PH Controlled the Supramolecular Assemblies of Two  Guanosine Monophosphate Cadmium Metal Coordination Complexes: Structure and Chirality

Abstract

In biological systems Chirality is important property from small molecules to macromolecules. The construction of homochiral coordination supramolecules in crystal and helical delivers the connection of molecular and macromolecular chirality. Complexity and properties in the presence of cadmium ion and bpe auxiliary ligand for bio-molecular guanosine-5- monophosphate disodium salt (GMP) was studied. The two Complexes 1 and 2 have been investigated the impact of auxiliary ligand bpe, hydroxy group on the sugar motif and pH for coordination of GMP ligands. The interaction of mixed ligands for growth and advancement of chiral complexes was controlled by the alteration of pH values for coordination of guanosine-5-monophosphate nucleotide with cadmium Cd (II) metal. The chirality of complexes 1 and 2 was studied with solid circular dichroism (CD) spectroscopy, including supramolecular chirality and extended auxiliary ligand (EAC) combining with the crystal structure analysis. The various hydrogen bonding and auxiliary ligand are the special means of transporting chirality from isolated molecules to dynamic supramolecular three-dimensional designs of GMP nucleotide crystals. The research results will be benefit to the controlling supramolecular assembly with well-defined structure and properties.

Solidarity of the Coordination Helix and Water Helix in the Nucleotide Coordination Polymer

“…It offers a successful example to describe the impact of pH on the coordination assembly of nucleotide− metal coordination complexes further. 34 Although no perfect single-strand water helix exists in complex-3, a pseudowater helix was observed.…”

“…For complex 3 , a different pH value (5.4) has been applied in the same synthesis components relative to complex 2 (6.4). It offers a successful example to describe the impact of pH on the coordination assembly of nucleotide–metal coordination complexes further . Although no perfect single-strand water helix exists in complex- 3 , a pseudowater helix was observed.…”

“…Due to the sensitivity of dTMP to pH value, the binding mode of the nucleotide and the stereospace undergo significant changes. Consequently, there is an adjustment in the intensity of supramolecular forces, resulting in the production of a 1D coordination polymer instead of the 2D structure synthesized in complex 2 . The crystal structure of complex 3 is a 1D homochiral coordination polymer with chiral space group P 2 1 and the flack parameter of 0.02(2) (Table S1).…”

“…Consequently, there is an adjustment in the intensity of supramolecular forces, resulting in the production of a 1D coordination polymer instead of the 2D structure synthesized in complex 2. 34 The crystal structure of complex 3 is a 1D homochiral coordination polymer with chiral space group P2 1 and the flack parameter of 0.02(2) (Table S1). The coordination spheres of Co 2+ ion show a distorted octahedral geometry including two N atoms of 4,4′-bipy at the axial position and three oxygen atoms of S6 and Figure S10c).…”