Reactions of H<sup>+</sup>(pyridine)<sub><i>m</i></sub>(H<sub>2</sub>O)<sub><i>n</i></sub> and H<sup>+</sup>(NH<sub>3</sub>)<sub>1</sub>(pyridine)<sub><i>m</i></sub>(H<sub>2</sub&

Abstract

Abstract. Reactions between pyridine containing water cluster ions, H+(pyridine)1(H2O)n, H+(pyridine)2(H2O)n and H+(NH3)1(pyridine)1(H2O)n (n up to 15) with NH3 have been studied experimentally using a quadrupole time-of-flight mass spectrometer. The product ions in the reaction between H+(pyridine)m(H2O)n (m = 1 to 2) and NH3 have been determined for the first time. It is found that the reaction mainly leads to cluster ions of the form H+(NH3)1(pyridine)m(H2O)n-x, with x = 1 or 2 depending on the initial size of the reacting cluster ion. For a given number of water molecules (from 5 to 15) in the cluster ion, rate coefficients are found to be slightly lower than those for protonated pure water clusters reacting with ammonia. The rate coefficients obtained from this study are used in a kinetic cluster ion model under tropospheric conditions. The disagreement between ambient ground level measurements and previous models are discussed in relation to the results from our model and future experimental directions are suggested.

CO2incorporation in hydroxide and hydroperoxide containing water clusters—a unifying mechanism for hydrolysis and protolysis

“…The experiments were performed using a quadrupole-time-of-flight mass spectrometer (QTOF2, Micromass/Waters, Manchester UK), as previously used by us. [45][46][47][48][49][50] The instrument has been modified to allow for volatile and semi-volatile gases to be injected into the instrument's collision-cell via a stainless steel inlet system.…”

The link between atmospheric radicals and newly formed particles at a spruce forest site in Germany

“…Homogeneous nucleation by multiple compounds (heteromolecular) requires a substantial interaction between compounds such as present in the binary or ternary nucleation of sulfuric acid-water and of sulfuric acid-water-ammonia or amines (Friedlander, 2000;Seinfeld and Pandis, 2006;Kirkby et al, 2011;Paasonen et al, 2012). These intermolecular interactions such as acid-base stabilisation (Kirkby et al, 2011;Ryding et al, 2012) lower the critical energy that is required to form the new particle phase. There are two further established physico-chemical effects that may cause a drop in the nucleation barrier energy: (i) the solution (Raoult) effect like in the case of watersoluble species and (ii) the ionic (Thompson) effect (Friedlander, 2000;Jacobson, 2005;Seinfeld and Pandis, 2006).…”

Substitution effect on the intermolecular halogen and hydrogen bonds of the σ‐bonded fluorinated pyridine···XY/HX complexes (XY = F2, Cl2, ClF; HX = HF, HCl)

“…Recently, the reactions of pyridine and its substituted derivatives in atmospheric chemistry were also studied . The main sources of these species were reported to be biomass burning, automobile exhaust, coal tars, and others . Conversely, the reaction with atomic chlorine is named within the tree dominant sinks of the atmospheric pyridine in the troposphere.…”