Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Relative enthalpies of isomers - Comparison of 298.15K enthalpies (kJ mol^-1)

Isomers of C₅H₈

index	Species	CAS number	Name	Relative experimental enthalpy (kJ mol-1)	sketch
a	C5H8	311751	Bicyclo[1.1.1]pentane
b	CH3CCCH2CH3	627214	2-Pentyne
c	C5H8	142290	Cyclopentene	0.0
d	C5H8	78795	1,3-Butadiene, 2-methyl-	41.8
e	C5H8	2004708	1,3-Pentadiene, (E)-	41.9
f	C5H8	1574410	1,3-Pentadiene, (Z)-	48.9
g	C5H8	591935	1,4-Pentadiene	71.8
h	C5H8	1120565	Cyclobutane, methylene-	87.6
i	C5H8	598254	1,2-Butadiene, 3-methyl-	95.2
j	C5H8	693867	Ethenylcyclopropane	97.3
k	C5H8	591968	2,3-Pentadiene	99.2
l	C5H8	591957	1,2-Pentadiene	106.8
m	C5H8	627190	1-pentyne	110.4
n	C5H8	185944	Bicyclo[2.1.0]pentane	123.8
o	C5H8	157404	Spiropentane	151.3