The carbon–hydrogen bond strength in dimethyl ether and some properties of iodomethyl methyl ether

The kinetics and mechanism of the reaction between iodine and dimethyl ether (DME) have been studied spectrophotometrically from 515–630°K over the pressure ranges, I 2 3.8–18.9 torr and DME 39.6–592 torr in a static system. The rate‐determining step is,where k 1 is given by log ( k 1 / M −1 sec −1 ) = 11.5 ± 0.3 – 23.2 ± 0.7/θ, with θ = 2.303 RT in kcal/mole. The ratio k 2 / k −1 ,is given by log ( k 2 / k −1 ) = −0.05 ± 0.19 + (0.9 ± 0.45)/θ, whence the carbon‐hydrogen bond dissociation energy, DH ° (HCH 2 OCH 3 ) = 93.3 ± 1 kcal/mole. From this, Δ H ° f (CH 2 OCH 3 ) = −2.8 kcal and DH °(CH 3 OCH 2 ) = 9.1 kcal/mole. Some nmr and uv spectral features of iodomethyl ether are reported.