Anion Coordination of Bis‐bisurea Ligands: Aggregation of Dihydrogen Phosphate Anion into Oligomers and Infinite Chains

Abstract

AbstractA series of alkanediyl‐spaced bis‐bisurea ligands (L2–L4) were synthesized and their anion coordination behavior studied. These ligands form interesting complexes with polymeric and oligomeric dihydrogen phosphate aggregates in the solid state. The ligands L2 and L3 coordinate with H2PO4– anions to form a unique molecular “necklace” with an infinite (H2PO4–)n chain and surrounding ligand molecules. Meanwhile, two different dihydrogen phosphate‐water oligomers, (H2PO4)6·(H2O)4 and (H2PO4)4·(H2O)2, were observed in the complexes with the ligands L3 and L4. In addition, solution anion binding properties of the ligands were studied by 1H NMR and UV/Vis spectroscopy.