VIII, A, 1 



Pratt and Gibbs: Absorption Spectra 



53 



azophenine the isorropesis occurring between the two unsatu- 

 rated nitrogen atoms in the para position produces the same 

 effect as the carbonyl groups. Since the absorption bands are 

 well developed and in much the same positions when phenol is 

 employed as the solvent, it is evident that the absence of a well- 

 marked phenoquinone band in this portion of the spectrum is 

 not to be attributed to this solvent. 



The dilution at which the band characteristic of the quinoid 

 structure makes its appearance is dependent upon the nature of 

 the adjacent groups, since this band is shown in tenth molar 

 solutions of quinone and in thousandth or ten-thousandth molar 

 solutions of the other compounds mentioned. The argument 

 employed by Baly, Tuck, and Marsden 6 that the bands of the 



Oscillation frequency (— ). 



A 



2000 22 24 26 28 3000 32 34 36 38 4000 42 44 46 



4.4 

 4.2 

 4.0 

 3.8 

 3.6 

 3.4 

 3.2 

 3.0 

 2.8 

 2.6 

 2.4. 

 2.2 

 2.0 

 1.8 

 1.6 

 1.4 

 1.2 





v\ 































v^ 









\Qt 



lino' 



e 





















K 





























\ 



l 



























M \ 





























■ 

 6 p 



10 l > 



heno 



l\. 















































I 



i 



t 





























r 

 / 

 1 































I 

 i 



i 





























i 

 / 































/ 

 i 

 I 















Pher 

 in 



oouinon 



phenol 



> 





1 

 H 







i 

 i 



i 







Phet 



ol 



















\ 



V. / 





































































\ 

 1 



\ 

 \ 

























M '"\ 







\ 

 \ 

 \ 

 \ 

















li 



M 



-f-\ 



1, 



)0(A 









'» 















* 



ohen 



»/ 















1.000 u 



s 



100 « 



Fig. 1. — Full curves = phenoquinone. 



The upper in alcohol, the middle in alcohol with 8 equiv- 

 alents of phenol, and the lower in pure phenol. 

 Dot curve = quinone in alcohol. 

 Dash curve := phenol in alcohol. 



'Journ. Chem. Soc. London (1910), 97, 588. 



