Metal-assisted reactions. Part 29. Structure and hydrogenolysis of C–N bonds in derivatives of aromatic amines. Bond length and electronegativity changes from X-ray crystallographic data

Author(s):  
Amadeu, F. Brigas ◽  
William Clegg ◽  
Christopher J. Dillon ◽  
Custodia F. C. Fonseca ◽  
Robert A. W. Johnstone
ChemInform ◽  
2010 ◽  
Vol 32 (45) ◽  
pp. no-no
Author(s):  
Amadeu F. Brigas ◽  
William Clegg ◽  
Christopher J. Dillon ◽  
Custodia F. C. Fonseca ◽  
Robert A. W. Johnstone

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Felix Lederle ◽  
Eike G. Hübner

Abstract3D models of chemical structures are an important tool for chemistry lectures and exercises. Usually, simplified models based on standard bond length and angles are used. These models allow for a visualized discussion of (stereo)chemical aspects, but they do not represent the true spatial conditions. 3D-printing technologies facilitate the production of scale models. Several protocols describe the process from X-ray structures, calculated geometries or virtual molecules to printable files. In contrast, only a few examples describe the integration of scaled models in lecture courses. True bond angles and scaled bond lengths allow for a detailed discussion of the geometry and parameters derived therefrom, for example double bond character, aromaticity and many more. Here, we report a complete organic chemistry/stereochemistry lecture course and exercise based on a set of 37 scale models made from poly(lactic acid) as sustainable material. All models have been derived from X-ray structures and quantum chemical calculations. Consequently, the models reflect the true structure as close as possible. A fixed scaling factor of 1 : 1.8·108 has been applied to all models. Hands-on measuring of bond angles and bond length leads to an interactive course. The course has been evaluated with a very positive feedback.


2021 ◽  
Vol 7 (8) ◽  
pp. 110
Author(s):  
Songjie Yang ◽  
Matteo Zecchini ◽  
Andrew Brooks ◽  
Sara Krivickas ◽  
Desiree Dalligos ◽  
...  

The syntheses of new BEDT-TTF derivatives are described. These comprise BEDT-TTF with one ethynyl group (HC≡C-), with two (n-heptyl) or four (n-butyl) alkyl side chains, with two trans acetal (-CH(OMe)2) groups, with two trans aminomethyl (-CH2NH2) groups, and with an iminodiacetate (-CH2N(CH2CO2−)2 side chain. Three transition metal salts have been prepared from the latter donor, and their magnetic properties are reported. Three tris-donor systems are reported bearing three BEDT-TTF derivatives with ester links to a core derived from benzene-1,3,5-tricarboxylic acid. The stereochemistry and molecular structure of the donors are discussed. X-ray crystal structures of two BEDT-TTF donors are reported: one with two CH(OMe)2 groups and with one a -CH2N(CH2CO2Me)2 side chain.


1984 ◽  
Vol 259 (20) ◽  
pp. 12714-12717
Author(s):  
M A Navia ◽  
J P Springer ◽  
M Poe ◽  
J Boger ◽  
K Hoogsteen

1985 ◽  
Vol 21 (1) ◽  
pp. 65-70 ◽  
Author(s):  
P. Corradini ◽  
R. Napolitano ◽  
V. Petraccone ◽  
B. Pirozzi ◽  
A. Tuzi

2003 ◽  
Vol 68 (6) ◽  
pp. 2528-2528
Author(s):  
Pai-Chi Li ◽  
Tsung-Shing Wang ◽  
Gen-Hsian Lee ◽  
Yi-Hong Liu ◽  
Yu Wang ◽  
...  

2010 ◽  
Vol 25 (3) ◽  
pp. 247-252 ◽  
Author(s):  
F. Laufek ◽  
J. Návrátil

The crystal structure of skutterudite-related phase IrGe1.5Se1.5 has been refined by the Rietveld method from laboratory X-ray powder diffraction data. Refined crystallographic data for IrGe1.5Se1.5 are a=12.0890(2) Å, c=14.8796(3) Å, V=1883.23(6) Å3, space group R3 (No. 148), Z=24, and Dc=8.87 g/cm3. Its crystal structure can be derived from the ideal skutterudite structure (CoAs3), where Se and Ge atoms are ordered in layers perpendicular to the [111] direction of the original skutterudite cell. Weak distortions of the anion and cation sublattices were also observed.


2005 ◽  
Vol 58 (7) ◽  
pp. 531
Author(s):  
Laura Andrau ◽  
Jonathan M. White

Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C–OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6.


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