ABSTRACT
MOF-808, owing to the synergistic effect of its large surface area and surface charge matching, showed a diclofenac sodium (DCF) removal capacity as high as 630 mg g-1, and the ability to adsorb 436 mg g-1 DCF in two hours, outperforming many common Zr-MOFs under the same conditions. Importantly, a series of free-standing mixed-matrix membranes made by combining polyacrylonitrile with MOF-808 were fabricated and exhibited high efficiency of removing DCF from water via an easily accessible filtration method.
ABSTRACT
Polymorphs of ZnHPO3·2H2O with centrosymmetry (Cmcm) and noncentrosymmetry (C2) structures were prepared by modified solution evaporation and seed-crystal-induced secondary nucleation methods. In Cmcm-ZnHPO3·2H2O, the zinc atoms are only octahedrally coordinated, while in C2-ZnHPO3·2H2O, they feature both tetrahedral and octahedral coordination. As a result, Cmcm-ZnHPO3·2H2O features a 2D layered structure with lattice water molecules located in the interlayer space, while C2-ZnHPO3·2H2O features a 3D electroneutral framework of tfa topology connected by Zn(1)O4, Zn(2)O6, and HPO3 units. The UV-visible diffuse reflectance spectra associated with Tauc's analyses give a direct bandgap of 4.24 and 4.33 eV for Cmcm-ZnHPO3·2H2O and C2-ZnHPO3·2H2O, respectively. Moreover, C2-ZnHPO3·2H2O exhibits a weak second harmonic generation (SHG) response and a moderate birefringence for phase matching, indicating its potential as a nonlinear optical material. Detailed dipole moment calculation and analysis confirmed that the SHG response mainly derived from the HPO3 pseudo-tetrahedra.
ABSTRACT
Two new indium sulfate tellurites, namely, In2(SO4)(TeO3)(OH)2(H2O) and In3(SO4)(TeO3)2F3(H2O), were synthesized by hydrothermal method in a one-pot reaction. Their pure phase yields have been successfully optimized to 76% and 21%, respectively. In2(SO4)(TeO3)(OH)2(H2O) crystallized in centrosymmetric (CS) space group P21/n, while In3(SO4)(TeO3)2F3(H2O) formed a non-centrosymmetric (NCS) and chiral space group P212121. The CS compound features a 2D layered structure composed of 2D indium oxide layers decorated by sulfate tetrahedra and tellurite groups. The NCS compound displays a 3D network consisting of indium tellurite layers bridged by sulfate tetrahedra. Powder second harmonic generation measurements disclosed that In3(SO4)(TeO3)2F3(H2O) exhibits a weak frequency-doubling efficiency about 11% of the commercial KDP. Its powder laser damage threshold quantity was estimated to be 79.6 MW/cm2, which is about 36 times that of AGS. The two samples present wide optical band gaps of 4.86 and 4.10 eV, respectively, which were determined by Te, In, and O atoms based on density functional theory calculations.
ABSTRACT
Metal-organic frameworks (MOFs) have potentially useful applications and an intriguing variety of architectures and topologies. Two homochiral coordination polymers have been synthesized by the hydrothermal method, namely poly[(µ-N-benzyl-L-phenylalaninato-κ(4)O,O':O,N)(µ-formato-κ(2)O:O')zinc(II)], [Zn(C16H16NO2)(HCOO)]n, (1), and poly[(µ-N-benzyl-L-leucinato-κ(4)O,O':O,N)(µ-formato-κ(2)O:O')zinc(II)], [Zn(C13H18NO2)(HCOO)]n, (2), and studied by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) each have a two-dimensional layer structure, with the benzyl or isobutyl groups of the ligands directed towards the interlayer interface. Photoluminescence investigations show that both (1) and (2) display a strong emission in the blue region.
ABSTRACT
Two homochiral coordination polymers based on a chiral reduced Schiff base ligand, namely poly[(µ5-4-{[(NR,1S)-(1-carboxylato-2-phenylethyl)amino]methyl}benzoato)zinc(II)], [Zn(C17H15NO4)]n, (1), and poly[(µ5-4-{[(NR,1S)-(1-carboxylato-2-phenylethyl)amino]methyl}benzoato)cobalt(II)], [Co(C17H15NO4)]n, (2), have been obtained by hydrothermal methods and studied by single-crystal X-ray diffraction, elemental analyses, powder X-ray diffraction, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) are isostructural and crystallize in the P2(1)2(1)2(1) space group. Both display a three-dimensional network structure with a one-dimensional channel, with the benzyl group of the ligand directed towards the channel. An investigation of photoluminescence properties shows that compound (1) displays a strong emission in the purple region.
ABSTRACT
The title compound, [Cd(C(8)H(18)NO(8)P(2))(2)](n), synthesized by hydrothermal methods, exhibits a layered structure in which the Cd(II) ion, occupying a centre of symmetry, is coordinated by six O atoms from four phosphonate ligands. The crosslinkage of CdO(6) octahedra by bridging phosphonate ligands results in a cadmium(II) phosphonate layer. Within the layer, there exists a 16-membered ring incorporating four -Cd-O-P-O- linkages. The uncoordinated carboxyl group of the ligand is oriented so that it penetrates the adjacent layer, taking part in hydrogen bonding to two uncoordinated phosphonate O atoms to form a CO(2)H/HO(2)P motif.
ABSTRACT
In the title complex, [CoCl(2)(C(12)H(8)N(2))(2)]·C(3)H(7)NO, which has twofold rotation symmetry, the Co(II) cation is coordinated by two 1,10-phenanthroline (phen) mol-ecules and two chloride ligands in a distorted octa-hedral geometry. In the crystal structure, a cavity is created by six complex mol-ecules connected by C-Hâ¯π inter-actions and non-classical C-Hâ¯Cl hydrogen bonds. The cavities are occupied by the disordered dimethyl-formamide solvent mol-ecule. The C and N atoms of the C-N bond in the solvent mol-ecule also lie on a crystallographic twofold rotation axis; the remaining atoms of the solvent are statistically disordered (ratio 0.5:0.5) about this axis.
ABSTRACT
The title complex, [Mn(C(6)H(5)N(2)O(4))(2)(H(2)O)(2)], was obtained by hydro-thermal synthesis. The Mn(II) atom, which lies on an inversion centre, displays a slightly distorted octa-hedral geometry. In the crystal packing, complex mol-ecules are linked by inter-molecular O-Hâ¯O and N-Hâ¯O hydrogen bonds to form a three-dimensional supramolecular structure. The title complex is isostructural with the corresponding cadmium(II) complex [Nie, Wen, Wu, Liu & Liu (2007 â¶). Acta Cryst. E63, m753-m755].
ABSTRACT
The title compound, [Mn(2)(HO(3)PCH(2)CH(2)COO)(2)(C(8)H(8)N(2))(2)(H(2)O)(2)], was obtained by hydro-thermal synthesis. The manganese(II) ions are six-coordinate and are linked by two 2-carboxy-ethyl-phospho-nate ligands, forming a centrosymmetric dimer. The Mn ions adopts a distorted octahedral coordination geometry. The dimers are further linked by O-Hâ¯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance 4.2754â (4)â Å].
