Hydrothermal Synthesis, Crystal Structures, and Enantioselective Adsorption Property of Bis(L-histidinato)nickel(II) Monohydrate

摘要

Despite the numerous researches in metal-organic frameworks (MOFs), there are only few reports on biologically important amino acids, histidine in particular, on its use as bridging ligand in the construction of open-framework architectures. In this work, hydrothermal synthesis was used to prepare a compound based on Ni~(2+) and histidine. The coordination assembly of imidazole side chain of histidine with divalent nickel ions in aqueous condition yielded purple prismatic solids. Single crystal X-ray diffraction (XRD) analysis of the product revealed structure for Ni(C_6H_8N_3O_2)2 ? H_2O that has a monoclinic (C2) structure with lattice parameters, a= 29.41, b= 8.27, c= 6.31 A, β= 90.01° .Circular dichroism - optical rotatory dispersion (CD-ORD), Powder X-ray diffraction (PXRD) and Fourier transform - infrared spectroscopy (FT-IR) analyses are conducted to further characterize the crystals. Enantioselective adsorption analysis using racemic mixture of 2-butanol confirmed bis(L-histidinato)nickel(II) monohydrate MOF crystal's enantioselective property preferentially favoring the adsorption of (S)-2-butanol isomer.