Systems, based on aqueous suspensions of single walled carbon nanotubes, stabilized by surfactants, and having supramolecular ordering are studied by spectroscopy and polarized microscopy. Nonlinear optical behavior of the suspensions has been checked. A correlation between sizes of aggregate in suspension and nonlinear optical limiting parameters has been found. A nematic meso-phase based on suspension of carbon nanotubes has been obtained.
We resume a complex study of a new Coproporphyrin III preparation obtained in vitro via microbiological synthesis
in environment of a cultural medium of Arthrobacter globiformis with gaining of the coproporphyrin III tetrapotash salt
sterilized aqueous solution with 94.5% purity. The main impurities have porphyrinic nature.
The absorption spectrum shows that the preparation has multiple excitation bands in visible region with most pronounced
maxima at 501 nm, 535 nm, and 556 nm, and a weak one at 606 nm. The most effective spectral range of its
electronic states excitation can serve the region of a Soret band with maximum at 404 nm. Comparative luminescent and
photosensitizing properties of Coproporphyrin III and Fotoditazin preparations have been studied. Luminescence and
singlet oxygen quantum yields have been determined to be 0.03 and 0.37 (Coproporphyrin III) and 0.05 and 0.6 (Fotoditazin)
correspondingly. A reduction of the quantum yields values at an introduction of a biological additive into aqueous
solutions of the given preparations has been found.
Preclinical trials of the preparation are performed. It is shown that Coproporphyrin III toxicity value is LD50 = 2400 ± 120 mg/kg, that allows to rank this preparation to the (V) class of almost nontoxical medicinal agents. It is shown that
the preparation Coproporphyrin III has no teratogenic and allergenic properties and does not damage erythrocytes and
thrombocytes. Absence of an influence of the preparation on the blood flow speed has been established. The results obtained
thereby testify the absence of contra-indications for clinical tests of the Coproporphyrin III preparation on indicators
of sharp toxicity.
Singlet oxygen generation by fullerene and astralen containing surfaces and powders under visible irradiation was
studied in water and organic liquids by means of 1Δg state luminescence and chemical scavenger transmittance measurements.
The chemical method, pioneered for solid photosensitizers of 102, allowed to measure the singlet oxygen concentration
in the aqueous medium down to 108 cm-3. The singlet oxygen sensitizing by the solid-phase fullerene-containing
systems was found to be 100 times less effective then by fullerene in solution. The results obtained confirm the applicability
of these structures in biology and medicine.
The results of study of sorption properties of fullerene and fullerene-like nanostructures with respect to molecular
oxygen, nitrogen and helium are given. The influence of experimental conditions (time, gas pressure, temperature and
structure of sample) on these properties is investigated.
At an irradiation of fullerenes and others fullerene-like adsorbents by light of a laser or a pulse lamp an output in a
gas phase of oxygen, adsorbed by these samples, was observed. At interaction photoexited fullerene and adsorbed
oxygen there is a transfer of excitation to oxygen and the essential part of oxygen in a gas phase was in the exited singlet
states. These effects are confirmed by experimental observation of luminescence pulses on the wavelengths 0.762 and
1.268 microns with specific pulse duration.
The processes of formation and quenching of singlet oxygen at pulse photoexcitation and photodesorption are
considered. The fullerene and fullerene-like coatings on glass, ceramic, and porous metal surfaces were investigated.
Spectral and temporary distributions of singlet oxygen luminescence for various adsorbents surfaces were studied. The
influence of adsorbents surfaces cooling of on singlet oxygen amount obtained in a gas phase and on luminescence
intensity has been investigated.
On the base of investigations of physical principles of the singlet oxygen generation during interaction of the
oxygen molecules with the solid-state photoexcited fullerenes and carbon nanostructures was proposed and realized the
prototype of the singlet oxygen generator for the fullerene-oxygen-iodine laser, working in the pulsed mode.
Studies of the dipole polarizabilities in a broad frequency range were recently reported for rare-gas atoms, in which the polarizabilities have been calculated on the basis of the modern experimental data on the differential dipole oscillator strength distributions in the resonance absorption spectra of He, Ne, Ar, Kr and Xe atoms. The calculated dynamic polarizabilities (alpha) ((omega) ) are found to be in a good agreement with the available and most reliable experimental data, the deviations being within the stated error bounds of the latter (0.1 - 0.2%). Calculations have been performed in the spectral range from the static limit up to the frequencies of the second atomic resonance transitions. Convenient analytic approximations for the (alpha) ((omega) ) functions are proposed, that are of superior accuracy compared to the commonly used three-term formulas for the polarizability dispersion.
A new spectroscopic effect of strong self-action was observed for the first time in molecular gases for vibrational transitions to combined states, in which the strongly IR active v3 mode is involved. Transformations of the v3, v1 + v3, v2 + v4 band shapes of 32SF6, 34SF6, 12CF4, 13CF4, 14NF3 upon variation of density (T equals 293 K) were studied for pure gas (p < 70 Amagat) and its dilute mixtures with Ar, Kr, Xe (pmixt < 150 Amagat). A strong linear dependence of the second spectral moment M2 on density for v3 and v1 + v3 bands in pure gases was observed, whereas no effect was found in dilute mixtures and for v2 + v4 band in pure gases.
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