Darstellung, Schwingungsspektren und Normalkoordinatenanalyse von Chloro-Bromo-Rhodaten(III) / Preparation, Vibration Spectra and Normal Coordinate Analysis of Chloro-Bromo-Rhodates(III)

1989 ◽  
Vol 44 (10) ◽  
pp. 1221-1227 ◽  
Author(s):  
W. Preetz ◽  
W. Kuhr
Keyword(s):  
Exchange Chromatography ◽  
Trans Isomers ◽  
Normal Coordinate ◽  
Valence Force ◽  
Trans Influence ◽  
Diethylaminoethyl Cellulose ◽  
Point Groups ◽  
First Time ◽  
Ir And Raman ◽  
Good Agreement

The mixed chloro-bromo-rhodates(III) [RhClnBr6-n]3-, n = 1-5, have been separated for the first time by ion exchange chromatography on diethylaminoethyl-cellulose. Due to the stronger trans-effect of Br, as compared with Cl, on treatment of [RhBr6]3- with conc. HCl nearly pure cis/fac-isomers for n = 2, 3, 4 are formed. The reaction of [RhCl6]3- with conc. HBr yields mixtures of the cis/trans-isomers for n = 2, 4, which cannot be separated, but mer-[RhCl3Br3]3 is formed stereospecifically. The IR and Raman spectra of all isolated mixed ligand complexes are completely assigned according to point groups Oh, D3d, C4v, C3v and C2v, supported by normal coordinate analyses based on a general valence force field. The good agreement of calculated and observed frequencies confirms the assignments. Due to the stronger trans-influence of Br as compared to Cl, in all asymmetric Cl—Rh—Br axes the Rh—Br bonds are strengthened and the Rh—Cl bonds are weakened, indicated by valence force constants for Rh—Br approximately 14% higher, for Rh—Cl 10% lower, as compared with the values calculated for symmetric Br—Rh—Br and Cl—Rh—Cl axes, respectively.

Teaching Molecular Symmetry of Dihedral Point Groups by Drawing Useful 2D Projections

2015 ◽  
Vol 92 (8) ◽  
pp. 1422-1425 ◽  
Author(s):  
Lan Chen ◽  
Hongwei Sun ◽  
Chengming Lai
Keyword(s):  
Molecular Symmetry ◽  
Point Groups

Fullerenes C20-C60: Combinatorial types and symmetry point groups

2002 ◽  
Vol 47 (5) ◽  
pp. 720-722 ◽  
Author(s):  
Yu. L. Voytekhovsky ◽  
D. G. Stepenshchikov
Keyword(s):  
Symmetry Point ◽  
Point Groups

Point groups and crystal classes

2016 ◽  
pp. 720-776
Author(s):  
Th. Hahn ◽  
H. Klapper ◽  
U. Müller ◽  
M. I. Aroyo
Keyword(s):  
Point Groups

scholarly journals 3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups

2014 ◽  
Vol 91 (8) ◽  
pp. 1174-1180 ◽  
Author(s):  
Vincent F. Scalfani ◽  
Thomas P. Vaid
Keyword(s):  
Solid Models ◽  
3D Printed ◽  
Point Groups
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