X-ray structure and properties of a cyclo[6]pyrrole[3]thiophene

A new member of the cyclo[n]pyrrole class of expanded porphyrins was prepared from the corresponding thiophene-containing terpyrrole precursor through use of a mild electrochemical oxidative procedure. The isolated macrocycle, featuring nine heterocyclic subunits directly connected through their α,α′-positions, is the largest cyclo[n]pyrrole derivative reported to date. The structure obtained via synchrotron radiation-based studies revealed a dimeric arrangement involving individual macrocyclic subunits.

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Graded X-ray Optics for Synchrotron Radiation Applications

Journal of Synchrotron Radiation ◽

10.1107/s0909049597019043 ◽

1998 ◽

Vol 5 (3) ◽

pp. 239-245 ◽

Cited By ~ 9

Author(s):

A. Erko ◽

M. Veldkamp ◽

W. Gudat ◽

N. V. Abrosimov ◽

S. N. Rossolenko ◽

...

Keyword(s):

Synchrotron Radiation ◽

Magnetron Sputtering ◽

Single Crystals ◽

Theoretical Data ◽

Lattice Parameter ◽

Structure And Properties ◽

Czochralski Technique ◽

Spectral Measurements ◽

Optical Elements ◽

X Ray

Using X-ray diffractometry and spectral measurements, the structure and properties of graded X-ray optical elements have been examined. Experimental and theoretical data on X-ray supermirrors, which were prepared by the magnetron sputtering technique using precise thickness control, are reported. Measurements on graded aperiodic Si1−x Ge x single crystals, which were grown by the Czochralski technique, are also presented. The lattice parameter of such a crystal changes almost linearly with increasing Ge concentration. The measurements indicate that Si1−x Ge x crystals with concentrations up to 7 at.% Ge can be grown with a quality comparable to that of pure Si crystals.

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Direct Observation of Monolayer Zones in Al-wt 4% Cu

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178823 ◽

1990 ◽

Vol 48 (1) ◽

pp. 14-15

Author(s):

B. Jouffrey ◽

D. Dorignac ◽

A. Bourret

Keyword(s):

Solid Solution ◽

Synchrotron Radiation ◽

Direct Observation ◽

Supersaturated Solid Solution ◽

Original Model ◽

X Ray ◽

Image Position

Since the early works on GP zones and the model independently proposed by Preston and Guinier on the first steps of precipitation in supersaturated solid solution of aluminium containing a few percent of copper, many works have been performed to understand the structure of different stages in the sequence of precipitation.The scheme which is generally admitted can be drawn from a work by Phillips.In their original model Guinier and Preston analysed a GP zone as composed of a single (100) copperrich plane surrounded by aluminum atomic planes with a slightly shorter distance from the original plane than in the solid solution.From X-ray measurements it has also been shown that GP1 zones were not only copper monolayer zones. They could be up to a few atomic planes thick. Different models were proposed by Guinier, Gerold, Toman. Using synchrotron radiation, proposals have been recently made.

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