Hydrogen-bonded assemblies of two organically templated borates: syntheses and crystal structures of [(1,10-phen)(H3BO3)2] and [2-EtpyH][(B5O6(OH)4]

Abstract

Abstract Two new organically templated borates, [(1,10-phen)(H3BO3)2] (1) and [2-EtpyH][(B5O6(OH)4] (2), were synthesized under mild solvothermal conditions and characterized by single-crystal X-ray diffraction, FT-IR, elemental analyses and thermogravimetry. Complex 1 is a co-crystal component in which B(OH)3 molecules form crinkled tapes via hydrogen bonds, which in turn are packed in a two-dimensional framework with 1,10-phen molecules sandwiched between the framework of crinkled chains. The structure of complex 2 is composed of 2-ethylpyridinium cations [2-EtpyH]+ and pentaborate anions [B5O6(OH)4]– which are linked together with hydrogen bonds to form a three-dimensional supramolecular framework. The templating [2-EtpyH]+ cations are situated in the cavities arising from the supramolecular pentaborate framework and interact also with the inorganic framework through hydrogen bonds.