Radical reactions in the photodeccomposition of benzoyl peroxide in solid polycarbonate

Conclusions The decomposition of benzoyl peroxide in solid polycarbonate under UV irradiation is a monomolecular chain process.This process is accompanied by the intensive formation of colored products. After complete decomposition of the benzoyl peroxide, this process passes over to a new initiator stage for continued photoreaction of the polycarbonate. A reaction scheme is proposed which involves chain radical reactions, some with participation of polycarbonate macroradicals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 66–74, January, 1977.     

Heating of dye-doped microparticles filled with aggregated metal-containing nanostructures by optical radiation

It is found that localizing hot spots inside a resonance microparticle doped with a dye and filled with nanosized metal particles strongly affects heating of these particles and of the entire microparticle. If hot spots lie in the resonance region in the dark or illuminated hemisphere of the microparticle, the microsphere is heated considerably faster. Hot spots in the dark hemisphere of the microparticle may be heated to a maximal temperature sooner than the resonance region in the dark hemisphere.     

Synthesis and characterization of A4[Re6Q8L6]@SiO2 red-emitting silica nanoparticles based on Re6 metal atom clusters (A = Cs or K, Q = S or Se, and L = OH or CN)

Metal atom clusters constitute very promising candidates as luminophores for applications in biotechnology because they are nanosized entities offering robust luminescence in the near-infrared field (NIR). However, they cannot be used as prepared for biological applications because of potential toxic effects and quenching of the clusters' luminescence in aqueous media, and they therefore need to be dispersed in a biocompatible matrix. We describe herein the encapsulation of octahedral rhenium clusters, denoted as A(4)[Re(6)Q(8)L(6)] (A = Cs or K, Q = S or Se, and L = OH or CN), in silica nanoparticles by a water-in-oil microemulsion process, paying particular attention to the clusters' stability. The obtained A(4)[Re(6)Q(8)L(6)]@SiO(2) nanoparticles are 30 nm in size with good monodispersity and a perfectly spherical shape, as shown by scanning electron microscopy (SEM). The presence of cluster units inside the silica matrix was evidenced by scanning transmission electron microscopy in annular dark-field mode (ADF-STEM). From the point of view of their optical properties, the A(4)[Re(6)Q(8)L(6)]@SiO(2) nanoparticles show red and NIR emission under UV excitation, even when dispersed in water. The evolution of the structural and luminescence properties of clusters before and after encapsulation was followed by Raman and photoluminescence spectroscopy.     

The effect of radiation on dye-doped polystyrene microspheres coated by a thin silver layer

The heat conduction equation is analyzed theoretically and numerically for the case of the effect of laser radiation on two-layer spherical particles. The internal heat sources and the temperature distribution are calculated for particles whose core of dye-doped polystyrene is coated by a deposited silver layer. The distribution of heat sources inside such a two-component microsphere is shown to depend significantly on the core radius and the shell thickness. Therefore, these parameters strongly affect the heating of particles. In particular, an increase in the thickness of the deposited silver layer may either reduce or strongly increase the heating time of two-layer microspheres.     

Coordination polymers based on [Re6Se8(CN)6]4? cluster anion, lanthanide cations, and tetraatomic alcohol erythritol

By the interaction of aqueous solutions of salts of the [Re₆Se₈(CN)₆]⁴⁻ cluster anion with salts of Nd(III), Tb(III), and Yb(III) lanthanides in the presence of tetraatomic alcohol erythritol (butane-1,2R,3S,4-tetraol) three new compounds are obtained: K[Nd(C₄H₁₀O₄)(H₂O)₄{Re₆Se₈(CN)₆}]·4H₂O (P $ \bar 1 $ \bar 1 space group, a = 11.544 ?, b = 13.643 ?, c = 13.838 ?, α = 111.97°, β = 108.08°, γ = 90.08°) (1); [{Yb₂(C₄H₉O₄)₂ × (H₂O)₂}{Re₆Se₈(CN)₆}]·5H₂O (P $ \bar 1 $ \bar 1 space group, a = 10.308 ?, b = 10.505 ?, c = 11.154 ?, α = 88.21°, β = 81.83°, γ = 78.50°) (2); [{Tb₂(C₄H₉O₄)₂(C₄H₁₀O₄)}{Re₆Se₈(CN)₆}]·4H₂O (P $ \bar 1 $ \bar 1 space group, a = 10.002 ?, b = 10.276 ?, c = 11.762 ?, α = 91.32°, β = 104.01°, γ = 106.02°) (3). The structures of these compounds are the coordination polymers (chain (2) and grids (1 and 3)) with different coordination modes of erythritol to the lanthanide cations.     

Transformation of polycarbonate based on 1,1-di-(4-hydroxyphenyl)-1-phenylethane under the influence of light in the presence of ferric chloride

Conclusions The photodecomposition of ferric chloride in a polycarbonate based on 1,1-di-(4-hydroxyphenyl)-1-phenylethane leads to cleavage of the macromolecule at the carbonate group and the formation of radicals presumably of the phenyl type, which are localized on the macrochains.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 642–644, March, 1973.