Synthesis and crystal structure compound Adeninium Bis(pyridine-2,6-dicarboxylate) Chromate(III) pyridine-2,6-dicarboxylic acid tetra hydrate

A new supramolecular compound of adeninium bis(pyridine-2,6-dicarboxylate) Chromate(III) pyridine-2,6-dicarboxylic acid tetrahydrate (AdH+)[Cr(pydc)2](H2pydc).4H2O (1) (where Ad and H2pydc are adenine and pyridine-2,6-dicarboxylic acid, respectively) was synthesized via proton transfer method and its structure was determined using single crystal X-ray diffraction technique. This compound crystallizes in the orthorhombic crystal system with Pbca space group and the unit cell parameters are a = 14.180(14), b = 13.036(12),
c = 33.98(3) Å and α = β = γ = 90˚. The final R value is 0.053 for 2523 independent reflections. The asymmetric unit of compound 1 contains anionic, cationic and neutral species. The anionic part is a complex of Cr(III) with two coordinated pyridine-2,6-dicarboxylate groups and the cationic part is a protonated adenine. The neutral part has one molecule of pyridine-2,6-dicarboxylic acid and four hydration water molecules. The Cr(III)  atom in compound 1 adopts a distorted octahedral coordination geometry. All six coordination sites have been occupied by two deprotonated pyridine-2,6-dicarboxylate ligands. Non-covalent and intermolecular interactions i.e. Hydrogen bonds and C = O…π interactions are responsible for the self-assembled and regular structure of 1.