Metal Complexes of 2,9,16,23-Tetra- tert -butyl-3,10,17,24-tetranitrophthalocyanine with Lanthanides

Metallization of 2,9,16,23-tetra-tert-butyl-3,10,17,24-tetranitrophthalocyanine or template condensation of 4-tert-butyl-5-nitrophthalodinitrile with chlorides of some lanthanides furnished the corresponding metal complexes. Their spectral properties were studied.     

Adsorption properties of the MOF-5 metal-organic framework in relation to water and benzene

Adsorption properties of synthesized metal-organic frameworks based on 1,4-dicarboxylate ligands and zinc ions were studied. It was shown that the adsorption properties of these metal-organic frameworks in relation to water and benzene are much higher than those for the known adsorbents: KT-1 and KT-2 coals, USY and ZSM-5 zeolites, and pentasil.     

Chemical transformations of lanthanide nitrate complexes: Synthesis and X-ray diffraction analysis

The complexes [Dy(NO₃)₃(Bipy)₂], (HBipy)[Gd(NO₃)₄(Bipy)], and [Fe^III(Me₂Bipy)₃][La(NO₃)₅(H₂O)]NO₃ and the precursor of the latter, [Fe^IIPc₂(Me₂Bipy)](CHCl₃) · 1.5H₂O (where Bipy is the 2,2′-bipyridyl, Me₂Bipy is the 4,4′-dimethyl-2,2′-bipyridyl, and Pc^? is the pyridine-2-carboxylate anion), were obtained and characterized by X-ray diffraction analysis. Depending on the conditions of the synthesis and the reagents, the number of coordinated nitrate groups in the lanthanide complex increases from three to five: [Dy(NO₃)₃(Bipy)₂], [Gd(NO₃)₄(Bipy)]^?, and [La(NO₃)₅(H₂O)]^2?.     

Synthesis,structures and biological properties of nickel(II) phthalates with imidazole and its derivatives

Four new nickel(II) phthalate compounds: mononuclear complexes [Ni(Im)]₆(Pht)·H₂O (1), [Ni(Pht)(Im)₃(H₂O)₂]·H₂O (2) and [Ni(Pht)(2-MeIm)₃(H₂O)₃]·H₂O (3), and coordination polymer [Ni(Pht)(4-MeIm)₂(H₂O)]_n (4) (where Pht = dianion of o-phthalic acid, Im = imidazole, 2-MeIm = 2-methylimidazole, 4-MeIm = 4-methylimidazole) have been synthesized. The complexes 1–4 were characterised by elemental analysis, IR data, thermogravimetric, and X-ray diffraction analyses. X-ray analysis shows that the asymmetric unit of 1 consists of [Ni(Im)]₆²⁺ cation, Pht²⁻ anion and solvate H₂O molecule. The phthalate dianion does not take part in coordination to metal ion. The cations, anions and water molecules are linked via   N–H?$?$O and O–H?$?$O interactions forming 2D hydrogen-bonded networks. The structures of 2 and 3 are similar to other mononuclear Ni(II) phthalate complexes where Pht²⁻ anions act as monodentate ligands and uncoordinated carboxylate oxygen atoms participate in the formation of hydrogen bonded double-chains. The structure of 4 consists of [Ni(4-MeIm)₂(H₂O)] building units connected by phthalate ions to form helical chains. The complexes 1–4 were tested for their ability to increase the biosynthesis of enzymes.     

Alkylation of 4(5)-nitro-1,2,3-triazole with alcohols in strongly acidic media

Alkylation of 4(5)-nitro-1,2,3-triazole with alcohols in concentrated H₂SO₄ occurs at all three endocyclic N atoms, giving a mixture of isomeric N(1)-, N(2)-, and N(3)-alkyl-4-nitro-1,2,3-triazoles (alkyl is isopropyl, sec-butyl, and cyclohexyl). The selectivity of the alkylation depends on the alcohol used. The most selective alkylation is provided at the N(2) atom when isopropyl (81%) and sec-butyl alcohols are used (67%). With an increase in the reaction time, also in the order isopropyl-, sec-butyl-, and cyclohexyl-4-nitro-1,2,3-triazoles, the N(2)-isomers undergo isomerization into N(1)-alkyl-4-nitro-1,2,3-triazoles. In all the cases, the fraction of the N(3)-substitution products in the mixtures is 6–30%.     

Direct photolysis of chlorophenols in aqueous solutions by UV radiation from excilamps

Direct photolysis of 2- and 4-chlorophenol and 2,4-dichlorophenol in aqueous solutions by UV radiation from XeBr (282 nm) and KrCl (222 nm) excilamps at various pH values was subjected to a comparative study.     

Identification of bromination products of chloro-substituted anilines in aqueous environment by gas chromatography

To reduce the detection limits of aniline and its various chloroderivatives (all isomers of mono- and dichloroanilines, 2,4,5 -, 2,4,6-, and 3,4,5-trichloroanilines, pentachloroaniline) in aqueous media we suggested bromination reaction, followed by gas chromatographic definition bromo derivatives of chloroanilines on a selective electron capture detector. To identify the products of bromination of chloroaniline in combination with mass-spectrometric data we used chromatographic retention indices on standard nonpolar polydimethylsiloxane stationary phase that was determined for 50 compounds in this class. The technique of identifying bromoderivatives of chloroaniline in water was developed at the gas-chromatographic analysis in the selective electron capture detector. To improve the reliability of the identification of additional bromoderivatives of chloroanilines we obtained their trifluoroacetyl derivatives.     

Possibilities of Microporous and Hierarchical MFI Zeolites in the Synthesis of Nitrogen Heterocyclic Compounds

Kinetics and Catalysis - The catalytic properties of a microporous H-ZSM-5 zeolite and a granular hierarchical H-ZSM-5h zeolite in the synthesis of basic pyridines and quinolines have been studied....     

Homogeneous sound-absorbing structures for aircraft engine ducts

As applied to the ducts of aircraft engines, a new method is studied for extending the frequency range of sound absorption by using special homogeneous materials of a rigid structure. A through- or blind-hole perforation of such a homogeneous material is for the first time suggested with a view to substantially extend its capabilities. A theory is developed for sound-absorbing structures of perforated homogeneous material that allows for computing their wave parameters and impedance on the basis of those of the starting material. Based on this theory, one can calculate the impedance of any, no matter how complex a structure built up of several layers differing in thickness and perforation percentage and diameter. The results of calculations made for the impedance and sound absorption coefficient of single and multiple layer samples show good agreement with experimental data.