The rate of decomposition of ethyl nitrite (EN) has been studied in a static system over the temperature range of 162-218°C. The main products are formaldehyde, acetaldehyde, ethanol, and nitrous oxide. For low concentrations of EX (10-5-10-4M), but with a high total pressure of CF, (-0.9 atm) and small extents of reaction (2-60/,), the first-order homogeneous rates of CHZO formation are a direct measure of reaction (l), since k3b >> k z ( X O ) :Addition of large amounts of NO(m0.9 atm) completely suppressed CH20 formation in agreement with the observed value for k3a.Since (El + R?') and AH"1 are identical, both may be equated with D(Et0 -NO) = 42.4 =k 0.9 kcal/mol and E2 = 0 f 1 kcal/mol. The thermochemistry leads to the result AH",(EN) = -24.5 f 1 kcal/mol.From AS"1 and AX, k2 is calculated to be 10i0.3M-1 . s-'. From an independent observation that ks/kz = 0.3 f 0.05 independent of temperature it is concluded that ks = 10g-*M-' -s-l.Although the yields of AcH are affected by the surface-to-volume ratio of different reaction vessels, it is concluded that in a spherical reaction vessel, the AcH arises as the result of an essentially homogeneous elimination of HNO from EN(5):The rate of reaction (1) is given by kl = 10i6.0-41.8/8 s-l.EtO + NO -% AcH + HNO The addition of NO has no effect on the AcH yields. E N A AcH + HNO and reaction (6). isobutane (t-BuH) as a radical trap for EtO (4),The rate of AcH formation is given by kobr = 1013.7-37.5/8 s-l. By using EtO + t-BuH A EA + (1-Bu) a value for k3a was determined to be 1016.0-*1,6/8 5-1.From an independent observation that kz:kp: kg:k6, was 1: 0.4: 0.3: 0.18 EtONOl+ EtO + NOz EtO + NOz -% AcH + HONO we find kz. = 109.9M-1 . 8-1, kl, = 1016.0-40.0/@ s-1, and ks, = 109.6M-1. 8-1.

The heats of formation of Cs and C, alkyl nitrites (RONO) have been determined via their heats of combustion by bomb calorimetry, thereby providing a complete set of values of AH'/ for CI-C, alkyl nitrites. The experimental values are in excellent agreement with values derived from group additivity rules. For branched compounds these calculations involve corrections for gauche interactions. In these cases, the gauche interactions are reflected in the activation energies El determined by recent kinetic studies, required for breaking the RO-NO bond.The hcats of formation of the alkoxy radicals involved together with AH",(NO) = 21.6 kcal/mole leads to the result D(R0-NO) = 41.5 f 1 kcal/mole. The concordance between D(thermochemica1) and D(kinetic), unlike previous kinetic studies, implies that E t = 0 =k 1 kcal/mole.

The rate of decomposition of ethyl nitrite (EN) has been studied in a static system over the temperature range of 162‐218°C. The main products are formaldehyde, acetaldehyde, ethanol, and nitrous oxide. For low concentrations of EN (10−5‐10−4M), but with a high total pressure of CF4 (∼0.9 atm) and small extents of reaction (2‐6%), the first‐order homogeneous rates of CH2O formation are a direct measure of reaction (1), since k3bk2(NO): Addition of large amounts of NO(∼0.9 atm) completely suppressed CH2O formation in agreement with the observed value for k3b. The rate of reaction (1) is given by k1 = 1016.0‐41.8/θ−1. Since (E1 + RT) and ΔH±1 are identical, both may be equated with D(EtO‐NO) = 42.4 ± 0.9 kcal/mol and E2 = O± 1 kcal/mol. The thermochemistry leads to the result ΔHDelta;f(EN) = ‐24.5 ± 1 kcal/mol. From ΔS1 and A1, k2 is calculated to be 1010.3M−1θ−1. From an independent observation that k6/k2 = 0.3 ± 0.05 independent of temperature it is concluded that k6 = 109.8M−1Δ−1. The addition of NO has no effect on the AcH yields. Although the yields of AcH are affected by the surface‐to‐volume ratio of different reaction vessels, it is concluded that in a spherical reaction vessel, the AcH arises as the result of an essentially homogeneous elimination of HNO from EN(5): and reaction (6). The rate of AcH formation is given by kobs = 1013.7‐37.5/θ−1. By using isobutane (t‐BuH) as a radical trap for EtO (4), a value for k3b was determined to be 1015.0‐21.6/θ s−1. From an independent observation that k2:k2:k6:k6 was 1: 0.4: 0.3: 0.18 we find k2θ = 109.9M−1→ s−1, k1θ = 1016.0‐40.0/θ s−1, and k6± = 109.6M−1 · s−1.

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The rate of decomposition of t‐butyl nitrite (TBN) has been studied in a static system over the temperature range of 120–160°C. For low concentrations of TBN (10−5‐ 10−4M), but with a high total pressure of CF4 (∼0.9 atm) and small extents of reaction (∼1%), the first‐order homogeneous rates of acetone (M2K) formation are a direct measure of reaction (1), since k3» k2 (NO): TBN . Addition of large amounts of NO in place of CF4 almost completely suppresses M2K formation. This shows that reaction (1) is the only route for this product. The rate of reaction (1) is given by k1 = 1016.3–40.3/θ s−1. Since (E1 + RT) and ΔH °1 are identical, both may be equated with D(RO‐NO) = 40.9 ± 0.8 kcal/mole and E2 = O ± 1 kcal/mole. From ΔS °1 and A1, k2 is calculated to be 1010.4M−1 ·s−1, implying that combination of tBuO and NO occurs once every ten collisions. From an independent observation that k2/k2′ = 1.7 ± 0.25 independent of temperature, it is concluded that k2′ = 1010.2M−1 · s−1 and k1′ = 1015.9−40.2/θ s−1; . This study shows that MeNO arises solely as a result of the combination of Me and NO. Since NO is such an excellent radical trap for t‐Bu\documentclass{article}\pagestyle{empty}\begin{document}${\rm Me\dot O}$\end{document}, reaction (2) may be used in a competitive study of the decomposition of tBu\documentclass{article}\pagestyle{empty}\begin{document}${\rm Me\dot O}$\end{document} in order to obtain the first absolute value for k3. Preliminary results show that k3 (∞) = 1015.7–17.0/θ s−1. The pressure dependence of k3 is demonstrated over the range of 10−2−1 atm (160°C). The thermochemistry for reaction (3) implies that the Hg 6(3P1) sensitised decomposition of t‐BuOH occurs via reaction (m): In addition to the products accounted for by the TBN radical split, isobutene is formed as a result of the 6‐centre elimination of HONO: TBN \documentclass{article}\pagestyle{empty}\begin{document}$\mathop \to \limits^7 $\end{document} isobutene + HONO. The rate of formation of isobutene is given by k7 = 1012.9–33.6/θ s−1. t‐BuOH, formed at a rate comparable to that of isobutene–at least in the initial stages–is thought to arise as a result of secondary reactions between TBN and HONO. The apparent discrepancy between this and previous studies is reconciled in terms of the above parallel reactions (1) and (7), such that k + 2k7 = 1014.7–36.2/θ s−1.