Circulardichroismusuntersuchungen von Polyalkohol- und Zucker-Vanadat(V)-Komplexen / Circular Dichroism Studies of Polyalcohol and Sugar Vanadate(V) Complexes

1989 ◽  
Vol 44 (11) ◽  
pp. 1464-1472 ◽  
Author(s):  
Hermann Bauer ◽  
Jeanine Brun ◽  
Alexius R. Hernanto ◽  
Wolfgang Voelter ◽  
Spyridon Paraskewas
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Optically Active ◽  
Hydroxyl Groups ◽  
Pyranose Ring ◽  
Cotton Effects ◽  
Circular Dichroïsm

The complexes of tetravanadate ions with optically active polyols and carbohydrates with suitable steric properties show up to four separate cotton effects in the wavelength range of λ = 200-350 nm. Thus it is possible to classify pyranoses into four groups according to their circular dichroitic behaviour and determine the configuration and the conformation of the hydroxyl groups attached to the pyranose ring.

Circular dichroism spectra of amino acid complexes. II. Chelated amino acid complexes with the CoN5O chromophore

1970 ◽  
Vol 23 (9) ◽  
pp. 1735 ◽  
Author(s):  
CJ Hawkins ◽  
PJ Lawson
Keyword(s):  
Amino Acids ◽  
Circular Dichroism ◽  
Amino Acid ◽  
Visible Region ◽  
Optically Active ◽  
Circular Dichroism Spectra ◽  
Amino Acid Complexes ◽  
Similar Series ◽  
Cotton Effects ◽  
Circular Dichroïsm

The circular dichroism spectra of a series of optically active (α-aminocarboxylato)tetraamminecobalt(111) complexes have been measured in aqueous solution, and in the presence of salts of polarizable anions. The observed spectra in the visible region have been analysed to determine the signs of the Cotton effects of the three components of the 1A1g ↔ 1T1g cobalt(111) transition. For L-amino acids, the transition with A2g(D4h) parentage is negative, and the two transitions with Eg(D4h) parentage have opposite signs. Published circular dichroism spectra of complexes of the type [Co(en)2(L-am)]2+ were similarly interpreted in terms of a perturbed tetragonal chromophore, and it was shown that the vicinal effect of the L-amino acids imposed the same signs onto the component transitions as for the tetraammines and for a similar series of pentaamminecobalt(111) complexes.

Conformation of 3-acetamido-3,6-dideoxyhexopyranosides: Circular dichroism study

1979 ◽  
Vol 44 (1) ◽  
pp. 174-182 ◽  
Author(s):  
Slavomír Bystrický ◽  
Ivo Frič ◽  
Jan Staněk ◽  
Karel Čapek ◽  
Jiří Jarý ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Spatial Orientation ◽  
Amide Group ◽  
Cd Spectra ◽  
Pyranose Ring ◽  
Cotton Effects ◽  
Circular Dichroïsm

CD spectra of 15 stereoisomeric methyl 3-acetamido-3,6-dideoxyhexopyranosides were measured in methanol, 2,2,2-trifluoroethanol and acetonitrile. The data have been applied for estimation of probable conformations. The factor determining signs of the observed Cotton effects seems to be the spatial orientation of the acetamido group with respect to the pyranose ring. The possible role of a non-planar amide group is also discussed.

Optically Active Amines. Part XIII. Circular Dichroism of the N-Salicylidene Derivatives of Alkylamines

1971 ◽  
Vol 49 (17) ◽  
pp. 2902-2906 ◽  
Author(s):  
Howard E. Smith ◽  
Harry E. Ensley
Keyword(s):  
Circular Dichroism ◽  
Phenyl Group ◽  
Electron System ◽  
Optically Active ◽  
Rotational Strength ◽  
Cotton Effects ◽  
Derivatives Of ◽  
Circular Dichroïsm

Comparison of the c.d. spectra of (S)-(+)-N-salicylidene-α-phenylethylamine with those of (S)-(+)-N-salicylidene-sec-butylamine and (R)-(−)-N-salicylidene-2,2-dimethyl-3-aminobutane confirms the conclusion that the strong rotational strength shown by N-salicylidene-α- and β-phenylalkylamines is due to an interaction of the π-electron System of the phenyl group and the salicylidenimino chromophore. The sign of the Cotton effects near 255 and 315 nm shown by the N-salicylidenes of alkylamines and cycloalkylamines, when these are conformationally defined, can be correlated with their absolute configurations using a planar sector rule, similar to that used for the interpretation of the c.d. and o.r.d. spectra of N-salicylidene-α- and β-phenylalkylamines.

Circular dichroism spectra of 2-substituted propionatopentaaminocobalt(II) complexes

1971 ◽  
Vol 24 (11) ◽  
pp. 2275 ◽  
Author(s):  
CJ Hawkins ◽  
GA Lawrance
Keyword(s):  
Aqueous Solution ◽  
Circular Dichroism ◽  
Absorption Band ◽  
General Formula ◽  
Optically Active ◽  
Sign Pattern ◽  
Circular Dichroism Spectra ◽  
Cotton Effects ◽  
Circular Dichroïsm

The preparations of a series of optically active complexes with the general formula Co(NH3)5(OCOCH(X)CH3)2+ are reported for X = NH3+, OH, F, Cl, Br, C2H5, and C6H5. The circular dichroism spectra of the complexes have been measured in aqueous solution, in the presence of salts of polarizable anions, and in KBr disks. The spectra have been analysed in terms of three Cotton effects under the 1A1g → 1T1g cubic absorption band and found to be consistent with a +, -, - sign pattern for the L- isomer, corresponding to the two components of the 1A1g → 1Eg (D4h) and to the 1A1g → A2g (D4h) transition, respectively.

Ultraviolet circular dichroism studies on complexes of synthetic polynucleotides

1969 ◽  
Vol 47 (10) ◽  
pp. 977-981 ◽  
Author(s):  
Fred H. Wolfe ◽  
Kimio Oikawa ◽  
Cyril M. Kay
Keyword(s):  
Circular Dichroism ◽  
Wavelength Range ◽  
Optically Active ◽  
Electronic Transitions ◽  
Molar Ratio ◽  
Circular Dichroism Spectra ◽  
Naturally Occurring ◽  
Polyadenylic Acid ◽  
Polyuridylic Acid ◽  
Circular Dichroïsm

The ultraviolet circular dichroism spectra of complexes of polyadenylic acid and polyuridylic acid in the molar ratio of 1:1 and 1:2, and that of polyguanylic acid and polycytidilic acid have been examined over the wavelength range of 300–185 mμ. Increased resolution of spectra below 225 mμ has revealed several new ellipticity bands for these complexes which should be of considerable value in the proper counting of optically active electronic transitions and their assignment in these systems, and with naturally occurring RNA's.

New Approach to the Theory of Circular Dichroism

1998 ◽  
Vol 63 (8) ◽  
pp. 1187-1201 ◽  
Author(s):  
Jaroslav Zamastil ◽  
Lubomír Skála ◽  
Petr Pančoška ◽  
Oldřich Bílek
Keyword(s):  
Electromagnetic Wave ◽  
Circular Dichroism ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Optically Active ◽  
Semiclassical Approach ◽  
New Approach ◽  
Isotropic Media ◽  
New Formula ◽  
Circular Dichroïsm

Using the semiclassical approach for the description of the propagation of the electromagnetic waves in optically active isotropic media we derive a new formula for the circular dichroism parameter. The theory is based on the idea of the time damped electromagnetic wave interacting with the molecules of the sample. In this theory, the Lambert-Beer law need not be taken as an empirical law, however, it follows naturally from the requirement that the electromagnetic wave obeys the Maxwell equations.

First optically active ferricinium salts: A circular dichroism study

1992 ◽  
Vol 438 (3) ◽  
pp. C26-C28 ◽  
Author(s):  
Viatcheslav I. Sokolov ◽  
Irina A. Mamedyarova ◽  
Marina N. Nefedova ◽  
Günther Snatzke
Keyword(s):  
Circular Dichroism ◽  
Optically Active ◽  
Circular Dichroïsm
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