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

Abstract

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 13C 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 LiO4 (tetrahedral) and LiO5 (distorted square pyramidal), in the same framework. © 2010 Elsevier B.V. All rights reserved.