scholarly journals Forming a three-dimensional porous organic network via solid-state explosion of organic single crystals

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Seo-Yoon Bae ◽  
Dongwook Kim ◽  
Dongbin Shin ◽  
Javeed Mahmood ◽  
In-Yup Jeon ◽  
...  
1997 ◽  
Vol 52 (8) ◽  
pp. 989-993 ◽  
Author(s):  
B Mertens ◽  
Hk Müller-Buschbaum

Single crystals of Ba2,5Cd11(VO4)9 have been prepared by solid state reactions. The new compound crystallizes with orthorhombic symmetry, space group D142h-Pbcn, a = 20.842(6), b = 13.471(3), c = 11.838(9) Å, Z = 4. The crystal structure is characterized and dominated by CdO6 octahedra and unusual square pyramids of O2- around Cd2+ forming a three-dimensional [Cd11O36] network. The interstices are occupied by V5+ and Ba2+ ions. This results in VO4 tetrahedra and irregular BaO10 polyhedra isolated from each other. Occupation of the barium positions is deficient in agreement with the valence state V5+ and calculations of the coulomb terms of lattice energy.


2016 ◽  
Vol 72 (9) ◽  
pp. 1260-1262 ◽  
Author(s):  
Jamal Khmiyas ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

Single crystals of the title compound, CaZn2Fe(PO4)3, were synthesized by conventional solid-state reaction. In the asymmetric unit, all atoms are located in fully occupied general positions of theP21/cspace group. The zinc atoms are located on two crystallographically independent sites with tetrahedral and distorted triangular-based bipyramidal geometries. Two edge-sharing triangular bipyramidal ZnO5units form a dimer, which is linked to slightly deformed FeO6octahedraviaa common edge. The resulting chains are interconnected through PO4tetrahedra to form a layer perpendicular to thebaxis. Moreover, the remaining PO4and ZnO4tetrahedra are linked together through common vertices to form tapes parallel to thecaxis and surrounding a chain of Ca2+cations to build a sheet, also perpendicular to thebaxis. The stacking of the two layers along thebaxis leads to the resulting three-dimensional framework, which defines channels in which the Ca2+cations are located, each cation being coordinated by seven oxygen atoms.


2012 ◽  
Vol 68 (6) ◽  
pp. i40-i41 ◽  
Author(s):  
Wafa Frigui ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

Single crystals of wyllieite-type silver(I) manganese(II) trisorthoarsenate(V), Ag1.09Mn3.46(AsO4)3, were grown by a solid-state reaction. The three-dimensional framework is made up from four Mn2+/Mn3+ cations surrounded octahedrally by O atoms. The MnO6 octahedra are linked through edge- and corner-sharing. Three independent AsO4 tetrahedra are linked to the framework through common corners, delimiting channels along [100] in which two partly occupied Ag+ sites reside, one on an inversion centre and with an occupancy of 0.631 (4), the other on a general site and with an occupancy of 0.774 (3), both within distorted tetrahedral environments. One of the Mn sites is also located on an inversion centre and is partly occupied, with an occupancy of 0.916 (5). Related compounds with alluaudite-type or rosemaryite-type structures are compared and discussed.


2007 ◽  
Vol 62 (4) ◽  
pp. 610-612 ◽  
Author(s):  
Ahmet Doğan ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen

The intermetallic cadmium compounds LaPdCd2 and PrNi0.951(4)Cd2 were synthesized from the elements in sealed tantalum tubes in an induction furnace. Both phases were investigated by X-ray diffraction on powders and single crystals: MgCuAl2-type, Cmcm, Z = 4, a = 431.9(1), b = 1015.7(4), c = 835.7(2) pm, wR2 = 0.0436, 326 F2 values, 16 variables for LaPdCd2 and a = 420.26(8), b = 981.0(2), c = 815.3(1) pm, wR2 = 0.0404, 604 F2 values, 17 variables for PrNi0.951(4)Cd2. A small nickel deficit was observed for the PrNi0.951(4)Cd2 crystal. The cadmium atoms build up orthorhombically distorted three-dimensional networks (Cd-Cd distances: 302 - 334 pm) that resemble the structure of hexagonal diamond, lonsdaleite. Together with the palladium (nickel) atoms, [PdCd2] and [Ni0.951(4)Cd2] networks are formed which leave distorted hexagonal channels for the rare earth atoms.


2012 ◽  
Vol 68 (4) ◽  
pp. i23-i23 ◽  
Author(s):  
Abdelghani Oudahmane ◽  
Malika El-Ghozzi ◽  
Daniel Avignant

Single crystals of Ca5Zr3F22, pentacalcium trizirconium docosafluoride, were obtained unexpectedly by solid-state reaction between CaF2and ZrF4in the presence of AgF. The structure of the title compound is isotypic with that of Sr5Zr3F22and can be described as being composed of layers with composition [Zr3F20]8−made up from two different [ZrF8]4−square antiprisms (one with site symmetry 2) by corner-sharing. The layers extending parallel to the (001) plane are further linked by Ca2+cations, forming a three-dimensional network. Amongst the four crystallographically different Ca2+ions, three are located on twofold rotation axes. The Ca2+ions exhibit coordination numbers ranging from 8 to 12, depending on the cut off, with very distorted fluorine environments. Two of the Ca2+ions occupy interstices between the layers whereas the other two are located in void spaces of the [Zr3F20]8−layer and alternate with the two Zr atoms along [010]. The crystal under investigation was an inversion twin.


2018 ◽  
Vol 74 (9) ◽  
pp. 1358-1361 ◽  
Author(s):  
Ahmed Ould Saleck ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Cyrille Mercier ◽  
Claudine Follet ◽  
...  

Single crystals of two new phosphates, sodium magnesium indium(III) tris(orthophosphate) and silver magnesium indium(III) tris(orthophosphate), were obtained from solid-state reactions. The two phosphates are isotypic and exhibit alluaudite-type structures. They are characterized by a cationic disorder of the Mg and In sites and a partial occupation of the Na and Ag sites, respectively. The structure of both phosphates is made up of chains of edge-sharing [(Mg,In)O6] octahedra extending parallel to [10\overline{1}]. Adjacent chains are linked by PO4 tetrahedra to form a three-dimensional framework delimiting two types of channels parallel to [001] in which the monovalent cations are situated. The coordination numbers of the Na+ cations are 6 and 8, and for both Ag+ cations 6. The corresponding coordination spheres are considerably distorted.


2019 ◽  
Author(s):  
Sayan Mondal ◽  
Gary Tresadern ◽  
Jeremy Greenwood ◽  
Byungchan Kim ◽  
Joe Kaus ◽  
...  

<p>Optimizing the solubility of small molecules is important in a wide variety of contexts, including in drug discovery where the optimization of aqueous solubility is often crucial to achieve oral bioavailability. In such a context, solubility optimization cannot be successfully pursued by indiscriminate increases in polarity, which would likely reduce permeability and potency. Moreover, increasing polarity may not even improve solubility itself in many cases, if it stabilizes the solid-state form. Here we present a novel physics-based approach to predict the solubility of small molecules, that takes into account three-dimensional solid-state characteristics in addition to polarity. The calculated solubilities are in good agreement with experimental solubilities taken both from the literature as well as from several active pharmaceutical discovery projects. This computational approach enables strategies to optimize solubility by disrupting the three-dimensional solid-state packing of novel chemical matter, illustrated here for an active medicinal chemistry campaign.</p>


1997 ◽  
Vol 52 (5) ◽  
pp. 663-668 ◽  
Author(s):  
B. Mertens ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of I RbCd4V3O12 and TlCd4V3O12 II have been prepared by solid state reactions in closed iron tubes. The compounds crystallize closely related to the Johillerite structure in the space group C62h- C2/c with I: a = 13.058(3); b - 13.528(3), c = 7 .0 6 0 (2 )Å , β = 114.88(2)°; II: a = 12.999(6), b = 13.527(7), c = 7.055(3) Å , β = 114.88(4)°, Z = 4. Special features are the loss of Cu2+ in order to gain an additional Cd2+ position. The crystal structure is discussed with respect to related compounds of the Johillerite type.


Author(s):  
Phan Gia Le ◽  
Huyen Tran Tran ◽  
Jong-Sook Lee ◽  
John G. Fisher ◽  
Hwang-Pill Kim ◽  
...  

AbstractCeramics based on (Na1/2B1/2)TiO3 are promising candidates for actuator applications because of large strains generated by an electric field-induced phase transition. For example, the (1−x)(Na1/2Bi1/2)TiO3-xSrTiO3 system exhibits a morphotropic phase boundary at x = 0.2–0.3, leading to high values of inverse piezoelectric constant d*33, which can be further improved by the use of single crystals. In our previous work, single crystals of (Na1/2B1/2)TiO3-SrTiO3 and (Na1/2B1/2)TiO3-CaTiO3 were grown by the solid state crystal growth technique. Growth in the (Na1/2B1/2)TiO3-SrTiO3 system was sluggish whereas the (Na1/2B1/2)TiO3-CaTiO3 single crystals grew well. In the present work, 0.8(Na1/2Bi1/2)TiO3-0.2(Sr1−xCax)TiO3 single crystals (with x = 0.0, 0.1, 0.2, 0.3, 0.4) were produced by the solid state crystal growth technique in an attempt to improve crystal growth rate. The dependence of mean matrix grain size, single crystal growth distance, and electrical properties on the Ca concentration was investigated in detail. These investigations indicated that at x = 0.3 the matrix grain growth was suppressed and the driving force for single crystal growth was enhanced. Replacing Sr with Ca increased the shoulder temperature Ts and temperature of maximum relative permittivity Tmax, causing a decrease in inverse piezoelectric properties and a change from normal to incipient ferroelectric behavior.


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