Lead(II) and barium(II) complexes of a potentially octadentate macrocyclic ligand (H4L), capable of providing endogenous alkoxy and phenoxy bridges. The X-ray crystal structures of [Pb(H4L)][ClO4]2, [Pb2(H2L)][ClO4]2, and [(H6L)(H2O)2][ClO4]2

1989 ◽  
pp. 19 ◽  
Author(s):  
Santokh S. Tandon ◽  
Vickie McKee
Keyword(s):  
Crystal Structures ◽  
Macrocyclic Ligand ◽  
X Ray

Metal Complexes with a New Tetrapyridyl Pendant Armed Macrocyclic Ligand. X-ray Crystal Structures of CuII and NiII Complexes

2003 ◽  
Vol 629 (2) ◽  
pp. 268-274 ◽  
Author(s):  
Laura Valencia ◽  
Rufina Bastida ◽  
Montserrat López-Deber ◽  
Alejandro Macías ◽  
Adolfo Rodríguez ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Crystal Structures ◽  
Macrocyclic Ligand ◽  
X Ray

Two Metal Complexes of the Macrocyclic Ligand 1,4,7-Triazacyclodecane (tacd). Crystal Structures of [Zn(tacd)2](ClO4)2 and [Cu(tacd)2]Br2.4H2O

1995 ◽  
Vol 48 (1) ◽  
pp. 139 ◽  
Author(s):  
XM Chen ◽  
YX Yao ◽  
KL Shi ◽  
TCW Mak
Keyword(s):  
Metal Complexes ◽  
Crystal Structures ◽  
Macrocyclic Ligand ◽  
Octahedral Coordination ◽  
Coordination Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Distorted Octahedral

Two metal complexes of 1,4,7-triazacyclodecane ( tacd ), [Zn( tacd )2] (ClO4)2 (1) and [Cu( tacd )2] Br2.4H2O (2), have been prepared and characterized by X-ray crystallography. Crystals of (1) are monoclinic, P21/n, a 9.506(2), b 10.279(3), c 11.505(2) Ǻ, β 91.29(2)°; crystals of (2) are orthorhombic, Pbca, a 12.035(3), b 13.673(3), c 14.248(2) Ǻ. The zinc(II) atom in (1) is surrounded in a distorted octahedral N6 environment with Zn-N bonds at 2.121(5)-2.131(4) Ǻ; the copper(II) atom in (2) adopts an elongated octahedral coordination geometry with the Cu-N bonds at 2.066(4)-2.294(5) Ǻ.

Transmission electron microscope studies in special ceramics

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.

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