Polysiloxane based on hydroxyl-containing monomer. Preparation,properties and biomedical application

Russian Chemical Bulletin - A method for synthesis of hyperbranched polysiloxane based on N-methyl-N-(2,3,4,5,6-pentahydroxyhexyl)-N’-(3-triethoxysilylpropyl)urea is proposed. In water, the...     

Novel organosilicon monomer for preparing transparent matrices doped with lanthanide complexes

Perfluoroadipic bis(trialkoxysilylpropyl)amide was synthesized as a mixture of five compounds with the general formula (EtO) _n (MeO)_3-n Si(CH₂)₃NHC(O)(CF₂)₄C(O)NH(CH₂)₃-Si(OMe) _n (OEt)_3-n (1, n = 1, 2). Hydrolysis of this product by a specified amount of water (1: 4) gave oligomers EtO[(HO)(EtO)Si(CH₂)₃NH(O)C(CF₂)₄C(O)NH(CH₂)₃Si(OEt)₂O]_nH ( _n = 7–9). From oligomer solutions, transparent glassy thermally stable films were obtained. The film material was studied by IR spectroscopy, atomic force microscopy, transmission electron microscopy, and powder X-ray diffraction. Compound 1 and oligomers can efficiently solvate lanthanide diketonate complexes. They displace water from the metal coordination sphere, and this water is then spent for hydrolysis of trialkoxysilyl groups. The luminescence intensity of matrix films based on the oligomers depends on the concentration of lanthanide complexes and is very low at 7n_exc = 330 nm, whereas the luminescence intensity of the Eu³⁺ cation is very high.     

Fluorine-containing dialkoxysilanes. The formation of complexes with aminopropyltriethoxysilane and production of transparent films

Three dialkoxysilanes with fluorine-containing groups were synthesized: methyl(3,3,3-trifluoropropyl)dimethoxysilane, methyl(3,3,3-trifluoropropyl)bis(2,2,2-trifluoroethoxy)silane, and methyl(2,2,2-trifluoro-1-trifluoromethylethoxymethyl)bis(2,2,2-trifluoro-1-trifluoro-methylethoxy)silane. It was found by IR and ²⁹Si NMR spectroscopies that (3-aminopropyl)-triethoxysilane forms complexes with the indicated compounds, which are hydrolyzed in the presence of air moisture to form films of high optical quality.     

Surface properties and structure of organofluorosilicon polymers based on organotrialkoxysilanes R<Superscript>F</Superscript>OCH<Subscript>2</Subscript>Si(OR<Superscript>F</Superscript>)<Subscript>3</Subscript>

The hydrolysis of trifunctional alkoxysilanes R^FOCH₂ Si(OR^F)₃, where R^F = CH₂CF₃, CH₂CF₂CF₃, CH₂CF₂CF₂CF₃, or CH₂CF₂CF₂CF₂CF₃, during the action of atmospheric moisture in the presence of 3-aminopropyltriethoxysilane under mild conditions yields new ladderlike polysiloxanes. Their structure is studied via ¹H NMR spectroscopy, GPC, TGA, and AFM. Polymer coatings prepared on their basis are found to be low-energy and hydrophobic. The total surface energy and polarity of the surface of polysiloxane films decrease, while their hydrophobicity increases with lengthening of the fluoroorganic substituent at the silicon atom.     

New Cyanoarylporphyrazines with High Sensitivity of Photophysical Parameters to Viscosity as Promising Agents for Photodynamic Therapy

Photophysical properties and photodynamic activity for a series of cyanoarylporphyrazine pigments have been analyzed depending on the nature of the substituents and their position in the aromatic ring. Replacement of the fluorine atom in the para-position with the methoxy group leads to significant increase in the ratio of the dark and photoinduced cytotoxicities, i.e. potential therapeutic index of porphyrazine as photosensitizer in photodynamic cancer therapy.