《Reactivity Trends in the Gas-Phase Addition of Acetylene to the N-Protonated Aryl Radical Cations of Pyridine, Aniline, and Benzonitrile》 was written by Shiels, Oisin J.; Kelly, P. D.; Bright, Cameron C.; Poad, Berwyck L. J.; Blanksby, Stephen J.; da Silva, Gabriel; Trevitt, Adam J.. Reference of 4-Iodopyridine And the article was included in Journal of the American Society for Mass Spectrometry in 2021. The article conveys some information:
A key step in gas-phase polycyclic aromatic hydrocarbon (PAH) formation involves the addition of acetylene (or other alkyne) to σ-type aromatic radicals, with successive additions yielding more complex PAHs. A similar process can happen for N-containing aromatics In cold diffuse environments, such as the interstellar medium, rates of radical addition may be enhanced when the σ-type radical is charged. This paper investigates the gas-phase ion-mol. reactions of acetylene with nine aromatic distonic σ-type radical cations derived from pyridinium (Pyr), anilinium (Anl), and benzonitrilium (Bzn) ions. Three isomers are studied in each case (radical sites at the ortho, meta, and para positions). Using a room temperature ion trap, second-order rate coefficients, product branching ratios, and reaction efficiencies are measured. The rate coefficients increase from para to ortho positions. The second-order rate coefficients can be sorted into three groups: low, between 1 and 3 x 10-12 cm3 mol.-1 s-1 (3Anl and 4Anl); intermediate, between 5 and 15 x 10-12 cm3 mol.-1 s-1 (2Bzn, 3Bzn, and 4Bzn); and high, between 8 and 31 x 10-11 cm3 mol.-1 s-1 (2Anl, 2Pyr, 3Pyr, and 4Pyr); and 2Anl is the only radical cation with a rate coefficient distinctly different from its isomers. Quantum chem. calculations, using M06-2X-D3(0)/6-31++G(2df,p) geometries and DSD-PBEP86-NL/aug-cc-pVQZ energies, are deployed to rationalize reactivity trends based on the stability of prereactive complexes. The G3X-K method guides the assignment of product ions following adduct formation. The rate coefficient trend can be rationalized by a simple model based on the prereactive complex forward barrier height. The results came from multiple reactions, including the reaction of 4-Iodopyridine(cas: 15854-87-2Reference of 4-Iodopyridine)
4-Iodopyridine(cas: 15854-87-2) belongs to pyridine. Pyridine and its simple derivatives are stable and relatively unreactive liquids, with strong penetrating odours that are unpleasant.Reference of 4-Iodopyridine
Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com