Boric acid complexes with organic biomolecules: Mono-chelate complexes with salicylic and glucuronic acids

摘要

Two mono-chelate borate complexes, lithium mono-salicylatoborate and sodium mono-glucuronatoborate, are reported for the first time. The complexes were isolated from aqueous solutions and characterized by FTIR (Fourier Transform Infrared) and ~(13)C MAS (Magic Angle Spinning) NMR techniques. Thermal stabilities of the complexes were examined by recording their TGA (Thermogravimetric Analysis) curves. Lithium mono-salicylatoborate, Li[B(Sal)(OH)_2], was isolated in crystal form and presented as a novel hybrid metal-organic framework possessing zeolitic structure. X-ray analysis revealed an original crystal structure constructed with solvate-free lithium ions adopting two different types of coordination polyhedra, corner-sharing LiO_4 (tetrahedral) and LiO_5 (distorted square pyramidal), in the same framework.