A Series of Aluminoborates Templated or Supported by Zinc-Amine Complexes

A series of open-framework aluminoborates (ABOs), namely, [Zn₂(en)₅][Al₂B₁₀O₂₀] (1), [Zn(en)(dien)][AlB₅O₁₀] (2), [Zn(en)₃][AlB₇O₁₂ (OH)₂] (3), [Zn(en)₂][AlB₅O₁₀] (4), K₇{AlO_0.5[BO₂(OH)]ZnB₁₂O₂₁(OH)₃]}·H₂O (5) (en=ethylenediamine, dien=diethylenetriamine) have been made under mild solvothermal conditions and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR and UV/Vis spectroscopy, thermogravimetric analysis, and nonlinear optical determination. They were classified as two types: Compounds 1-4 contain intersecting channels and exhibit various 4-connected nets built by AlO₄ tetrahedra and oxo boron clusters, zinc-amine complexes act as the templates (1-3) or directly bond to the walls of the ABO (4); compound 5 exhibits a double-layer structure made by nanosized [BO₂(OH)]ZnB₁₂O₂₁(OH)₃] ({BZn@B₁₂}) clusters with Al₂O₇ dimers, the channels are within the layer. The second harmonic generation (SHG) measurement shows that the SHG responses of 1-3 are about 2.5, 1.6, and 0.5 times that of KH₂PO₄. Compounds 1-2 are type I phase-matchable materials. UV/Vis spectroscopy indicates that compounds 1-5 are wide-band-gap semiconductors.