﻿Organic Substances and the Electron Theory. 203 



IX. Two rings united by one or more methylene groups (the 

 effect is apparently just felt through two] . 



The frequency equation is 



A±0A' = O, (xvi.) 



e.g. diphenyl methane 18 , dibenzyl. 



When the rings are united directly, as in diphenyl, the 

 approximation required for the above does not hold. It will 

 be noticed that the yS and 7 bands will be found in the above 

 cases (VI.), (VII.), (VIII.), and (IX.). 



It is easy to see that (xv.) is related to (xvi.) in the same 

 way as (xiii.) to the benzene equation, A = (xi.). 



The following values of the constants may be quoted as 

 giving numerical results agreeing closely with the observed 

 values : — 



Values of c. 

 Carbon, -CH 2 '297, -CHMe '278, -CMe 2 -252. 



-CMeEt -247, -CEt 2 -241. 



Oxygen, hydroxy lie, '60. 

 ketonic, *20. 



[In the lower aldehydes the stability constant is much 

 smaller, as can be seen from the position of the bands. 

 This is especially marked in formaldehyde, and is in accord 

 with the chemical nature of these substances.] 



Nitrogen, — NH 2 -17 (assuming 1=1, i. e. 1 electron free). 



-JS T Me 2 :15. 



= N *12 in azo derivatives. 

 Iodine, I -16. 



Values of m. 



C to C, *13 if adjacent. 



'02 if separated by one carbon atom. 

 (J to in ketones, *48. 

 C to OH (in benzene derivatives), 1*49 (r). 



to =N azo „ ,, -57 if adjacent. 



*07 if separated by one 

 — to N (amido) , '543. atom. 



=N to =N, -38. ^ 



(in azo derivatives), 



1 to I att. to same carbon, *38. 

 to adjacent carbons, '04. 



In benzene m = '275^ assuming m m and m p almost equal, 

 m =='004 > There are only two equations to 

 m" 1 =*056 3 calculate the three unknowns. 



