Reference

Rate constants for the gas-phase reactions of nitrate radicals with a series of organics in air at 298 ± 1 K

Rate constants for the gas-phase reactions of nitrate radicals with a series of organics in air at 298 ± 1 K. Atkinson, Roger; Plum, Christopher N.; Carter, William P. L.; Winer, Arthur M.; Pitts, James N., Jr. (Statewide Air Pollut. Res. Cent., Univ. California, Riverside, CA 92521, USA). J. Phys. Chem., 88(6), 1210-15 (English) 1984. CODEN: JPCHAX. ISSN: 0022-3654. DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution and Industrial Hygiene) Section cross-reference(s): 67 The NO3 radical [12033-49-7] is an important intermediate species in NOx-O3-air systems, but relatively few data are available concerning its reactions with orgs. The rate consts. were detd. for the gas-phase reactions of NO3 radicals with a series of org. compds. at 298 ± 1 K by 2 exptl. techniques, one by monitoring the enhanced decay rates of N2O5 in the presence of a reactive org. and the other by use of a relative rate technique. Based upon the most recent literature evaluation concerning the N2O5 (+M) t NO2 + NO3 reactions and equil. const., the rate consts. (in cm3/mol.-s units) detd. were C2H4 [74-85-1], (6.1 ± 2.6) ′ 10-17; propene [115-07-1], (4.2 ± 0.9) ′ 10-15; 1-butene [106-98-9], (5.4 ± 1.2) ′ 10-15; isobutene [115-11-7], (1.70 ± 0.19) ′ 10-13; cis-2-butene [590-18-1], (1.89 ± 0.22) ′ 10-13; trans-2-butene [624-64-6], (2.11 ± 0.24) ′ 10-13; 2-methyl-2-butene [513-35-9] (5.1 ± 1.6) ′ 10-12; 2,3-dimethyl-2-butene [563-79-1], (3.1 ± 1.0) ′ 10-11; C6H6 [71-43-2], ￡1.1 ′ 10-17; PhMe [108-88-3] (2.0 ± 1.1) ′ 10-17; m-xylene [108-38-3] (7.6 ± 3.5) ′ 10-17; naphthalene [91-20-3] (6.4 ± 2.5) ′ 10-15; HCHO [50-00-0], (3.23 ± 0.26) ′ 10-16, and MeCHO [75-07-0], (1.There are some commonly used reagents with their cas registry numbers 74-85-1 and 71-43-2 in this article.34 ± 0.28) ′ 10-15. These rate consts. for the alkenes (apart from C2H4) and MeCHO are in good agreement with the only previous set of literature values, while arom. hydrocarbons were obsd. for the 1st time to react with the NO3 radical. Thus, the rate const. for m-xylene is comparable to that for C2H4, and naphthalene reacts with the NO3 radical a factor of 1.5 faster than does propene. MeCHO is significantly more reactive than is HCHO towards NO3 radicals, analogous to their reactions with O(3P) atoms and OH radicals. The atm. implications of these data, with regard to the loss of NO3 radicals and org. compds. and the formation of HNO3 and hence acid deposition, are briefly discussed. .

Oxidative dehydrogenation of butenes to butadiene

Oxidative dehydrogenation of butenes to butadiene. Ogonowski, Jan (Inst. Chem. Technol. Org., Politech. Krakowska, Krakow, Pol. 106-98-9 and 7439-98-7 are also occured in this study.). Przem. Chem., 62(11), 610-12 (Polish) 1983. CODEN: PRCHAB. ISSN: 0033-2496. DOCUMENT TYPE: Journal CA Section: 39 (Synthetic Elastomers and Natural Rubber) Section cross-reference(s): 23 The effect of temp. and catalyst load was detd. on the formation of 1,3-butadiene [106-99-0] in dehydrogenation on a Mo-Bi catalyst of a mixt. comprising 1-butene (I) [106-98-9] 28.2, cis-2-butene (II) [590-18-1] 14.7, and trans-2-butene (III) [624-64-6] 56.5%. A decrease in the vol. of charged butenes from 164 to 41 mL (pulsed method, and of the catalyst 0.1 g) did not affect conversion (64.5%) and selectivity (94.5%). A further decrease in the vol. of charged butenes decreased the selectivity. At 693 K, the conversion and selectivity were 2.8 and 69%, resp. At 773 K, the corresponding values were 23.5 and 93.6%. Above 773 K, deep oxidn. became more significant. The reactivity of butenes increased in the sequence III < II < I. .