57835-92-4Relevant articles and documents
Effect of the blocked-sites phenomenon on the heterogeneous reaction of pyrene with N2O5/NO3/NO2
Zhang, Peng,Sun, Wanqi,Yang, Bo,Shu, Jinian,Dong, Liang
, p. 10358 - 10364 (2016/02/05)
To clarify whether the blocking reaction sites problem has a significant impact on heterogeneous reactions, experiments contrasting the order of pyrene (PY) particles' exposure to N2O5-O3 or O3-N2O5 in a heterogeneous process were conducted. Additionally, PY particles were exposed to N2O5 (～8 ppm) in the presence of O3 (2.5-30 ppm) in a reaction chamber at ambient pressure and room temperature. Our results show that the phenomenon of blocking reaction sites may be ubiquitous on the surfaces of atmospheric aerosol particles, and the N2O5-initiated ionic electrophilic nitration may be promoted by NO3 radical-initiated heterogeneous reactions on the aerosol particle surface. We also found that the operative reaction mechanism strongly depends on the concentrations of the nitric oxides in the atmosphere. Our results provide an explanation as to why 2-nitropyrene (2-NPY), one of the most ubiquitous nitro-polyaromatic hydrocarbon pollutants that exists in both the gas and particle phases, was not observed in previous experiments on the heterogeneous reactions of PY and N2O5/NO3/NO2.
Abnormal orientation in nitration of anthracene, pyrene, and perylene with pyridinium nitrate. 2-Nitroanthracene and 4-nitropyrene
Nefedov
, p. 1165 - 1171 (2007/10/03)
Nitration by undissociated nitric acid which presumably forms at thermolysis (115°C) of pyridinium nitrate in pyridine selectively proceeds with respect to aromatic substrates and nonselectively with respect to various positions in aromatic rings. Whereas in electrophilic nitration forms a single isomer of mononitro products, the process under study yields two mononitro isomers, and nitration occurs only with polycyclic hydrocarbons containing a butadiene fragment included into neighboring rings (anthracene, naphthacene, pyrene, and perylene). On the contrary, benzene and its derivatives, naphthalene, phenanthrene, and triphenylene are not nitrated. Beside pyridinium nitrate as nitrating agents giving two isomeric mononitro arenes from polycyclic compounds are used tetranitromethane in pyridine and ammonium nitrate in a mixture pyridine-acetic anhydride. The side products of the reaction are biaryls, quinones (in particular, with unusually located carbonyl groups), and dyes containing aci-nitro and oxo groups.
