Publications by authors named "Terry J Dillon"

Cleaning products emit a range of volatile organic compounds (VOCs), including some which are hazardous or can undergo chemical transformations to generate harmful secondary pollutants. In recent years, "green" cleaners have become increasingly popular, with an implicit assumption that these are better for our health and/or the environment. However, there is no strong evidence to suggest that they are better for indoor air quality compared to regular products.

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We have developed and tested two-photon excited fragment spectroscopy (TPEFS) for detecting HNO in pulsed laser photolysis kinetic experiments. Dispersed (220-330 nm) and time-dependent emission at (310 ± 5) nm following the 193 nm excitation of HNO in N, air and He was recorded and analysed to characterise the OH(AΣ) and NO(AΣ) electronic excited states involved. The limit of detection for HNO using TPEFS was ∼5 × 10 molecule cm (at 60 torr N and 180 μs integration time).

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Absolute (pulsed laser photolysis, 4-639 Torr N(2) or air, 240-357 K) and relative rate methods (50 and 760 Torr air, 296 K) were used to measure rate coefficients k(1) for the title reaction, OH + C(4)H(5)N → products (R1). Although the pressure and temperature dependent rate coefficient is adequately represented by a falloff parametrization, calculations of the potential energy surface indicate a complex reaction system with multiple reaction paths (addition only) in the falloff regime. At 298 K and 760 Torr (1 Torr = 1.

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Nitrogen trifluoride, NF(3), a trace gas of purely anthropogenic origin with a large global warming potential is accumulating in the Earth's atmosphere. Large uncertainties are however associated with its atmospheric removal rate. In this work, experimental and theoretical kinetic tools were used to study the reactions of NF(3) with three of the principal gas-phase atmospheric oxidants: O((1)D), OH and O(3).

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Pulsed laser photolysis radical generation is used to study the title reaction IO+CH(3)O(2)→products. Sensitive and selective laser-induced fluorescence detection of IO allows excess CH(3)O(2) conditions to be maintained throughout, ensuring minimal interference from other fast IO reactions. The rate coefficients, k(5)(296 K)=(3.

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The technique of pulsed laser photolysis coupled to LIF detection of IO was used to study IO + NO(3) --> OIO + NO(2); I + NO(3) --> (products); CH(2)I + O(2) --> (products); and O((3)P) + CH(2)I(2) --> IO + CH(2)I, at ambient temperature. was observed for the first time in the laboratory and a rate coefficient of k(1 a) = (9 +/- 4) x 10(-12) cm(3) molecule(-1) s(-1) obtained. For , a value of k(2) (298 K) = (1.

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Absolute rate coefficients for the title reaction, HO+HOCH2CHO-->products (R1), were measured over the temperature range 240-362 K using the technique of pulsed laser photolytic generation of the HO radical coupled to detection by pulsed laser induced fluorescence. Within experimental error, the rate coefficient, k1, is independent of temperature over the range covered and is given by k1(240-362 K)=(8.0+/-0.

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The technique of pulsed laser photolysis was coupled to laser induced fluorescence detection of iodine oxide (IO) to measure rate coefficients, k for the reactions IO + CH(3)O(2)--> products (R1, 30-318 Torr N(2)), IO + CF(3)O(2)--> products (R2, 70-80 Torr N(2)), and IO + O(3)--> OIO + O(2) (R3a). Values of k(1) = (2 +/- 1) x 10(-12) cm(3) molecule(-1) s(-1), k(2) = (3.6 +/- 0.

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Laser-induced fluorescence spectroscopy via excitation of the A2pi(3/2) <-- X2pi(3/2) (2,0) band at 445 nm was used to monitor IO in the presence of NO2 following its generation in the reactions O(3P) + CF3I and O(3P) + I2. Both photolysis of O3 (248 nm) and NO2 (351 nm) were used to initiate the production of IO. The rate coefficients for the thermolecular reaction IO + NO2 + M --> IONO2 + M were measured in air, N2, and O2 over the range P = 18-760 Torr, covering typical tropospheric conditions, and were found to be in the falloff region.

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The technique of pulsed laser photolysis was coupled to laser induced fluorescence detection of iodine oxide (IO) to measure rate coefficients, k(1)(T), for the title reaction IO + CH3SCH3 --> products (R1). A value of k1(298 K) = (1.44 +/- 0.

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Absolute rate coefficients for the title reaction, HO + HOCH(2)C(O)CH(3)--> products (R1) were measured over the temperature range 233-363 K using the technique of pulsed laser photolytic generation of the HO radical coupled to detection by pulsed laser induced fluorescence. The rate coefficient displays a slight negative temperature dependence, which is described by: k(1)(233-363 K) = (2.15 +/- 0.

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Laser flash photolysis coupled to resonance-fluorescence detection of I atoms was used to measure the rate coefficients for the reactions: I + O3 --> IO + O2 (R1), O + I2 --> IO + I (R6) and I + NO2 + M --> INO2 + M (R7). All experiments were conducted under pseudo first-order conditions, and the accuracy of the results was enhanced by online determination of reagent concentrations by optical absorption. Bimolecular rate coefficients for reactions (R1) and (R6) were determined to be k1 = (1.

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