Temperature-dependent rate constants for the gas-phase reactions of OH radicals with 1,3,5-trimethylbenzene, triethyl phosphate, and a series of alkylphosphonates

Rate constants for the reactions of OH radicals with dimethyl methylphosphonate [DMMP, (CH3O)(2)P(O)CH3], dimethyl ethylphosphonate [DMEP, (CH3O)(2)P(O)C2H5], diethyl methylphosphonate [DEMP, (C2H5O)(2)P( O)CH3], diethyl ethylphosphonate [DEEP, (C2H5O)(2)P(O)C2H5], triethyl phosphate [TEP, (C2H5O)(3)PO] and 1,3,5-trimethylbenzene have been measured over the temperature range 278-348 K at atmospheric pressure of air using a relative rate method. alpha-Pinene (for DEMP, DEEP, TEP and 1,3,5-trimethylbenzene) and dinbutyl ether ( for DMMP and DMEP) were used as the reference compounds, and rate constants for the reaction of OH radicals with di-n-butyl ether were also measured over the same temperature range using alpha-pinene and n-decane as the reference compounds. The Arrhenius expressions obtained for these OH radical reactions (in cm(3) molecule(-1) s(-1) units) are 8.00 x 10(-14)e((1470(132)/T) for DMMP (296 - 348 K), 9.76 x 10(-14)e((1520(14)/T) for DMEP (296 - 348 K), 4.20 x 10(-13)e((1456(227)/T) for DEMP (296 - 348 K), 6.46 x 10(-13)e((1339(376)/T) for DEEP (296 - 348 K), 4.29 x 10(-13)e((1428(219)/T) for TEP (296 - 347 K), and 4.40 x 10(-12)e((738(176)/T) for 1,3,5-trimethylbenzene (278 - 347 K), where the indicated errors are two least-squares standard deviations and do not include the uncertainties in the rate constants for the reference compounds. The measured rate constants for di-n-butyl ether are in good agreement with literature data over the temperature range studied (278 - 348 K).