Penta-, Hepta- und Oktaiodid-Anionen in Salzen mit Erdalkalimetall-Kronenether-Kationen / Penta-, Hepta-, and Octaiodide Anions in Salts with Alkaline Earth Metal Crown Ether Cations

2010 ◽  
Vol 65 (9) ◽  
pp. 1077-1083 ◽  
Author(s):  
Christine Walbaum ◽  
Ingo Pantenburg ◽  
Gerd Meyer

Salts of alkaline earth metal cations sequestered in dibenzo-18-crown-6 (Db18c6) and benzo-15- crown-5 (B15c5), respectively, with I5−, I7− and I82− as the anions, have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. [Ca(Db18c6)(H2O)3](I5)2- (Db18c6)(H2O) (1): monoclinic, P21 (no. 4), a = 1322.1(2), b = 1849.1(2), c = 1344.0(2) pm, β = 114.70(1)◦, V = 2985.2(6) × 106 pm3, Z = 2; [Sr(B15c5)2](I7)2 (2): triclinic, P1 (no. 2), a = 973.9(5), b = 1244.0(5), c = 1293.3(5) pm, α = 115.28(1), β = 90.18(1), γ = 104.57(1)◦, V = 1360.2(10) × 106 pm3, Z = 2; [Ba(Db18c6)2]I8 (3): orthorhombic, Pbcn (no. 60), a = 1452.0(2), b = 1924.6(2), c = 1912.1(2) pm, V = 5343.3(10) × 106 pm3, Z = 4. Compound 1 contains two crystallographically independent V-shaped pentaiodide anions, I5 −, which are linked to dimers by weak interionic contacts. The unusual heptaiodide anion, I7−, in 2 can be described as a V-shaped pentaiodide unit, which is connected to a slightly widened iodine molecule to give the rare Z form. Secondary bonding distances lead to almost planar ten-membered iodine rings, which are connected through common edges to form ribbons with staircase-like folding. 3 is built of sandwich-like cations and centrosymmetric octaiodide anions, I82−. An inspection for secondary contacts reveals that the iodine substructure of 3 consists of essentially isolated octaiodide units.

2020 ◽  
Vol 235 (4-5) ◽  
pp. 137-141
Author(s):  
Maximilian K. Reimann ◽  
Rainer Pöttgen

AbstractThe copper-rich intermetallic compounds CaCu9Mg2 and SrCu9Mg2 were synthesized by induction melting of the elements and subsequent annealing in a muffle furnace. CaCu9Mg2 and SrCu9Mg2 crystallize with the TbCu9Mg2 type structure, space group P 63/mmc, which is a ternary ordered variant of CeNi3. The polycrystalline samples were characterized through their X-ray powder patterns. The CaCu9Mg2 structure was refined from single-crystal X-ray diffraction data. a = 504.13(9), c = 1622.5(3) pm, wR2 = 0.0635, 302 F2 values and 19 variables. The two striking coordination polyhedra in the CaCu9Mg2 structure are Ca@Cu18Mg2 and Mg@Cu12Mg3Ca. These polyhedra condense to layers which are stacked in ABA′B′ sequence. The X-ray data give no hint for Ca/Mg mixing.


2017 ◽  
Vol 46 (27) ◽  
pp. 8727-8735 ◽  
Author(s):  
Fabian Dankert ◽  
Kirsten Reuter ◽  
Carsten Donsbach ◽  
Carsten von Hänisch

A series of disila-crown ether complexes have been characterized by single crystal X-ray diffraction. The complex stability of different systems were studied by DFT calculations and proton NMR experiments.


2007 ◽  
Vol 62 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Olaf Reckeweg ◽  
Jay C. Molstad ◽  
Scott Levy ◽  
Francis J. DiSalvo

Single crystals of the isotypic hydrides Ba2H3X (X = Cl or Br) were obtained by solid-state reactions of Ba, NaCl, NaNH2 and metallic Na, or Ba, NH4Br and Na, respectively, in sealed, silicajacketed stainless-steel ampoules. The crystal structures of the new compounds were determined by means of single crystal X-ray diffraction. Ba2H3Cl and Ba2H3Br crystallize in a stuffed anti CdI2 structure and adopt the space group P3̄m1 (No. 164) with the lattice parameters a = 443.00(6), c = 723.00(14) pm and a = 444.92(4), c = 754.48(14) pm, respectively. The hydride positions are derived by crystallographic reasoning and with the help of EUTAX calculations. The results are compared with known data for binary and ternary alkaline earth metal hydrides.


1976 ◽  
Vol 31 (12) ◽  
pp. 1604-1606 ◽  
Author(s):  
Hk. Müller-Buschbaum ◽  
W. Schmachtel

Mixed crystals of the formulae CaGaAlO4 (1) and CaGa0.5Al1.5O4 (2) were investigated by X-ray single crystal work. 1 shows a tetrahedral orientation like that of CaGa2O4 (monokl.), 2 another one of CaAl2O4. A discussion of the different polyhedral arrangement of the stuffed tridymite structures is given.


Author(s):  
Igor Oshchapovsky ◽  
Volodymyr Pavlyuk ◽  
Grygoriy Dmytriv ◽  
Alexandra Griffin

The structure of lanthanum tetrazinc, LaZn4, has been determined from single-crystal X-ray diffraction data for the first time, approximately 70 years after its discovery. The compound exhibits a new structure type in the space groupCmcm, with one La atom and two Zn atoms occupying sites withm2msymmetry, and one Zn atom occupying a site with 2.. symmetry. The structure is closely related to the BaAl4, La3Al11, BaNi2Si2and CaCu5structure types, which can be presented as close-packed arrangements of 18-vertex clusters, in this case LaZn18. The kindred structure types contain related 18-vertex clusters around atoms of the rare earth or alkaline earth metal.


Author(s):  
Jeffrey A. Rood ◽  
Ashley L. Huttenstine ◽  
Zachery A. Schmidt ◽  
Michael R. White ◽  
Allen G. Oliver

Reaction of alkaline earth metal salts with diphenylphosphinic acid in dimethylformamide solvent afforded four coordination polymers: [Mg3(O2PPh2)6(DMF)2]·2DMF (I), [Ca(O2PPh2)2(DMF)2] (II), [Sr(O2PPh2)2(DMF)2] (III) and [Ba(O2PPh2)2(DMF)2] (IV) (where DMF isN,N-dimethylformamide). Single-crystal X-ray diffraction revealed that all four compounds produce linear chain structures in the solid state, with the Ca, Sr and Ba forming isostructural crystals. The bulk materials were characterized by FT–IR and1H NMR spectroscopy and elemental analyses.


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