Search

Four new phosphites/phosphates, namely Al[P2O3(OH)3](H2O), Al[(HPO3)(OH)(H2O)], Ca[HPO3] and Al3P6O19.5, were designed and synthesized by low temperature flux methods. They crystallized in P63mc, P1¯, P43212, and P63/m space groups, respectively. The basic units of Al[P2O3(OH)3](H2O), Al[(HPO3)(OH)(H2O)] and Ca[HPO3] are composed of [PO3]3− or/and [AlO6]9− groups, whereas the structure of Al3P6O19.5 is built from [PO4]3− tetrahedra and [AlO6]9− octahedra. The structure of Al[P2O3(OH)3](H2O) features a two-dimensional (2D) layered motif of Al[P2O3(OH)3]. Meanwhile, Al[(HPO3)(OH)(H2O)] has high porosity and relatively large channels, and has an excellent molecular sieve structure. Both Al[P2O3(OH)3](H2O) and Al[(HPO3)(OH)(H2O)] display deep ultraviolet (UV) cut-off edges of ∼195 nm and ∼193 nm. The three-dimensional (3D) structure of Al3P6O19.5 is formed by [Al2O9] dimers connected with six PO4 tetrahedra, and one PO4 tetrahedron linked three [Al2O9] dimers alternately. Importantly, Ca[HPO3] shows a moderate second harmonic generation (SHG) effect with a short UV cut-off edge of ∼192 nm in the deep-UV region. The syntheses and topological structures of Al[P2O3(OH)3](H2O), Al[(HPO3)(OH)(H2O)], Ca[HPO3] and Al3P6O19.5, together with some related properties, such as nonlinear optical (NLO) properties, elemental analysis, thermal stability, infrared spectroscopy, Raman spectroscopy and UV-vis diffuse reflectance spectroscopy, are also discussed. [ABSTRACT FROM AUTHOR]

Two novel alkali metal aluminophosphates, namely, Li3[Al(PO4)2(H2O)1.5] and Na[AlP2O7], were synthesized through low-temperature flux methods. They crystallized in the P4 and C2/c space groups, respectively. Both structures of Li3[Al(PO4)2(H2O)1.5] and Na[AlP2O7] were built up by AlO6 octahedra and PO4 tetrahedra. The structure of Li3[Al(PO4)2(H2O)1.5] was composed of novel two-dimensional (2D) aluminophosphate layers, which contained two types of eight-membered rings (8-MRs) along the c-axis. The structure of Na[AlP2O7] featured a unique 3D anionic framework composed of corner-sharing isolated AlO6 octahedra and PO4 tetrahedra. Three intersecting tunnels along the [001], [110], and [101] directions could be observed. Importantly, the material Li3[Al(PO4)2(H2O)1.5] crystallized in the polar space group P4, showing a moderate second-harmonic generation (SHG) effect. Moreover, Na[AlP2O7] exhibited a wide transparency range with a short ultraviolet (UV) cut-off edge (∼190 nm), which indicated its potential application in the deep-UV region. Herein, the syntheses and topological structures of Li3[Al(PO4)2(H2O)1.5] and Na[AlP2O7], as well as elemental analysis, thermal stability, infrared spectroscopy, UV-vis diffuse reflectance, structural properties, and nonlinear optical (NLO) properties are also discussed. [ABSTRACT FROM AUTHOR]

Crystals of three novel highly porous aluminophosphates, namely, α-NaAlPO4(OH) (1), β-NaAlPO4(OH) (2) and Al3.5P5.5O19 (3), were synthesized through mild hydrothermal methods. Interestingly, among these three porous aluminophosphates, 1 is polar, whereas the other compounds are nonpolar and centrosymmetric. The 3D framework structure of 1 is built from AlO6 octahedra and isolated PO4 tetrahedra. 1D Al-chains are linked by PO4 tetrahedra via sharing corners, forming the 3D framework, and 1D 8-membered ring (MR) tunnels were observed along the c-axis. Importantly, the material of 1 exhibits a moderate second harmonic generation (SHG) effect. 2 features a unique 3D anionic framework composed of corner-sharing [Al2O11] dimers and isolated PO4 tetrahedra. Three intersecting tunnels along the axes can be observed; the small tunnels along the c-axis are based on 4-MRs, whereas the two 6-MRs are along the a- and b-axes. The structure of 3 displays a unique 3D framework based upon face-sharing [Al2O9] dimers and isolated PO4 tetrahedra. The small tunnels along the a- and b-axes are based upon 4-MRs, whereas the 1D larger tunnels are based on 12-MRs along the c-axis. Here, the syntheses and topological structures of α-NaAlPO4(OH) (1), β-NaAlPO4(OH) (2) and Al3.5P5.5O19 (3) as well as their elemental analysis, thermal stability, infrared spectroscopy, UV-vis diffuse reflectance and nonlinear optical (NLO) properties are also reported. [ABSTRACT FROM AUTHOR]