The Homogeneous Unimolecular Decomposition of Gaseous Alkyl Nitrites III. The Decomposition of n-Propyl Nitrite

The thermal decomposition of n‐propyl nitrite is a homogeneous first order reaction in the temperature range 170 to 210°C. The mechanism of the decomposition is analogous to those of the other alkyl nitrites, viz., $${\mathrm{C}}_3{\mathrm{H}}_7\mathrm{ONO}\to \mathrm{NO}+\frac{1}{2}{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{CHO}+\frac{1}{2}{\mathrm{C}}_3{\mathrm{H}}_7\mathrm{OH}.$$ The rate of reaction is given by $${\text{K=2.75×10}}^{14}{e}^{\text{−37650/RT ·}}\sec {.}^{\text{−1}}.$$ The rates and activation energies of the various nitrite decompositions are compared. It is concluded that the increase in rate with the higher members of the homologous series is probably due to the participation of extra vibrational degrees of freedom. An estimate of the strength of the —O–N— bond is made.