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

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.

1977 ◽  
Vol 30 (11) ◽  
pp. 2465 ◽  
Author(s):  
RM Carman ◽  
CJ Hawkins ◽  
JJ Kibby

The c.d. spectra are reported for a series of benzylidene derivatives of glycerol and mannitol containing 1,3-dioxolan, 1,3-dioxan and 1,3- dioxepan ring systems. The signs of the Cotton effects of 1Lb and 1La transitions of the phenyl chromophore have been rationalized in terms of recently proposed sector rules for these transitions.


1989 ◽  
Vol 44 (11) ◽  
pp. 1464-1472 ◽  
Author(s):  
Hermann Bauer ◽  
Jeanine Brun ◽  
Alexius R. Hernanto ◽  
Wolfgang Voelter ◽  
Spyridon Paraskewas

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.


1970 ◽  
Vol 23 (9) ◽  
pp. 1735 ◽  
Author(s):  
CJ Hawkins ◽  
PJ Lawson

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.


1970 ◽  
Vol 23 (11) ◽  
pp. 2237 ◽  
Author(s):  
CJ Hawkins ◽  
CL Wong

The solution circular dichroism spectra of the 1 : 1 and 1 : 2 copper(II) complexes of a series of �-amino acids are reported for the region 12500-25000 cm-1. These spectra and spectra of the isolated 1 : 2 complexes dispersed in KBr disks have been interpreted as arising from three Cotton effects with a -,+,- sign pattern for the L configuration, except for the L-proline spectra, which were analysed in terms of a +,-,+ pattern. A tentative assignment is made for these Cotton effects, and the relative contributions of vicinal and conformational effects to the rotational strength are discussed.


2009 ◽  
Vol 58 (3) ◽  
pp. 562-565 ◽  
Author(s):  
V. I. Sokolov ◽  
V. V. Bashilov ◽  
N. V. Abramova ◽  
K. K. Babievsky ◽  
A. G. Ginzburg

1971 ◽  
Vol 24 (11) ◽  
pp. 2275 ◽  
Author(s):  
CJ Hawkins ◽  
GA Lawrance

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.


1998 ◽  
Vol 63 (8) ◽  
pp. 1187-1201 ◽  
Author(s):  
Jaroslav Zamastil ◽  
Lubomír Skála ◽  
Petr Pančoška ◽  
Oldřich Bílek

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.


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

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