Structure and stereochemistry in 'f-block' complexes of high coordination number. VI. Crystallographic characterizations of Bis[(1 ,1-dimethyl-3-oxobutyl)triphenyl-phosphonium] hexabromouranate(IV) and Tetrabromobis[ethane-1,2-diylbis(diphenylarsine) oxide]uranium(IV)

1983 ◽  
Vol 36 (3) ◽  
pp. 469 ◽  
Author(s):  
DL Kepert ◽  
JM Patrick ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Coordination Number ◽  
Structure Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Coordination Number ◽  
Triphenyl Phosphonium ◽  
Diffraction Structure ◽  
Centrosymmetric Molecule ◽  
High Coordination

Complexes obtained by the reaction of uranium pentabromide with triphenylphosphine and with ethane-1,2-diylbis(diphenylarsine) (Ph2AsCH2CH2AsPh2) have been characterized by single-crystal X-ray diffraction structure determination at 295 K and shown to be [Ph3PCMe2CH2C(O)Me]2- [Ubr6](1) and [Ubr4(Ph2As(O)CH2CH2AsPh2)2] (2). Crystals of (1) are orthorhombic, Pbca, a 20.46(1), b 16.033(8), c 15.663(10) �, Z 4, the structure being refined to a residual of 0.07 for 990 independent reflections; in the centrosymmetric anion, U-Br distances range from 2.750(5) to 2.803(5) �. Crystals of (2) are monoclinic, P21/c, a 12.64(1), b 10.870(6), c 20.81(2) �, 110.88(2)�, Z 2, the structure being refined to a residual of 0.05 for 1531 independent reflections. In the centrosymmetric molecule, U-Br distances are 2.806(4) and 2.811(4) �; the diarsine oxide ligand is unidentate, coordinated through the oxygen rather than the arsenic with U-O 2.19(1) �.

Neutron and X-ray single-crystal diffraction from protein microcrystalsviamagnetically oriented microcrystal arrays in gels

2016 ◽  
Vol 72 (7) ◽  
pp. 823-829 ◽  
Author(s):  
Shu Tsukui ◽  
Fumiko Kimura ◽  
Katsuhiro Kusaka ◽  
Seiki Baba ◽  
Nobuhiro Mizuno ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Structure Determination ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Diffraction Structure ◽  
First Time ◽  
Magnetically Aligned

Protein microcrystals magnetically aligned in D2O hydrogels were subjected to neutron diffraction measurements, and reflections were observed for the first time to a resolution of 3.4 Å from lysozyme microcrystals (∼10 × 10 × 50 µm). This result demonstrated the possibility that magnetically oriented microcrystals consolidated in D2O gels may provide a promising means to obtain single-crystal neutron diffraction from proteins that do not crystallize at the sizes required for neutron diffraction structure determination. In addition, lysozyme microcrystals aligned in H2O hydrogels allowed structure determination at a resolution of 1.76 Å at room temperature by X-ray diffraction. The use of gels has advantages since the microcrystals are measured under hydrated conditions.

scholarly journals Balancing Bulkiness in Gold(I) Phosphino-Triazole Catalysis

2019 ◽  
Author(s):  
Yiming Zhao ◽  
Matthew Wakeling ◽  
Fernanda Meloni ◽  
Tze Jing Sum ◽  
Huy van Nguyen ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Phosphorus Atom ◽  
X Ray Diffraction ◽  
Chloride Complexes ◽  
X Ray ◽  
Diffraction Structure

A series of phosphino triazoles are disclosed, within which, the phosphorus atom is appended by one, two or three triazole motifs. Gold(I) chloride complexes of the synthesised ligands were prepared and analysed by techniques including single crystal X-ray diffraction structure determination. <i>SambVca</i> (2.0) was used to determine percentage buried volumes. The effectiveness of these gold(I) chloride complexes to serve as precatalysts for alkyne hydration were assessed.<br>

The Deoxygenation of Some Carbohydrate Diols Via the Derived Cyclic Thiocarbonate

1986 ◽  
Vol 39 (4) ◽  
pp. 699 ◽  
Author(s):  
JJ Patroni ◽  
RV Stick ◽  
LM Engelhardt ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Methyl Iodide ◽  
Structure Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tributyltin Hydride ◽  
Diffraction Structure

The treatment of methyl 2,6-di-O-methyl-3,4-O-thiocarbonyl-β-D-galactoside with methyl iodide gives mainly the 3-deoxy-3-iodo-D-guloside , whereas the α- anomer of the above and methyl 2-O-methyl-3,4- O- thiocarbonyl-β-L-arabinoside give mainly the 4-deoxy-4-iodo-D- glycosides. An explanation is given for these and some previously reported results. As well, two of the above cyclic thiocarbonates (β-D-galacto and β-L- arabino), together with two cyclic thiocarbonates derived from methyl α-D- mannopyranoside, when treated with tributyltin hydride, gave mixtures (nearly 1:1) of products resulting from deoxygenation . Single-crystal X-ray diffraction structure determination of the β-D- galacto and the β-L- arabino cyclic thiocarbonates showed both pyranose rings to be in the 4C1 conformation.

scholarly journals Balancing Bulkiness in Gold(I) Phosphino-Triazole Catalysis

2019 ◽  
Author(s):  
Yiming Zhao ◽  
Matthew Wakeling ◽  
Fernanda Meloni ◽  
Tze Jing Sum ◽  
Huy van Nguyen ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Phosphorus Atom ◽  
X Ray Diffraction ◽  
Chloride Complexes ◽  
X Ray ◽  
Diffraction Structure

A series of phosphino triazoles are disclosed, within which, the phosphorus atom is appended by one, two or three triazole motifs. Gold(I) chloride complexes of the synthesised ligands were prepared and analysed by techniques including single crystal X-ray diffraction structure determination. <i>SambVca</i> (2.0) was used to determine percentage buried volumes. The effectiveness of these gold(I) chloride complexes to serve as precatalysts for alkyne hydration were assessed.<br>

The Synthesis of Some Compounds Containing the Selenocarbonyl Group by Using Viehe's Salt/Sodium Hydrogen Selenide: an Approach to Cyclic Selenocarbonates in the Monosaccharide Series

1988 ◽  
Vol 41 (4) ◽  
pp. 549 ◽  
Author(s):  
CM Copeland ◽  
J Ghosh ◽  
DP McAdam ◽  
BW Skelton ◽  
RV Stick ◽  
...  
Keyword(s):  
Single Crystal ◽  
Methyl Iodide ◽  
Structure Determination ◽  
X Ray Diffraction ◽  
Hydrogen Selenide ◽  
X Ray ◽  
Sodium Hydrogen ◽  
Diffraction Structure ◽  
Vicinal Diols

The treatment of various thiols, phenols and amines with Viehe's salt (Me2N+=CCl2 Cl -), followed by addition to sodium hydrogen selenide in ethanol, can lead to useful syntheses of compounds containing the selenocarbonyl group, namely selenothiocarbamates, selenodithiocarbonates, selenothiocarbonates and selenoureas . As well, the combination of Viehe's salt/sodium hydrogen selenide allows the conversion of some carbohydrate cis vicinal diols into novel cyclic selenocarbonates, and a single-crystal X-ray diffraction structure determination of one of these selenocarbonates is reported. The treatment of these selenocarbonates with methyl iodide and various phosphorus reagents is reported, as well as some unsuccessful attempts towards tellurocarbonates and telluroureas.

The Selective Monobenzylidenation of Some Monosaccharides and Their Derivatives With α,α-Dimethoxytoluene

1988 ◽  
Vol 41 (1) ◽  
pp. 91 ◽  
Author(s):  
JJ Patroni ◽  
RV Stick ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Acid Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure

The treatment of some monosaccharides and their derivatives with a,a-dimethoxytoluene and an acid catalyst in dimethylformamide at about 80° can lead to selective benzylidenation , e.g. methyl a-D- mannopyranoside gives mainly methyl 4,6-Obenzylidene-a-D-mannoside, together with two other minor monobenzylidene derivatives (2,3-) and two minor dibenzylidene derivatives (2,3:4,6-). The treatment of various other pyranoses and pyranosides is also described. As well, a 1H n.m.r . study of the acid transformation of some of the above α-D- mannosides is reported, together with a single-crystal X-ray diffraction structure determination of a novel monobenzylidene derivative, namely methyl (S)- 2,3-O-benzylidene-α-D-mannopyranoside.

Molecular tapes in the structure of isoguaninium chloride

2017 ◽  
Vol 74 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Urszula Anna Budniak ◽  
Paulina Maria Dominiak
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Charge Density ◽  
Interaction Energy ◽  
Electrostatic Interaction ◽  
Electrostatic Interactions ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure

Isoguanine, an analogue of guanine, is of intrinsic interest as a noncanonical nucleobase. The crystal structure of isoguaninium chloride (systematic name: 6-amino-2-oxo-1H,7H-purin-3-ium chloride), C5H6N5O+·Cl−, has been determined by single-crystal X-ray diffraction. Structure analysis was supported by electrostatic interaction energy (E es) calculations based on charge density reconstructed with the UBDB databank. In the structure, two kinds of molecular tapes are observed, one parallel to (010) and the other parallel to (50\overline{4}). The tapes are formed by dimers of isoguaninium cations interacting with chloride anions. E es analysis indicates that cations in one kind of tape are oriented so as to minimize repulsive electrostatic interactions.

scholarly journals Intermetallic REPtZn Compounds with TiNiSi-type Structure

2011 ◽  
Vol 66 (7) ◽  
pp. 671-676 ◽  
Author(s):  
Trinath Mishra ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Coordination Number ◽  
High Frequency ◽  
Three Dimensional ◽  
Type Structure ◽  
Rare Earth Compounds ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray

The equiatomic rare earth compounds REPtZn (RE = Y, Pr, Nd, Gd-Tm) were synthesized from the elements in sealed tantalum tubes by high-frequency melting at 1500 K followed by annealing at 1120 K and quenching. The samples were characterized by powder X-ray diffraction. The structures of four crystals were refined from single-crystal diffractometer data: TiNiSi type, Pnma, a = 707.1(1), b = 430.0(1), c = 812.4(1) pm, wR2 = 0.066, 602 F2, 21 variables for PrPt1.056Zn0.944; a = 695.2(1), b = 419.9(1), c = 804.8(1) pm, wR2 = 0.041, 522 F2, 21 variables for GdPt0.941Zn1.059; a = 688.2(1), b = 408.1(1), c = 812.5(1) pm, wR2 = 0.041, 497 F2, 22 variables for HoPt1.055Zn0.945; a = 686.9(1), b = 407.8(1), c = 810.4(1) pm, wR2 = 0.061, 779 F2, 20 variables for ErPtZn. The single-crystal data indicate small homogeneity ranges REPt1±xZn1±x. The platinum and zinc atoms build up three-dimensional [PtZn] networks (265 - 269 pm Pt-Zn in ErPtZn) in which the erbium atoms fill cages with coordination number 16 (6 Pt + 6 Zn + 4 Er). Bonding of the erbium atoms to the [PtZn] network proceeds via shorter RE-Pt distances, i. e. 288 - 293 pm in ErPtZn.

Single-crystal Data of Ternary Germanides RE2Nb3Ge4 (RE = Sc, Y, Gd–Er, Lu) and Sc2Ta3Ge4 with Ordered Sm5Ge4-type Structure

2013 ◽  
Vol 68 (5-6) ◽  
pp. 625-634 ◽  
Author(s):  
Bastian Reker ◽  
Samir F. Matar ◽  
Ute Ch. Rodewald ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Coordination Number ◽  
Electronic Structure Calculations ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
Structure Calculations ◽  
The Rare Earth

Small single crystals of the Sm5Ge4-type (space group Pnma) germanides RE2Nb3Ge4 (RE = Sc, Y, Gd-Er, Lu) and Sc2Ta3Ge4 were synthesized by arc-melting of the respective elements. The samples were characterized by powder and single-crystal X-ray diffraction. In all structures, except for Sc2.04Nb2.96Ge4 and Sc2.19Ta2.81Ge4, the rare earth and niobium atoms show full ordering on the three crystallographically independent samarium sites of the Sm5Ge4 type. Two sites with coordination number 6 are occupied by niobium, while the slightly larger site with coordination number 7 is filled with the rare earth element. Small homogeneity ranges with RE=Nb and RE=Ta mixing can be expected for all compounds. The ordered substitution of two rare earth sites by niobium or tantalum has drastic effects on the coordination number and chemical bonding. This was studied for the pair Y5Ge4/Y2Nb3Ge4. Electronic structure calculations show larger charge transfer from yttrium to germanium for Y5Ge4, contrary to Y2Nb3Ge4 which shows stronger covalent bonding due to the presence of Nb replacing Y at two sites

Structure and stereochemistry in 'f-block' complexes of high coordination number. VII. The [M(unidentate X)2(unidentate Y)6] system: Crystal structure of hexaaquadichloroeuropium(III) chloride (a redetermination)

1983 ◽  
Vol 36 (3) ◽  
pp. 477 ◽  
Author(s):  
DL Kepert ◽  
JM Patrick ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Coordination Number ◽  
Title Compound ◽  
Chlorine Atoms ◽  
Coordination Environment ◽  
Twofold Axis ◽  
High Coordination Number ◽  
Europium Atom ◽  
High Coordination

The crystal structure of the title compound [EuCl2(OH2)2]Cl ('europium trichloride hexahydrate') has been redetermined from single-crystal diffractometer data at 295 K and refined to a residual of 0.040 for 1094 independent 'observed' reflections. Crystals are monoclinic, P2/n, a 9.659(3), b 6.529(2), c 7.936(4) �, β 93.67(4)�, Z 2. The europium atom lies on a crystallographic twofold axis, which passes between the two planes of a square-antiprismatic coordination environment in which the two chlorine atoms, on opposite faces, lie cis to each other. Eu-O distances range from 2.401(6) to 2.431(5) �; Eu-Cl is 2.774(2) �.

Sign in / Sign up

Export Citation Format

Share Document