Lanthanide Ion Complexes of Calixarenes. VII. Bimetallic Lanthanide Complexes of p-t-Butylcalix[8]arene From Dimethyl Sulfoxide Solutions

1991 ◽  
Vol 44 (9) ◽  
pp. 1237 ◽  
Author(s):  
JM Harrowfield ◽  
MI Ogden ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Dimethyl Sulfoxide ◽  
Lanthanide Complexes ◽  
Complex Molecule ◽  
Asymmetric Unit ◽  
Lanthanide Ion ◽  
X Ray ◽  
Twofold Axis ◽  
Lanthanide Atoms ◽  
Similar Complex

Reaction of Ln (ClO4)3.x dmso ( dmso denotes dimethyl sulfoxide ) with a warm p-t- butylcalix [8] arene (L) slurry in acetone/ dmso yields crystalline 2:1 Ln/ligand adducts, characterized as dmso olvates and established to be [Ln2(L-6H)( dmso )5].~2dmso by single- crystal X-ray studies at c. 295 K for Ln = La, Eu , Tm and Lu. All complexes are isomorphous , orthorhombic, Pcnb, a ≈ 34, b ≈ 23, c ≈ 14 Ǻ, Z 4, with a similar complex molecule in each case, one half comprising the asymmetric unit; the second half is generated by a crystallographic twofold axis. The two lanthanide atoms are encompassed by the macrocycle and are eight coordinate, involving phenolic and dmso O-donor atoms, five of the former (two bridging) and three of the latter (one bridging). The array closely resembles that found in analogous dmf solvent adducts: the bridging dmso lies on the crystallographic twofold axis through the complex, its peripheral atoms being modelled by disorder.

Lanthanide Ion Complexes of Calixarenes. VIII. Bimetallic Lanthanide Complexes of p-t-Butylcalix[8]arene From Dimethylformamide Solutions

1991 ◽  
Vol 44 (9) ◽  
pp. 1249 ◽  
Author(s):  
JM Harrowfield ◽  
MI Ogden ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Lanthanide Complexes ◽  
Complex Molecule ◽  
Lanthanide Ion ◽  
X Ray

Reaction of lanthanide(III) ion p- toluenesulfonates with a warm p-t- butylcalix [8] arene (L) solution in dmf/triethylamine ( dmf denotes N,N- dimethylformamide ), yields crystalline 2 : 1 Ln/ligand adducts, as dmf solvates: [Ln2(L-6H)( dmf )5]. xdmf , Ln = La, Pr, Lu and Eu (previously recorded; 2 phases) have been characterized by single-crystal X-ray studies; all phases are triclinic but only the praseodymium and α-form of the europium derivative are isostructural : Ln = La, Pr, α- Eu have Z = 2 formula units, while Ln = β- Eu , Lu have Z = 4. In all cases, the stoichiometry of the complex molecule is the same and the same as that of the dmso adducts recorded in the previous paper, with similar ligand dispositions.

Structure and Stereochemistry of Adducts of Tris(dipivaloylmethanato)europium(III), Eu(dpm)3, with Some Dipolar Aprotic Unidentate O-Donors

2020 ◽  
Vol 73 (6) ◽  
pp. 455
Author(s):  
Eric J. Chan ◽  
Jack M. Harrowfield ◽  
Brian W. Skelton ◽  
Alexandre N. Sobolev ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Dimethyl Sulfoxide ◽  
The Other ◽  
Asymmetric Unit ◽  
X Ray ◽  
Metal Atoms ◽  
Oxygen Donor ◽  
Trigonal Prismatic

Single crystal X-ray structural characterisations are reported for adducts of the form [(L-O)Eu(O,O′-dpm)3] obtained by the crystallisation of tris(dipivaloylmethanato)europium(iii) (dpm=[HC(C(tBu).CO)2]−) from an array of dipolar aprotic oxygen-donor solvents L (L=N-methylpyrrolidinone (nmp), trimethylphosphate, (MeO)3PO, (tmp), hexamethylphosphoramide (hmpa), dimethylacetamide (dma), dimethyl sulfoxide (dmso), and the bidentate octamethylpyrophosphoramide (ompa). In all adducts, the resulting arrays contain seven-coordinate metal atoms, which adopt two different isomeric forms of the mono-capped trigonal prismatic stereochemistry, the L=dma and dmso adducts corresponding to one type, nmp and tmp the other. The adduct formed with ompa behaves as a pair of discrete metal environments bridged by the O-ompa-O′ ligand, thus; [(dpm-O,O′)3Eu(O-ompa-O′)Eu(O,O′-dpm)3], and is found in two forms, one in which both Eu environments is of the tmp type, the other of the dmso/dma type. In the hmpa adduct, the asymmetric unit of the structure is a disordered composite of both types. In none of the adducts is there any further solvation beyond coordination of a single L.

scholarly journals Crystal structure of bis{(3,5-dimethylpyrazol-1-yl)dihydro[3-(pyridin-2-yl)pyrazol-1-yl]borato}iron(II)

2020 ◽  
Vol 76 (8) ◽  
pp. 1266-1270
Author(s):  
Sascha Ossinger ◽  
Christian Näther ◽  
Felix Tuczek
Keyword(s):  
Spin Crossover ◽  
Magnetic Measurements ◽  
Complex Molecule ◽  
High Spin State ◽  
Methyl Groups ◽  
Asymmetric Unit ◽  
Pure Sample ◽  
X Ray ◽  
Classical Hydrogen Bond

The structure determination of [Fe(C13H15BN5)2] was undertaken as part of a project on the modification of the recently published spin-crossover (SCO) complex [Fe{H2B(pz)(pypz)}2] (pz = pyrazole, pypz = pyridylpyrazole). To this end, a new ligand was synthesized in which two additional methyl groups are present. Its reaction with iron trifluoromethanesulfonate led to a pure sample of the title compound, as proven by X-ray powder diffraction. The asymmetric unit consists of one complex molecule in a general position. The FeII atom is coordinated by two tridentate N-binding {H2B(3,5-(CH3)2-pz)(pypz)}− ligands. The Fe—N bond lengths range between 2.1222 (13) and 2.3255 (15) Å, compatible with FeII in the high-spin state, which was also confirmed by magnetic measurements. Other than a very weak C—H...N non-classical hydrogen bond linking individual molecules into rows extending parallel to [010], there are no remarkable intermolecular interactions.

scholarly journals Diosgenin hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o2357-o2357 ◽  
Author(s):  
María-Guadalupe Hernández Linares ◽  
Sylvain Bernès ◽  
Marcos Flores-Alamo ◽  
Gabriel Guerrero-Luna ◽  
Anselmo A. Martínez-Gallegos
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Dimethyl Sulfoxide ◽  
Starting Material ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
X Ray ◽  
Hydroxy Groups ◽  
Hydrogen Bonded

Diosgenin [or (22R,25R)-spirost-5-en-3β-ol] is the starting material of the Marker degradation, a cheap semi-synthesis of progesterone, which has been designated as an International Historic Chemical Landmark. Thus far, a single X-ray structure for diosgenin is known, namely its dimethyl sulfoxide solvate [Zhanget al.(2005).Acta Cryst.E61, o2324–o2325]. We have now determined the structure of the hemihydrate, C27H42O3·0.5H2O. The asymmetric unit contains two diosgenin molecules, with quite similar conformations, and one water molecule. Hydroxy groups in steroids and water molecules form O—H...O hydrogen-bondedR54(10) ring motifs. Fused edge-sharingR(10) rings form a backbone oriented along [100], which aggregates the diosgenin molecules in the crystal structure.

scholarly journals Single-crystal neutron diffraction study of β-Cs3(HSO4)2[H2−x (S x P1−x )O4] (x ≃ 0.5) at 15 K

1999 ◽  
Vol 55 (3) ◽  
pp. 285-296 ◽  
Author(s):  
S. M. Haile ◽  
W. T. Klooster
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Local Structure ◽  
Unit Cell Volume ◽  
Structural Models ◽  
Neutron Diffraction Study ◽  
Unit Cell ◽  
Asymmetric Unit ◽  
X Ray ◽  
Anisotropic Displacement Parameters

The structure of β-Cs3(HSO4)2[H2−x (S x P1−x )O4] has been examined by single-crystal neutron diffraction at 15 K. The compound crystallizes in space group C2/c and contains four formula units in the unit cell, with lattice parameters a = 19.769 (9), b = 7.685 (2), c = 8.858 (3) Å and β = 100.60 (4)°. Refinement of P, S and H site occupancies indicated that the value of x (in the stoichiometry) is 0.500 (6). This, together with the unit-cell volume of 1322.8 (14) Å3, implies a density of 3.463 Mg m−3. The structure contains zigzag rows of XO4 anions, where X = P or S, that alternate, in a checkerboard fashion, with zigzag rows of Cs cations. Moreover, there is one proton site, H(3), with an occupancy of 0.25 and one X-atom site, X(1), that is occupied by 0.5 P and 0.5 S. These features are in general agreement with a previous X-ray structure determination carried out at 298 K. In contrast to the X-ray study, however, it was found that two different structural models adequately fit the diffraction data. In the first model, the proton vacancies and the P atoms were assumed to be randomly distributed over the H(3) and X(1) sites, respectively, and to have no impact on the local structure. In the second model, several atoms were assigned split occupancies over two neighboring sites, to reflect the presence or absence of a proton vacancy, and the presence of P or S on the X(1) site. Refinement assuming the first model, in which anisotropic displacement parameters for 12 of 14 atom sites in the asymmetric unit were employed, yielded residuals w R(F 2) = 0.084 and w R(F) = 0.038. For the second model, in which anisotropic displacement parameters were utilized for only the five atoms that were not split relative to the first model, the residuals were w R(F 2) = 0.081 and w R(F) = 0.036.

The Rare Earth(III) Nitrate Dimethyl Sulfoxide Adducts [( dmso )nLn(O2NO)3]

1996 ◽  
Vol 49 (9) ◽  
pp. 997 ◽  
Author(s):  
LI Semenova ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Dimethyl Sulfoxide ◽  
Metal Atom ◽  
Metal Ion ◽  
Room Temperature ◽  
X Ray ◽  
The Subject ◽  
Ion Radius ◽  
The Rare Earth

Adducts [( dmso )nLn(O2NO)3], obtained by the crystallizatior , of lanthanoid (III) nitrate ( Ln (NO3)3.-xH2O) with excess dimethyl sulfoxide (' dmso ') in methanol or ethanol, have been the subject of a series of room-temperature single-crystal X-ray studies, defining more clearly the manner in which stoichiometry and structure systematically vary with change in metal ion radius. All complexes studied are mononuclear, the metal ion being complexed by three bidentate nitrate ligands and a number of dmso ligands , four for La-Sm and three beyond. The array La- Sm is monoclinic C2/c, a ≈ 14.9, b ≈ 15.5, c ≈ 15.5 Ǻ, β ≈ 108.4°, Z = 4 f.u .; the metal atom is disposed on a crystallographic 2 axis, which also passes through one of the nitrate groups. The series Eu -Tm (inclusive also of Y) is monoclinic, P21/n, a ≈ 11.5, b ≈ 12.7, c ≈ 13.6 Ǻ, β ≈ 100°, Z = 4 f.u ., while Yb and Lu are also monoclinic, P21/c, a ≈ 10.0, b ≈ 12.6, c ≈ 16 Ǻ, β ≈ 100.6°, Z = 4 f.u.

scholarly journals Crystal structures of cristobalite-type and coesite-type PON redetermined on the basis of single-crystal X-ray diffraction data

2015 ◽  
Vol 71 (11) ◽  
pp. 1325-1327 ◽  
Author(s):  
Maxim Bykov ◽  
Elena Bykova ◽  
Vadim Dyadkin ◽  
Dominik Baumann ◽  
Wolfgang Schnick ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Crystal Structures ◽  
Rotation Axis ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Determinations ◽  
Anisotropic Displacement Parameters

Hitherto, phosphorus oxonitride (PON) could not be obtained in the form of single crystals and only powder diffraction experiments were feasible for structure studies. In the present work we have synthesized two polymorphs of phosphorus oxonitride, cristobalite-type (cri-PON) and coesite-type (coe-PON), in the form of single crystals and reinvestigated their crystal structures by means of in house and synchrotron single-crystal X-ray diffraction. The crystal structures ofcri-PON andcoe-PON are built from PO2N2tetrahedral units, each with a statistical distribution of oxygen and nitrogen atoms. The crystal structure of thecoe-PON phase has the space groupC2/cwith seven atomic sites in the asymmetric unit [two P and three (N,O) sites on general positions, one (N,O) site on an inversion centre and one (N,O) site on a twofold rotation axis], while thecri-PON phase possesses tetragonalI-42dsymmetry with two independent atoms in the asymmetric unit [the P atom on a fourfold inversion axis and the (N,O) site on a twofold rotation axis]. In comparison with previous structure determinations from powder data, all atoms were refined with anisotropic displacement parameters, leading to higher precision in terms of bond lengths and angles.

scholarly journals Redetermination of Dy3Ni from single-crystal X-ray data

2013 ◽  
Vol 69 (11) ◽  
pp. i80-i80
Author(s):  
Volodymyr Levytskyy ◽  
Volodymyr Babizhetskyy ◽  
Bohdan Kotur ◽  
Volodymyr Smetana
Keyword(s):  
Single Crystal ◽  
Structure Type ◽  
Site Symmetry ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wyckoff Position ◽  
Tricapped Trigonal Prism ◽  
Anisotropic Displacement Parameters

The classification of the title compound, tridysprosium nickel, into the Fe3C (or Al3Ni) structure type has been deduced from powder X-ray diffraction data with lattice parameters reported in a previous study [Lemaire & Paccard (1967).Bull. Soc. Fr. Mineral. Cristallogr.40, 311–315]. The current re-investigation of Dy3Ni based on single-crystal X-ray data revealed atomic positional parameters and anisotropic displacement parameters with high precision. The asymmetric unit consists of two Dy and one Ni atoms. One Dy atom has site symmetry .m. (Wyckoff position 4c) and is surrounded by twelve Dy and three Ni atoms. The other Dy atom (site symmetry 1, 8d) has eleven Dy and three Ni atoms as neighbours, forming a distorted Frank–Kasper polyhedron. The coordination polyhedron of the Ni atom (.m., 4c) is a tricapped trigonal prism formed by nine Dy atoms.

On Attempts to Synthesize Lanthanide Complexes of the Dianionic Fluorenyl-alkoxo Ligand [C13H8-cyclo-C6H10-O]2-. Crystal Structure of (C13H9-cyclo-C6H10-O)LaI2(DME)2

2003 ◽  
Vol 58 (5) ◽  
pp. 389-394 ◽  
Author(s):  
Alexander A. Trifonov ◽  
Mikhail N. Bochkarev ◽  
Herbert Schumann ◽  
Sebastian Dechert
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Ir Spectra ◽  
Single Crystal ◽  
Lanthanide Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Elemental Analyses ◽  
C Nmr

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.

Serendipitous Isolation of a Trinuclear Silver Complex Containing a Bridging Tridentate Cyanide

1997 ◽  
Vol 50 (12) ◽  
pp. 1195 ◽  
Author(s):  
Chris M. Hartshorn ◽  
Peter J. Steel
Keyword(s):  
Single Crystal ◽  
Silver Complex ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Cyanide Ion ◽  
Maximum Dimension ◽  
X Ray ◽  
Nitrate Anions ◽  
Silver Atoms

The X-ray structure of a single crystal of a complex of formula C34H33Ag3N15O6 is described (P 21/c, Z4, a 10·943(1), b 33·873(5), c 10·416(2) Å, β 102·54(1)°, R 0·0363). The asymmetric unit of this compound contains three silver atoms, two nitrate anions, a bridging tridentate cyanide ion, and one and a half molecules of the bridging tetrapodal ligand 1,2,4,5-tetrakis(pyrazol-1-ylmethyl)benzene. By virtue of the bridging nature of the ligand, these units further assemble into large macrocyclic rings, with a maximum dimension of >24 Å. These rings then interlock to produce an intriguing two-dimensional metallopolymeric network.

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