, highlighting their biosensing potential. Binding affinity variations across the polymers offer insights into nucleotide-metal coordination chemistry and suggest applications in molecular recognition and functional materials.