Characterization of the complex formation of 1,6-anhydro-β-maltose and potassium ions using NMR spectroscopy and single-crystal X-ray crystallography Original Research Article

The formation of a complex between 1,6-anhydro-β-maltose and potassium ions was characterized using 1H, 13C and 39K NMR spectroscopy and single-crystal X-ray crystallography. In the NMR study, the spin-lattice relaxation times (T1) of C1, C3, C5, C6, and C5′ significantly decreased in the presence of potassium ions, and 39K-T1 also decreased in the presence of 1,6-anhydro-β-maltose, indicating complex formation. In a crystal, both 8- and 9-coordination structures, corresponding to the distorted capped pentagonal bipyramidal structure and the capped hexagonal bipyramidal structure, respectively, were identified. A potassium ion was positioned in the center of each bipyramidal structure.