
TY  - JOUR
A1  - Beecham, AF 
A1  - Fock, W 
A1  - Mathieson, AM 
T1  - The relationship of &#949;<sub>L</sub> and &#949;<sub>R</sub> from consideration of bisignate C.D. curves of &#945;,&#946;-unsaturated ketones
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1984
VL  - 37
IS  - 4
SP  - 667
EP  - 677
KW  - 
UR  - https://doi.org/10.1071/CH9840667 
N2  - From reconsideration of experimental evidence of &#8710;&#949; and &#949; curves and extrapolation of comments by Beecham and Collins1 it is concluded that the occurrence of bisignate n- &#960;* c.d. curves for ketones and &#945;,&#946;-unsaturated ketones does not require hypothesizing the existence of two spectral bands of opposite sign and therefore indicates that the relationship between &#949;L and &#949;R for a single transition does not necessarily involve a simple constant amplitude factor as the conventional interpretation holds. An alternative interpretation of bisignate curves is proposed, based on one spectral band, the relationship between &#949;L and &#949;R involving differential half-widths of the vibronic components of the L series relative to the R series and a variable relative-amplitude scale along the vibronic progression. If appropriate scale and differential half-width parameters are used, the characteristics of monosignate and bisignate curves can be demonstrated by means of synthetic curves. 
ER  -

