A Theoretical Investigation of the Ring Strain Energy, Destabilization Energy, and Heat of Formation of CL-20

Table 1

Comparison of the strainless gas-phase heat of formation, destabilization energy, and gas-phase heat of formation of CL-20, ONC, and other relevant compounds of interest.

Compound	Strainless heat of formation; Δ𝑓𝐻^∘(grp.add.)𝑔 (kJ/mol)	Heat of formation; Δ𝑓𝐻^∘𝑔 (kJ/mol)	Destabilization energy or CRSE (kJ/mol)	Destabilization energy per C + N present in the ring or the cage (kJ/mol)
		55.8	117.7	39.2
Cyclopropane	−61.9	(39.3)	(101.2)	(33.7)
		(53.3)	(115.2)	(38.4)
Cyclobutane	−82.5	29.7	112.2	28.1
		(27.7)	(110.2)	(27.6)
HAIW I	325.3	306.6	−18.7	−1.6
HAIW II	325.3	301.7	−23.6	−2.0
HAIW III	325.3	323.1	−2.2	−0.2
HAIW IV	325.3	290.5	−34.8	−2.9
Isowurtzitane	−171.5	−63.5	108.0	9.0
CL-20 (HNIW I)	240.0	558.8	318.8	26.6
CL-20 (HNIW II)	240.0	554.4	314.4	26.2
CL-20 (HNIW III)	240.0	571.6	331.6	27.6
CL-20 (HNIW IV)	240.0	548.0	308.0	25.7
Cubane	−63.6	622.2	685.8	85.7
		(622.2)	685.8	85.7
Octanitrocubane	−405.0	687.5	1,092.5	136.6
		(726)	(1,131)	(141)

The values in parentheses for octanitrocubane are the heat of formation value calculated by Zhang and Xiao [8] and values calculated using this heat of formation.
Other values in parentheses are those reported in, or calculated using, those referenced in the NIST Chemistry WebBook (http://webbook.nist.gov/chemistry/) or in the CRC’s Standard Thermodynamic Properties of Chemical Substances.
HAIW refers to 2,4,6,8,10,12-hexaazaisowurtzitane.