Generation of optical activity through solid state reaction of a racemic mixture that crystallizes in a chiral space group

1987 ◽  
Vol 28 (41) ◽  
pp. 4789-4792 ◽  
Author(s):  
Miguel Garcia-Garibay ◽  
John R. Scheffer ◽  
James Trotter ◽  
Fred Wireko
1995 ◽  
Vol 50 (1) ◽  
pp. 51-55 ◽  
Author(s):  
F.-D. Martin ◽  
Hk. Müller-Buschbaum

Single crystals of NaFe3V3O12 have been prepared by solid state reaction below the melting point of the reaction mixture. This compound is isotypic to the mineral Howardevansite but shows lower triclinic symmetry, space group C11–P1, a = 6.757(2), b = 8.155(2), c = 9.816(3) Å, α = 106.05(2), β = 104.401(9), γ = 102.09(2)°, Z = 2. The acentric space group is caused by the sodium positions, all other atoms comply with the space group P̄ of Howardevansite. The different ions are coordinated by O2- forming VO4 tetrahedra, FeO6 octahedra, trigonal FeO5 bipyramids and irregular NaO5 and NaO7 polyhedra, respectively. The crystal chemistry is discussed with respect to Howardevansite.


1994 ◽  
Vol 9 (2) ◽  
pp. 146-147 ◽  
Author(s):  
C. Colbeau-Justin ◽  
A. Elfakir ◽  
M. Quarton

A new titanate K2ZnTiO4 has been synthesized by solid-state reaction. This compound is isostructural with K2ZnGeO4, space group Pca21, Z=8. Unit-cell parameters were determined: a=11.3352(6) Å, b=5.6352(5) Å, c=16.0125(13) Å, and V=1022.8(3) Å3. Powder diffraction data are reported.


1978 ◽  
Vol 33 (2) ◽  
pp. 146-148 ◽  
Author(s):  
Hk. Müller-Buschbaum ◽  
M. Harder

Single crystals of the compound Ba2Fe11Al11O34 were prepared by solid state reaction (1700 °C) of BaO-Fe2O3-Al2O3 mixtures. The crystal structure was investigated by X-ray data (space group D46h-P63/mmc, lattice constants: a = 565.3, c = 2281.0 pm). Ba2Fe11Al11O34 is isotypic with Na2O · 11 Al2O3, the structure of β-alumina


RSC Advances ◽  
2017 ◽  
Vol 7 (29) ◽  
pp. 17612-17619 ◽  
Author(s):  
Weiguang Ran ◽  
Lili Wang ◽  
Qingzhi Liu ◽  
Guangzeng Liu ◽  
Dan Qu ◽  
...  

Mn2+-activated CdAl2O4 phosphors with the new structure of space group R3̄ (no. 148) have been prepared by a high-temperature solid-state reaction and their luminescence properties have been investigated in detail.


2015 ◽  
Vol 71 (10) ◽  
pp. 1255-1258 ◽  
Author(s):  
Said Ouaatta ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

The title compound, SrNi2Fe(PO4)3, synthesized by solid-state reaction, crystallizes in an ordered variant of the α-CrPO4structure. In the asymmetric unit, two O atoms are in general positions, whereas all others atoms are in special positions of the space groupImma: the Sr cation and one P atom occupy the Wyckoff position 4e(mm2), Fe is on 4b(2/m), Ni and the other P atom are on 8g(2), one O atom is on 8h(m) and the other on 8i(m). The three-dimensional framework of the crystal structure is built up by [PO4] tetrahedra, [FeO6] octahedra and [Ni2O10] dimers of edge-sharing octahedra, linked through common corners or edges. This structure comprises two types of layers stacked alternately along the [100] direction. The first layer is formed by edge-sharing octahedra ([Ni2O10] dimer) linked to [PO4] tetrahedraviacommon edges while the second layer is built up from a strontium row followed by infinite chains of alternating [PO4] tetrahedra and FeO6octahedra sharing apices. The layers are held together through vertices of [PO4] tetrahedra and [FeO6] octahedra, leading to the appearance of two types of tunnels parallel to thea- andb-axis directions in which the Sr cations are located. Each Sr cation is surrounded by eight O atoms.


Author(s):  
Adam Bouraima ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Thomas Makani ◽  
Lahcen El Ammari

The title compound, Na2Co2Fe(PO4)3, was synthesized by a solid-state reaction. This new stoichiometric phase crystallizes in an alluaudite-like structure. In this structure, all atoms are in general positions except for four atoms which are located at the special positions of theC2/cspace group. One Co atom, one P and one Na atom are all located on Wyckoff position 4e(2), while the second Na atom is located on an inversion centre 4a(-1). The other Co and Fe atoms occupy a general position with a statistical distribution. The open framework results from [(Co,Fe)2O10] units of edge-sharing [(Co,Fe)O6] octahedra, which alternate with [CoO6] octahedra that form infinite chains running along the [10-1] direction. These chains are linked together through PO4tetrahedra by the sharing of vertices so as to build layers perpendicular to [010]. The three-dimensional framework is accomplished by the stacking of these layers, leading to the formation of two types of tunnels parallel to [010] in which the Na+cations are located, each cation being surrounded by eight O atoms.


2007 ◽  
Vol 62 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Nachiappan Arumugam ◽  
Eva-Maria Peters ◽  
Martin Jansen

A new potassium molybdenum oxide, K6Mo10O33, was synthesized by solid state reaction from the appropriate quantities of pre-dried MoO3 and K2MoO4, fired at around 650 °C for 2 d. The structure has been solved by using single crystal X-ray diffraction. The compound adopts the space group P1, with the lattice constants a = 7.7100(5), b = 11.9659(8), c = 17.1321(12) A° , α = 86.42 (10), β = 77.18(10), γ = 74.14(10)°. The structure is built up of infinite chains of edge-sharing MoO6 octahedra and groups of four MoO6 octahedra forming Mo4O17 units. These sub-units are connected together by common vertices.


2021 ◽  
Author(s):  
Hongbo Gao ◽  
Ruijiao Chen ◽  
kewang zhang ◽  
Ailijiang Abudurusuli ◽  
Kangrong Lai ◽  
...  

A new fluorine-contained chalcohalide, Ba4GaS4F3, has been synthesized by conventional high-temperature solid-state reaction. The compound crystallizes in the centrosymmetric space group I41/a with a = b = 16.628 (5) Å,...


RSC Advances ◽  
2019 ◽  
Vol 9 (44) ◽  
pp. 25358-25367 ◽  
Author(s):  
Hanen Ghoudi ◽  
Souad Chkoundali ◽  
Zeineb Raddaoui ◽  
Abdelhedi Aydi

In this paper, the synthesis of Ca0.1Na0.9Ti0.1Nb0.9O3 (CNTN) ceramic by a solid-state reaction is reported. The results of Rietveld refinement of X-ray diffraction patterns at room temperature showed a pure tetragonal perovskite (P4mm space group).


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