Dynamic in situ X-ray diffraction reveals unexpected intermediate crystal structures

The compounds (H3C)2S, (H3Si)2S and (H3Ge)2S have been crystallised in situ on a diffractometer and their crystal structures determined by low-temperature X-ray diffraction. The molecules are present as monomers in the crystals. The aggregation of the molecules through secondary intermolecular contacts in the crystal is different: (H3C)2S is weakly associated into dimers by S···S contacts, whereas (H3Si)2S and (H3Ge)2S form Si···S and Ge···S contacts in an ice-analogous aggregation motif. Important geometry parameters are (H3C)2S: C-S 1.794(av) Å , C-S-C 99.2(1)°; (H3Si)2S: Si- S 2.143(1) Å , Si-S-Si 98.4°; (H3Ge)2S Ge-S 2.223(2) and 2.230(2) Å , Ge-S-Ge 98.2(1)◦.

Download Full-text

Copper Phosphonatoethanesulfonates: Temperature Dependent in Situ Energy Dispersive X-ray Diffraction Study and Influence of the pH on the Crystal Structures

Inorganic Chemistry ◽

10.1021/ic301976s ◽

2012 ◽

Vol 51 (22) ◽

pp. 12540-12547 ◽

Cited By ~ 25

Author(s):

Mark Feyand ◽

Annika Hübner ◽

André Rothkirch ◽

David S. Wragg ◽

Norbert Stock

Keyword(s):

Diffraction Study ◽

Crystal Structures ◽

Energy Dispersive ◽

X Ray Diffraction ◽

Temperature Dependent ◽

X Ray

Download Full-text

Synthesis and Structures of Simple (Silylmethyl)(methyl)ethers

Zeitschrift für Naturforschung B ◽

10.1515/znb-2003-0807 ◽

2003 ◽

Vol 58 (8) ◽

pp. 759-763 ◽

Cited By ~ 7

Author(s):

Norbert W. Mitzel

Keyword(s):

Crystal Structures ◽

Structural Parameters ◽

Structural Basis ◽

X Ray Diffraction ◽

X Ray ◽

Donor Acceptor

The compound Cl3SiCH2OCH3 was prepared by reacting ClCH2OCH3 with the Cl3SiH/NEt3 reagent. H3SiCH2OCH3 and F3SiCH2OCH3 were synthesized from Cl3SiCH2OCH3 by reduction with LiAlH4 and by fluorination with SbF3, respectively. The crystal structures of the low-melting compounds H3SiCH2OCH3 and F3SiCH2OCH3 were determined by X-ray diffraction of in situ grown crystals. Both compounds do not show any observable β -donor-acceptor interactions, but behave structurally like usual dialkylethers or silanes, as is obvious from the structural parameters in H3SiCH2OCH3 (<SiCO 108.4(3)-109.4(3)°, <COC 111.0(4)-111.6(4)°) and in F3SiCH2OCH3 (<SiCO 107.1(1), <COC 111.2(2)°). Earlier postulates of Si· · ·O interactions in compounds with SiCO units could thus not be confirmed on a structural basis.

Download Full-text

The Crystal Structures of Chlorodimethyl( dimethylamino)silane and Dimethyl-bis-(dimethylamino)silane

Zeitschrift für Naturforschung B ◽

10.1515/znb-2003-0718 ◽

2003 ◽

Vol 58 (7) ◽

pp. 708-710 ◽

Cited By ~ 2

Author(s):

Norbert W. Mitzel ◽

Krunoslav Vojinović

Keyword(s):

Single Crystals ◽

Crystal Structures ◽

Low Temperatures ◽

Structural Parameters ◽

X Ray Diffraction ◽

X Ray

Single crystals of chlorodimethyl(dimethylamino)silane, Me2NSiMe2Cl, and dimethyl-bis-(dimethylamino)silane, (Me2N)2SiMe2, have been grown in situ from the melt at low temperatures and their structures determined by X-ray diffraction. Important structural parameters (Å / °): Me2NSiMe2Cl (C2/m) Si-N 1.686(2), Si-C 1.851(1), Si- Cl 2.109(1), N-Si-Cl 111.7(1), C-Si-Cl 105.1(1), C-N-C 112.8(2), Si-N-C 123.4(1); (Me2N)2SiMe2 (P21/c) Si-N(1) 1.725(1), Si-C(1) 1.868(1), N(1)-Si-N(2) 105.7(1), C(3)- N(1)-C(4) 111.6(1), Si-N(1)-C(3) 122.4(1), Si-N(1)-C(4) 120.0(1).

Download Full-text

Coexistence of structure I and II hydrates formed from a mixture of methane and ethane gases

Canadian Journal of Physics ◽

10.1139/p03-038 ◽

2003 ◽

Vol 81 (1-2) ◽

pp. 479-484 ◽

Cited By ~ 30

Author(s):

S Takeya ◽

Y Kamata ◽

T Uchida ◽

J Nagao ◽

T Ebinuma ◽

...

Keyword(s):

Crystal Structures ◽

Gas Hydrates ◽

X Ray Diffraction ◽

Mixed Gas ◽

Growth Processes ◽

X Ray ◽

Gas Concentration ◽

In Situ Observations

X-ray diffraction measurements were conducted to determine the hydrate structures formed from a mixture of CH4 and C2H6 gases at 263 K. With increasing initial fractions of C2H6 in the gas, the crystal structures of the hydrate were structure I, structure I + structure II, structure II, structure I + structure II, and structure I. In situ observations of the growth processes of the mixed gas hydrates under constant gas concentration suggest that the coexistence of structure I and structure II hydrate were caused by occurrences of metastable hydrate structure. PACS No.: 82.75Fq

Download Full-text

Bismuth Tri- and Tetraarylcarboxylates: Crystal Structures, In Situ X-ray Diffraction, Intermediates and Luminescence

Chemistry - A European Journal ◽

10.1002/chem.201301139 ◽

2013 ◽

Vol 19 (37) ◽

pp. 12537-12546 ◽

Cited By ~ 44

Author(s):

Mark Feyand ◽

Milan Köppen ◽

Gernot Friedrichs ◽

Norbert Stock

Keyword(s):

Crystal Structures ◽

X Ray Diffraction ◽

X Ray

Download Full-text

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Download Full-text

Transmission electron microscope studies in special ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108489 ◽

1978 ◽

Vol 36 (1) ◽

pp. 268-269

Author(s):

A. Zangvil ◽

L.J. Gauckler ◽

G. Schneider ◽

M. Rühle

Keyword(s):

Phase Diagrams ◽

Crystal Structures ◽

Thin Foil ◽

Limited Extent ◽

Complex Materials ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Electron Microscopes ◽

Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

Download Full-text