Two Cu-complex directed aluminoborates: from 2D layers to 3D frameworks

Abstract

With transition metal complexes as the structure-directing agents, two novel aluminoborates with a 2D layer [Cu(enMe)₂]₃{Al₂[B₅O₈(OH)₂]₄}·H₂O (1, enMe = 1,2-diaminopropane) and a 3D open-framework [Cu(en)₂][Al–B₅O₁₀] (2, en = ethylenediamine) have been solvothermally prepared and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, UV/Vis spectroscopy, powder and single-crystal X-ray diffraction. 1 is a 2D {Al[B₅O₈(OH)₂]₂}³⁻ layer constructed by the alternate linkages of AlO₄ groups and B₅O₈(OH)₂ clusters. The 2D layer contains 16-member rings (MRs), showing a unique sql net topology. In 2, the AlO₄ groups and B₅O₁₀ clusters alternately link together to form a 3D framework, in which the stacking of building layers is different. The copper centres are chelated by two amine ligands to form a square planar, which have weak axial interactions with the aluminoborate frameworks.