- Regularities of the formation of the photolysis products in the lead azide-cadmium system
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Compared to PbN6(Ab), the PbN6(Ab)-Cd system was found to be characterized by a low photolysis rate within the region of intrinsic absorption of PbN6(Ab) and, at the same time, by a broader range of spectral sensitivity of PbN6(Ab), up to 510 nm. Preliminary irradiation by 380-nm light resulted in an increase in the photolysis rate. The photolysis rate constants for the PbN6(Ab)-Cd system were determined. An analysis of the voltammetric characteristics, photocurrent, and contact potential difference made it possible to develop a model of the photolysis of the PbN6(Ab)-Cd system, including the stages of generation, recombination, redistribution of nonequilibrium charge carriers in the contact field, the photoemission of electrons, formation of the photolysis products, and genesis of the PbN6(Ab)-Pb(photolysis product)-Cd system. It was demonstrated that the diffusion of anionic vacancies to neutral Pb n 0 sites is the limiting stage of the photolysis of the PbN 6(Ab)-Cd system. Nauka/Interperiodica 2006.
- Surovoi,Bugerko,Rasmatova
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- Rules governing the formation of photolysis products in the lead azide-copper(I) oxide system
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It was found that, along with a decrease in the rate of photolysis and photocurrent in the region of lead azide intrinsic absorption, the addition of copper(I) oxide broadened the range of spectral sensitivity, and preliminary treatment of the PbN6(Ab)-Cu2O system with light (λ = 365 nm) increased the rate of photolysis. The rate constants for photolysis were estimated. An analysis of the results of current-voltage characteristic, contact potential difference, and contact photo-electromotive force measurements was used to construct a diagram of energy zones and suggest a model of the photolysis of the PbN6(Ab)-Cu2O system including stages of the generation, recombination, and redistribution of nonequilibrium carriers in a contact field, formation of microheterogeneous PbN6(Ab)-Pb (photolysis product) systems, and formation of final photolysis products.
- Surovoi,Bugerko,Rasmatova,Bin
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- PbII-catalyzed transformation of aromatic nitriles to heptanitrogen anions via sodium azide: a combined experimental and theoretical study
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Under hydrothermal conditions, an open-chain N73? anion stabilized in a metal-organic framework (MOF) was achieved for the first time via the in situ reaction of 4-fluorobenzonitrile and sodium azide with Pb2+ ion as catalyst. The anion with C2h symmetry in the MOF was studied by FT-IR, single-crystal XRD and theoretical calculations. Thermal analysis results demonstrated the stability of the anion in the MOF below 430 °C and a high energy content of 8.61 kJ g?1. The anion is also a good reducing agent. It can easily react with basic KMnO4 solution. Moreover, the present study indicates that the Pb2+ ion activates the azide rather than nitrile in the in situ reaction of nitriles with azides to form polynitrogen and this mechanism is a distinct contradiction with the previous results in which the nitrile reacts with azide in the presence of transition metal ions. Our findings may open a new avenue towards the synthesis and capture of polynitrogen compounds.
- Huang, Rong-Yi,Zhang, Chao,Yan, Da,Xiong, Zhi,Xu, Heng,Ren, Xiao-Ming
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- Kinetics of the formation of photolysis products in the lead azide-cadmium telluride systems
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The kinetic and spectral regularities of the formation of the gaseous (nitrogen) and solid-phase (lead) products of the photolysis of lead azide in contact with cadmium telluride at different intensities of the incident light with λ = 380 nm were investigated by mass spectrometry and spectrophotometry. Rate constants of the photolysis of PbN6(Ab)-CdTe systems were determined. It was shown that, during the formation of PbN 6(Ab)-CdTe systems, the photolysis rate in the absorption region of PbN6(Ab) is decreased, and the region of spectral sensitivity of lead azide is broadened. Based on a consideration of measured current-voltage characteristics, photocurrent and photo-emf values, and contact potential differences, a model of the photolysis of PbN6(Ab)-CdTe systems was proposed. The model involves the stages of generation, recombination, and redistribution of nonequilibrium carriers in the contact field, formation of the photolysis products, and also formation of PbN6(Ab)-Pb (photolysis product)-CdTe heterogeneous systems. Copyright
- Surovoi,Bugerko,Rasmatova
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p. 981 - 985
(2007/10/03)
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- Kinetic regularities of the effect of the products on the photolysis of lead azide
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Mass spectrometry, spectrophotometry, and electron microscopy studies show that a preliminary irradiation of lead azide with a 380-nm light at a photon irradiance of I = 2 × 1015 quanta/(cm2 s) results in increases in the photolysis rate and photocurrent and in the appearance of a new long-wave (up to 850 nm) photosensitivity range. The constant rate for the photolysis of lead azide is determined. Measurements of the contact potential difference, voltampere characteristic, contact photovoltage, and photocurrent suggest that the photolysis of lead azide is accompanied by the formation of PbN6(Ab)-Pb microheterogeneous systems (Pb is a photolytic product). Dark and photoinduced processes at the interfaces between these systems determine the observed changes in the photosensitivity of PbN6(Ab). It is demonstrated that the limiting stage of the formation of photolytic lead is the diffusion of anionic vacancies to neutral Pbn0 sites.
- Surovoi,Bugerko,Rasmatova
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p. 561 - 565
(2007/10/03)
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