(CH3)3COOH (tert-butyl hydroperoxide): OH reaction rate coefficients between 206 and 375 K and the OH photolysis quantum yield at 248 nmElectronic supplementary information (ESI) available: UV absorption cross section data for (CH3)3COOH between 210 and 300 nm. See DOI: 10.1039/c0cp00463d

Rate coefficients, k , for the gas-phase reaction of the OH radical with (CH 3 ) 3 COOH ( tert -butyl hydroperoxide) were measured as a function of temperature (206-375 K) and pressure (25-200 Torr (He, N 2 )). Rate coefficients were measured under pseudo-first-order conditions using pulsed laser photolysis to produce OH and laser induced fluorescence (PLP-LIF) to measure the OH temporal profile. Two independent methods were used to determine the gas-phase infrared cross sections of (CH 3 ) 3 COOH, absolute pressure and chemical titration, that were used to determine the (CH 3 ) 3 COOH concentration in the LIF reactor. The temperature dependence of the rate coefficients is described, within the measurement precision, by the Arrhenius expression k 1 ( T ) = (7.0 ± 1.0) × 10 −13 exp[(485 ± 20)/ T ] cm 3 molecule −1 s −1 where k 1 (296 K) was measured to be (3.58 ± 0.54) × 10 −12 cm 3 molecule −1 s −1 . The uncertainties are 2 σ (95% confidence level) and include estimated systematic errors. UV absorption cross sections of (CH 3 ) 3 COOH were determined at 185, 214, 228, and 254 nm and over the wavelength range 210-300 nm. The OH quantum yield following the 248 nm pulsed laser photolysis of (CH 3 ) 3 COOH was measured relative to the OH quantum yields of H 2 O 2 and HNO 3 using PLP-LIF and found to be near unity. Temperature dependence of the rate coefficient for the OH + (CH 3 ) 3 COOH reaction in the gas-phase.