452 Mr. Gervaise Le Bas on the 



Compound. W. M.V. SA.V. A for E. 



Cyclopentane, C 5 H 10 ... 30 [97-7] 110-0 -12-3 



CH 2 — CH 2 



j CH 2 



CH 2 — CB/ 



Cyclohexane, C 6 H 12 ... 36 116*3 132-4 -16'1 D* 



^CH 2 CH 2x 



CH2 CH 2 



x ch 2 — cnf 



Cycloheptane, G 7 H M ... 42 [134*64] 154-8 -20-16 D 7 

 CH 2 ~CH 2 -CH 2n 



CH 2 

 €H 2 -CH 2 -CH/ 



Cyclooctane, C 8 H 16 ... 48 [153-67] 177-6 -24'0 D 8 



ch 2 -ch 2 -ch 2n 



CH 2 CH 2 



X CH 2 -CH-CH 2 



There is thus a distinct and regular increase in the con- 

 tractions as the number of groups in the rings increase. 

 The only ring which has not been mentioned is the three- 

 membered ring C 3 H 6 . 



A suitable hydrocarbon for the investigation of this ring 

 is Vinyl Trimethylene, 



/CHo an isomer of Isoprene, C 5 H 8 . 

 CH 2 =CH— CH I 



X CH 2 B.P.40°, d 073. 

 Calculated d BV 0*6886. 



M.V. 4|= 98-8 W18. 



Isoprene, C 5 H 8 103*6 



A for Trimethylene Ring... — 4'8 Q 



Isoprene is subject to a contraction of 0*5 foriso structure, 

 and thus the real contraction for a three-membered ring is 

 _4-8-0-5=-5*3. 



