Syntheses and Crystal Structures of the Two New Polychalcogenides [Mn(C6H14N2)3]Se6 and [Mn(C6H14N2)3]2[C6H16N2](TeSe2)2Se

2004 ◽  
Vol 59 (6) ◽  
pp. 629-634 ◽  
Author(s):  
Frank Wendland ◽  
Christian Näther ◽  
Wolfgang Bensch

The solvothermal reaction of MnCl2·4 H2O, K2Se3 and Se in trans-cyclohexane-1,2-diamine (chxn) at 433 K yields dark blue crystals of [Mn(chxn)3]Se6 (1), and the reaction of MnCl2 ・4 H2O, K2Se3 and Te under similar conditions gives dark blue crystals of [Mn(chxn)3]2[H2chxn](TeSe2)2Se (2). While compound (1) crystallises in the orthorhombic space group Pbcn with the lattice parameters a = 13.7017(9), b = 19.9073(8) and c = 10.8058(5)Å , compound (2) crystallises in the monoclinic space group P21 with the lattice parameters a = 9.4396(6), b = 24.2450(2), c = 12.8170(8) Å and β =91.6(1)◦. In both structures discrete complex cations and polychalcogenide anions are found. In (1) the Se62− anions form a pseudo-layer arrangement with nearly rectangular pores. The complex cations are encapsulated by the arrangement of the Se62− anions. Some short distances between the amino groups of the ligands and the anions indicate weak hydrogen bonding. In compound (2) two independent [Mn(chxn)3]2+ and one unique H2chxn dications, two unique TeSe22− as well as one Se2− dianion coexist. The two complex cations exhibit different conformations. One of the two TeSe22− anions has the di-protonated chxn molecule in the neighbourhood and short Se···H separations indicate weak hydrogen bonding. The isolated Se2− ion is located above the ring of the di-protonated trans-cyclohexane-1,2-diamine molecule and again a short Se···H separation may be due to a weak hydrogen bond. Compound (1) decomposes in a single step when heated in an Ar atmosphere. In contrast, the thermal decomposition of compound (2) is complex and at least five different steps can be identified.

1997 ◽  
Vol 50 (2) ◽  
pp. 123
Author(s):  
Margaret A. Brimble ◽  
Andrew Johnston ◽  
Trevor W. Hambley ◽  
Peter Turner

The structures of (3S*,4S*,5S*,6S*)-3,4-epoxy-1,7-dioxaspiro[5.5]undecan-5-ol (2), (3R*,5S*,6S*)-1,7- dioxaspiro[5.5]undecane-3,5-diyl diacetate (4) and (4S*,5S*,6S*)-1,7-dioxaspiro[5.5]undecane-4,5-diol (5) have been determined by X-ray crystallography. The unsubstituted tetrahydropyran ring in (2) adopts an axial position with respect to the epoxy-substituted ring and the hydroxy group at C5 is syn to the epoxide group. Intermolecular hydrogen bonding is observed between the C5 hydroxy group and O1. The two six-membered rings in (4) adopt chair conformations and the two acetate groups adopt 1,3-diaxial positions. The C5 hydroxy group in (5) assumes an axial position anti to the C-O bond of the neighbouring ring whilst 4-OH occupies an equatorial position. Intermolecular hydrogen bonding is also observed between 4-OH and 5-OH. Compound (2), C9H14O4, M 186·21, crystallized in the monoclinic space group P 21/c with a 7·867(1), b 12·2060(9), c 9·3676(8) Å, b 102·744(8), V 877·4(1) Å 3 and No 1163 [I > 2·5s (I)], R 0·031, Rw 0·035. Compound (4), C13H20O6, M 272·30, crystallized in the triclinic space group P 1 with a 9·902(1), b 11·0024(9), c 6·9183(5)Å, a 104·078(8), b 96·769(9), g 101·980(8), V 703·8(1) Å 3 , No 1657 [I > 2·5s(I)], R 0·047, Rw 0·044. Compound (5), C9H16O4, M 188·22, crystallized in the orthorhombic space group Pbca with a 25·504(3), b 8·909(2), c 8·038(2) Å, V 1826·4(5) QA 3 , No 1096 [I > 2·5s(I)], R 0·030, Rw 0·030.


1996 ◽  
Vol 49 (7) ◽  
pp. 775 ◽  
Author(s):  
TW Hambley ◽  
TW Hambley ◽  
KG Lewis ◽  
KG Lewis ◽  
DJ Tucker ◽  
...  

Reaction of olean-12-ene-3β,16β,22α,28-tetrol ( chichipegenin ) (1) with methyl orthoformate gives the 16β,22α,28-orthoformate (2). Acetylation of the ortho ester followed by hydrolysis gives the tetrol 3β-monoacetate (5). It is shown that intramolecular hydrogen bonding occurs in the tetrol (1) and the 3β-monoacetate (5) in non-polar solvents. X-Ray crystallographic data on the tetrol and its tetraacetate (4) are reported. The tetrol,C30H50O4, M 474.72, crystallized in the orthorhombic space group P 212121 with a 12.363(6), b 31.888(3), c 6.962(3) Ǻ, V 2745(1) Ǻ3, Dc(Z = 4) 1.149 g cm-3, N = N(unique) 2394, No 1878 [I > 1.5σ(I)], Nvar 500; R 0.038, Rw 0.040. The tetraacetate , C38H58O8, M 642.87, crystallized in the monoclinic space group P 21, with a 10.603(2), b 16.569(1), c 10.814(1) Ǻ, β 98.72(1)°, V 1877.9(4) Ǻ3, Dc(Z = 2) 1.137g cm-3 N 3090, Rmerge 4.67% for N(unique) 2917, No 2663 [I > 2.5σ(I)], Nvar 414; R 0.053, Rw 0.050.


2000 ◽  
Vol 53 (9) ◽  
pp. 755 ◽  
Author(s):  
Kristian H. Sugiyarto ◽  
Marcia L. Scudder ◽  
Donald C. Craig ◽  
Harold A. Goodwin

Essentially high-spin [Fe(bpp)2][NCS]2·2H2O and [Fe(bpp)2][NCSe]2 (bpp = 2,6-bis(pyrazol-3-yl)pyridine) were isolated from an aqueous reaction mixture. Both salts undergo an abrupt transition to low spin below room temperature, that for the thiocyanate occurring in two steps and the high-spin Æ low-spin Æ high-spin cycle being accompanied by hysteresis in both steps. Recrystallization of the salts from nitromethane yielded a mixture from which bright yellow crystals were separated for structure determination. In addition, from the recrystallized selenocyanate, deep red-brown crystals of composition [Fe(bpp)2][NCSe]2·H2O·0.25 CH3NO2 were obtained. Recrystallized [Fe(bpp)2][NCS]2·2H2O and [Fe(bpp)2][NCSe]2 were identified as high spin with average Fe–N distances of 2.16 and 2.17 Å, respectively. In the unit cell of [Fe(bpp)2][NCSe]2·H2O·0.25 CH3NO2, there are four independent iron atoms, three identified as low spin and the fourth as high spin. All salts crystallize in a layer-type array involving edge-to-face and face-to-face aryl–aryl-type interactions. Hydrogen bonding between pyrazole >NH groups, anions and solvate molecules is observed. The structure of the uncoordinated ligand was also determined, the molecule being found in a planar arrangement with thecis–cis configuration for the pyrazolyl groups relative to the central pyridyl and the >NH group being at the N 2 atom. Hydrogen bonding involving the >NH groups leads to stepped stacks of molecules. The principal difference in the geometry of coordinated and free bpp molecules is a contraction in the angles about the interannular bridges in the chelate rings. [Fe(bpp)2][NCS]2·2H2O: triclinic, space group P1–, a 8.302(6), b 8.446(6), c 21.531(13) Å, a 78.78(5), b 82.80(5), g 89.85(4)˚, Z 2. [Fe(bpp)2][NCSe]2: triclinic, space group P1–, a 8.354(4), b 8.409(4), c 19.918(9) Å, a 87.02(3), b 83.15(3), g 88.86(3)˚, Z 2. [Fe(bpp)2][NCSe]2·H2O·0.25 CH3NO2: monoclinic, space group Pn, a 16.425(12), b 20.774(9), c 16.933(14) Å, b 90.91(4)˚, Z 8. Uncoordinated bpp: orthorhombic, space group Pna21, a 8.075(3), b 22.479(9), c 5.525(1) Å, b Z 4.


2000 ◽  
Vol 33 (2) ◽  
pp. 213-217 ◽  
Author(s):  
J. Kusz ◽  
H. Böhm ◽  
E. Talik

The variations of the lattice parameters of Gd3T(T= Ni, Rh, Irx) single crystals with temperature were measured in the range 10–300 K. The compounds with Ni and Rh crystallize in the orthorhombic space groupPnma, but the compound with Ir crystallizes as Gd5Ir2in the monoclinic space groupA2/a. The three compounds exhibit an anomalous anisotropic spontaneous magnetostriction below the magnetic ordering temperature.


2019 ◽  
Vol 75 (1) ◽  
pp. 54-60
Author(s):  
Gerhard T. Roodt ◽  
Bhawna Uprety ◽  
Demetrius C. Levendis ◽  
Charmaine Arderne

The acidity of the amine H atoms and the consequent salt formation ability of ethylenedinitramine (EDNA) were analyzed in an attempt to improve the thermal stability of EDNA. Two short-chain alkanediamine bases, namely propane-1,3-diamine and butane-1,4-diamine, were chosen for this purpose. The resulting salts, namely propane-1,3-diaminium N,N′-dinitroethylenediazanide, C3H12N2 2+·C2H4N4O4 2−, and butane-1,4-diaminium N,N′-dinitroethylenediazanide, C4H14N2 2+·C2H4N4O4 2−, crystallize in the orthorhombic space group Pbca and the monoclinic space group P21/n, respectively. The resulting salts display extensive hydrogen-bonding networks because of the presence of ammonium and diazenide ions in the crystal lattice. This results in an enhanced thermal stability and raises the thermal decomposition temperatures to 202 and 221 °C compared to 180 °C for EDNA. The extensive hydrogen bonding present also plays a crucial role in lowering the sensitivity to impact of these energetic salts.


2012 ◽  
Vol 67 (7) ◽  
pp. 651-656 ◽  
Author(s):  
Prashanth W. Menezes ◽  
Thomas F. Fässler

Two novel selenoarsenates, K3AsSe4 and K4As2Se5, were synthesized by the mild solvothermal reaction of potassium carbonate and arsenic and selenium powder in the presence of superheated ethylenediamine and structurally characterized by single-crystal X-ray diffraction. K3AsSe4 crystallizes in the orthorhombic space group Pnma (no. 62) with a = 9:4169(4), b = 10:9695(5), c = 9:7568(8) Å, Z = 4 and V = 1007:86(10) Å3 and contains [AsSe4]3- anions with pentavalent arsenic. K4As2Se5 crystallizes in the monoclinic space group P21/n (no. 14) with a = 7:6167(2), b = 22:8733(4), c = 8:4687(2) Å, b = 107:241(2)°, Z = 4 and V = 1409:14(5) Å3, and shows isolated [As2Se5]4- anions. The most prominent feature of the latter anions is the presence of arsenic in two different formal oxidation states (+4/+2) due to the presence of an As-As bond.


1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).


2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.


2012 ◽  
Vol 67 (2) ◽  
pp. 127-22
Author(s):  
Anna J. Lehner ◽  
Korina Kraut ◽  
Caroline Röhr

Mixed sulfido/oxidomolybdate anions [MoOxS4−x]2− (x = 1, 2, 3) have been prepared by passing H2S gas through a solution of oxidomolybdates. The alkali salts of K+, Rb+, Cs+, and NH+4 precipitate as crystalline salts from these solutions depending on the pH, the polarity of the solvent, the educt concentrations and the temperature. Their structures have been determined by means of X-ray single-crystal diffraction data. All trisulfidomolybdates A2[MoOS3] (A = NH4/K/Rb/Cs) are isotypic with the tetrasulfido salts, exhibiting the β -K2[SO4] type (orthorhombic, space group Pnma, Z = 4; for A = Rb: a = 940.62(4), b = 713.32(4), c = 1164.56(5) pm, R1 = 0.0281). In contrast, the disulfidomolybdates exhibit a rich crystal chemistry, forming three different structure types depending on the preparation conditions and the size of the A cation: All four cations form salts crystallizing with the (NH4)2[WO2S2] structure type (monoclinic, space group C2/c, Z = 4, for A = Rb: a = 1144.32(11), b = 732.60(4), c = 978.99(10) pm, β = 120.324(7)°, R1 = 0.0274). For the three alkali metal cations a second polymorph with a new structure type (monoclinic, space group P21/c, Z = 4) is observed in addition (for A = Rb: a = 674.83(2), b = 852.98(3), c = 1383.10(9) pm, β = 115.19(1)°, R1 = 0.0216). The cesium salt also crystallizes with a third modification of another new structure type (orthorhombic, space group Pbcn, Z = 4, a = 915.30(6), b = 777.27(7), c = 1120.02(7) pm, R1 = 0.0350). Only for K, an anhydrous monosulfidomolybdate could be obtained (K2[MoO4] structure type, monoclinic, space group C2/m, Z = 4, a = 1288.7(3), b = 615.7(2), c = 762.2(1) pm, β = 109.59(1)°, R1 = 0.0736). The intramolecular chemical bonding in the molybdate anions is discussed and compared with the respective vanadates. Hereby aspects like bond lengths, bond strengths and force constants derived from Raman spectroscopy, are taken into account. Especially for the polymorphic disulfido salts, in-depth analyses of the local coordination numbers and the packing of the ions are presented. The gradual bathochromic shift of the crystal color with increasing S content and increasing size of the counter cations A and molar volumes (for the polymorphic forms), respectively, is in accordance with the increase of the experimental (UV/Vis spectroscopy) and calculated (FP-LAPW band structure theory) band gaps.


2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).


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