Reaction kinetics of the CN radical with primary alcohols

Abstract

The kinetics of the reactions of CN radicals with several small primary alcohol molecules were studied by transient infrared laser absorption spectroscopy. Direct time-resolved detection of CN was used to determine total rate constants. In addition, HCN and DCN products were detected in order to estimate the branching ratios of the CN + CH 3 OH reaction. We find that abstraction of an alkyl hydrogen atom dominates the CN + CH 3 OH reaction, but a small, ~8% yield of hydroxyl hydrogen abstraction is also observed.

Low Temperature Kinetics of the Reaction Between Methanol and the CN Radical

“…Hershberger 53 who obtained a rate coefficient of 1.03 × 10 −11 cm 3 s −1 at room temperature, which is in good agreement with the value reported here of (1.6 ± 0.2) × 10 −11 cm 3 s −1 . It is unclear why the value measured by Sayah et al is faster than these three essentially independent measurements by an order of magnitude.…”

European Pulsar Timing Array limits on continuous gravitational waves from individual supermassive black hole binaries

“…Those consist of posterior probability distributions for the relevant noise parameters (EFAC, EQUAD, DM and intrinsic red noise), together with their maximum likelihood (ML) values. Extensive noise analyses on the same dataset are fully detailed in Janssen et al (2015); Caballero et al (2015), and the posterior distributions of the noise parameters of the three most sensitive pulsars in our array (J1909−3744, J1713+0747, J1744−1134) are also given in Figure 3 of the companion paper Lentati et al (2015). In most cases we fix the noise parameters to their ML value, but we also perform separate searches sampling from the posterior distribution or searching simultaneously over the signal and the noise parameters, as described in Section 3 and summarized in Table 1.…”

“…Some of the noise parameters (like pulsar-intrinsic red noise or clock and ephemeris errors) are correlated with the GW parameters and one should in principle fit for noise and GW parameters simultaneously. However, such a multidimensional search is computationally very expensive, and in most of the searches detailed below, we use noise characteristics derived from the SPA introduced in Section 2.1 and extensively described in Janssen et al (2015); Caballero et al (2015). We characterise the noise by considering the data from each pulsar separately (as given by the SPA), and to exclude any potential bias we also considered a model "noise + monochromatic signal".…”

“…The timing residuals are the difference between the observed TOAs and the TOAs predicted by the best-fit model, and they carry information about unaccounted noise and potentially unmodelled physical effects, such as GWs, in the datastream (e.g. Hellings & Downs 1983;Jenet et al 2005). The European Pulsar Timing Array (EPTA, Kramer & Champion 2013), the Parkes Pulsar Timing Array (PPTA, Hobbs 2013) and the North American Nanohertz Observatory for Gravitational Waves (NANOGrav, McLaughlin 2013), joining together in the International Pulsar Timing Array (IPTA, Hobbs et al 2010;Manchester & IPTA 2013), are constantly improving their sensitivity in the frequency range of ∼ 10 −9 − 10 −6 Hz.…”

Reaction kinetics of the CN radical with methyl bromide

“…Previous kinetic studies of CN reactions include measurements with a variety of molecules such as saturated and unsaturated hydrocarbons [1][2][3][4][5][6][7][8][9][10][11][12][13], O 2 [1,[14][15][16][17][18][19][20][21][22], NO [21,23], and NO 2 [22,23]. Past work in our laboratory has included study of CN reactions with O 2 [24,25], NO 2 [26], OCS [27], CS 2 [28], SO 2 [28], HCNO [29,30], small primary alcohols [31], and chlorinated methanes including CH 3 Cl [32]. To date, however, there is no experimental literature on the kinetics of CN reactions with CH 3 Br, methyl bromide.…”