Synthesis and photochemical properties of the indoline series fulgides

Using the Stobbe condensation fulgides that undergo E, Z-isomerization on exposure to UV radiation are obtained from diethyl [2-(1,3,3-trimethyindoline-2-ilidene)ethylidene]succinate, and benzaldehyde and its derivatives; and from 1,2-dimethyl-3-formylindole and -formyl-1,3,3-trimethyl-2-methyleneindoline. The structure and photochemical changes of the fulgides were investigated by means of PMR.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 55–60, January, 1992.     

Synthesis, structures, and photochromic properties of N-aryl-3-indolylfulgides

New 3-indolylfulgides, viz., 3-[1-(1-aryl-5-methoxy-2-methyl-1H-indol-3-yl)ethylidene]-4-(1-methylethylidene)tetrahydro-2,5-furandiones, were synthesized. These compounds were obtained as E-isomers, as demonstrated by X-ray diffraction, electronic spectroscopy, and ¹H NMR spectroscopy. Fulgides exhibit photochromic properties in solution. The cyclic dihydrocarbazole photoisomers of indolylfulgides show fluorescence properties and are characterized by high thermal stability. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1417–1423, July, 2008.     

Effect of the type of linkage between phenyl groups on the structure and photochemical properties of 2,2-diaryl-substituted pyridoannelated [2H]-chromenes

Three 2,2-diaryl-substituted pyridoannelated [2H]-chromenes have been studied by X-ray diffraction analysis. Bonding of the benzene rings through bridges of different nature and with different length affects substantially the orientation of the benzene rings, steric interactions at the C center, the conformation of the molecule, and the C−O bond length. A correlation between the photocolorability of chromenes under study and the orientation of the benzene rings with respect to the C−O bond, which provides different prerequisites to stabilization of the C(1)-centered, cation formed upon cleavage of the C−O bond, was established. The effect of the orientation of the benzene rings on the dark reaction of ring closure was found. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1129–1135, June, 1998.     

Synthesis and structure of indoline spiropyrans of the coumarin series

New indoline spiropyrans of the coumarin series were synthesized by the condensation of indoline and hydroxyformylcoumarin derivatives. Spiropyrans, viz., derivatives of 8-formyl-7-hydroxy-4-methylcoumarin and 5-formyl-6-hydroxy-4-methylcoumarin, under irradiation are transformed into open forms, which are recyclized in the dark. The compounds formed by the condensation of the indoline derivatives with 3-formyl-4-hydroxycoumarin have an open structure of the merocyanine dyes and are transformed into spiro forms neither in the dark nor under irradiation with the visible light. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2342–2349, October, 2005.     

Synthesis,crystal structure,vibrational and dielectric properties of di-benzyl-ammonium selenite monohydrate

The new hybrid compound [C₆H₅CH₂NH₃]_2·SeO_3·H₂O was synthesized and found to crystallize in the triclinic space group P$\overline{1}$. This structure can be described as an alternation between organic and inorganic chains connected by two types of N−HO and O−HO hydrogen bonds. The two and antiparallel cations [C₆H₅CH₂NH₃]⁺are arranged in a face-to-face pattern with a distance of 3.911(10)Å between them, indicating the existence of π-π interaction. The thermal properties show that the mass losses take place in three steps, which correspond to dehydration and degradation of the title compound. The IR and Raman spectra prove the existence and independence of the organic and inorganic groups as well as a water molecule. The equivalent circuit is modeled by a combination series of two parallel R–CPE circuits. Dielectric studies show that this material is ionic-protonic conductor at low temperature and becomes electronic one at high temperature.     

Synthesis,structure, and thermal properties of fluorinated cesium beta-diketonates

Four fluorinated cesium beta-diketonates, Cs(CF₃COCHCOCF₃) (Cs(hfac)), Cs(CF₃COCHCOCH₃) (Cs(tfac)), Cs(OH₂)((Me)₃CCOCHCOCF₃) (Cs(OH₂)(ptac)), and Cs(OH₂)(PhCOCHCOCF₃) (Cs(OH₂)(btfac)), were synthesized by interaction of the corresponding beta-diketone and Cs₂CO₃ in Et₂O. The formation of Сs(CF₃C(OH)₂CH₂C(OH)₂CF₃)(CF₃COO) or Cs(CF₃C(OH)₂CH₂COCH₃)(tfac) was shown to be dependent on the reaction conditions. The compounds were characterized by elemental analysis, single crystal X-ray diffraction, and TG/DTA analysis. All compounds have ionic structures organized into pseudo chains (in the case of Cs(hfac) and Cs(CF₃C(OH)₂CH₂COCH₃)(tfac)) or pseudo layers (in other cases). According to the TG data Cs(hfac), Cs(tfac), Cs(OH₂)(ptac,) and Cs(OH₂)(btfac) decompose in inert atmosphere within the temperature range 30–550?°C.     

Synthesis,crystal structure and spectral characterization of Co(II) complexes with acylpyrazolone ligands

The three new Cobalt(II) complexes [Co(L¹)₂(H₂O)₂] (1), [Co(L²)₂(H₂O)₂] (2), and [Co(L³)₂(H₂O)₂] (3) have been synthesized by interaction of acyl pyrazolone ligands, 4-(4-chlorobenzoyl)3-methyl1-phenyl1H-pyrazole5(4H)-one (HL¹), 4-(4-chlorobenzoyl)1-(3-chlorophenyl)3-methyl1H-pyrazole5(4H)-one (HL²) and 5-methyl4-(4-methylbenzoyl)2-phenyl2,4-dihydro3H-pyrazole3-one (HL³) with CoCl₂.6H₂O. The complexes were screened using FTIR, UV–Vis, TGA, and Single Crystal X-ray diffraction spectroscopic techniques. A relative study of the ligands’ FTIR spectra and their metal complexes reveal the formation, sifting, and disappearance of several bands during complexation. Other interpretations stipulated that these three complexes are mononuclear and exhibited octahedral geometry around Co²⁺.Triclinic crystal system, Distortion in Octahedral geometry, and Intermolecular hydrogen bonding confirmed by Single-crystal XRD analysis of [Co(L³)₂(EtOH)₂] complex.     

Synthesis, properties, and the crystal structure of the complex Cp2Yb(DAD)

The diazadiene complex of trivalent ytterbium, Cp₂Yb(DAD) (1) (DAD=Bu^t−N=CH−CH=N−Bu^t) was prepared according to three different procedures, namely, by oxidation of Cp₂Yb(THF)₂ with diazadiene in THF, by the reaction of Cp₂YbCl with DAD²⁻Na⁺ ₂ taken in a ratio of 2∶1, and by the reaction of Cp₂YbCl(THF) with DAD²⁻Na⁺ ₂ taken in a ratio of 1∶1. Complex1 was characterized by microanalysis, IR spectroscopy, magnetochemistry, and X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 384–386, February, 1999.     

Synthesis, characterisation and anion exchange properties of copper, magnesium, zinc and nickel hydroxy nitrates

Anion exchange reactions of four structurally related hydroxy salts, Cu₂(OH)₃NO₃, Mg₂(OH)₃NO₃, Ni₂(OH)₃NO₃ and Zn₃(OH)₄(NO₃)₂ are compared and trends rationalised in terms of the strength of the covalent bond between the nitrate group and the matrix cation. Powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and elemental analysis are used to characterise the materials. Replacement of the nitrate anions in the zinc and copper salts with benzoate anions is possible although exchange of the zinc salt is accompanied by modification of the layer structure from one where zinc is exclusively six-fold coordinated to a structure where there is both six- and four-fold zinc coordination. Magnesium and nickel hydroxy nitrates, on the other hand, hydrolyse to their respective metal hydroxides.     

Synthesis, crystal structure and magnetic properties of an alternating manganese chain

A new 1D complex has been prepared and characterized. X-ray single crystal structure confirms that the Mn(II) ions assemble in alternating chains with Mn-Mn distances of 3.8432(13) and 4.4428(14) Å. A 3D network of hydrogen bonds links the chains together. The temperature dependence of the magnetic susceptibility reveals that this compound undergoes a magnetic transition and exhibits an antiferromagnetic interaction in the low-temperature phase with two alternating exchange interactions of −2.32(1) and −5.55(1) cm⁻¹.     

Synthesis,structure and chemical properties of hypervalent germanium compounds,derivatives of lactams with a fragment

The results of studies aimed at elaborating methods for synthesizing penta- and hexacoordinated organogermanium derivatives containing lactamo-N-methyl and related bidentate ligands and investigating their structure and reactivity are reviewed. In these compounds the germanium coordination units include one or two O(or S)-Ge-X or N-Ge-X (X — an electron-deficient group) hypervalent fragments.The review is based on the report at the conference Workshop on the Modern Problems of Heteroorganic Chemistry, Moscow, May 8–13, 1993.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 982–993, June, 1994.     

Alstobrogaline,an unusual pentacyclic monoterpenoid indole alkaloid with aldimine and aldimine-N-oxide moieties from Alstonia scholaris

Alstobrogaline (1), an unusual monoterpenoid indole alkaloid incorporating a third N atom and possessing two aldimine functions, with one being in the form of N-oxide, was isolated from the leaves of Alstonia scholaris. Its structure and relative configuration were determined by extensive NMR spectroscopic analysis, while its absolute configuration was established by X-ray diffraction analysis. A possible biogenetic pathway to 1 was proposed. Compound 1 displayed weak cytotoxic effects against MDA-MB-231 and MCF7 breast cancer cells.     

Synthesis, structure, and electrochemical properties of biferrocenes annulated with 1,2-dithiin and 1,2-dithiin 1,1-dioxides

2,2″-Bis(N,N-dimethylaminosulfonyl)-1,1″-biferrocene (6), a precursor of biferrocenes annulated with 1,2-dithiin and 1,2-dithiin 1,1-dioxides, was prepared by a sequence of selective ortho-lithiation and dimerization reaction from N,N-dimethylaminosulfonylferrocene. New biferrocenes annulated with 1,2-dithiin (1) and 1,2-dithiin 1,1-dioxides (2) and (3) were successfully synthesized in satisfactory yields by the reaction of compound 6 with lithium aluminum hydride followed by treatment with chlorotrimethylsilane. The electrochemical properties of the biferrocenes (1)-(3) were furnished by voltammetric studies.     

Photochemistry of macromolecular metal complexes. III. Synthesis,spectral and electrochemical properties of macromolecular bound protoporphyrin in aqueous solution

The macromolecular bound protoporphyrin IX and its metal complexes, poly-(protoporphyrin-co-acrylamide), cobalt(II) [poly(protoporphyrin-co-acrylamide)], zinc-(II)[poly(protoporphyrin-co-acrylamide)], and manganese(III) [poly(protoporphyrin-co-acrylamide)] chloride were synthesized. The absorption and emission spectra have been obtained for the macromolecular porphyrins. The lifetime of the excited singlet state of the protoporphyrin IX was found to decrease from 13.7 to 6.2 ns after polymerization. The cyclic voltammograms of polymeric protoporphyrin coated electrodes have been obtained. © 1992 John Wiley & Sons, Inc.     

Synthesis,structure, and complexation properties of tetraamide derivatives of thiacalix[4]arene in different conformations

The interaction of p-tert-butylthiacalix[4]arene with N,N-diethylchloroacetamide was studied in the presence of alkali metal carbonates in acetone. Three stereoisomers, viz., cone, partial cone, and 1,3-alternate, of the tetraamide derivative of thiacalixarene substituted at the lower rim were synthesized selectively using the template effect of alkali metal cations, as well as a complex of the 1,3-alternate stereoisomer with potassium chloride. The structures of the compounds synthesized were studied by 2D NMR spectroscopy. A high extraction ability of the compounds toward alkali metal cations was demonstrated. Dedicated to Academician A. L. Buchachenko on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2041–2049, September, 2005.     

Synthesis,structure, and characterization of Cu4S10(4-methylpyridine)4

The title compound, Cu₄S₁₀(4-methylpyridine)₄ · 4-methylpyridine was prepared by three different reactions: the oxidation of copper power by sulfur and the reaction of copper (I) sulfide (or CuBr-SMe₂) with cues sulfur, both in the coordinating solvent, 4-methylpyridine. Red crystals of the compound obtained by layering with hexans were subjected to single crystal X-ray diffraction. The structure was refined toR=0.026 and R _w =0.036 in a space groupP1bar (No. 2), withZ=2,a=13.983 (2) A,b=15.384( 2) Å,c=9.660 (1) Å, = 93.87 (1)°,=93.38 ==(1)°,V=2037.9 (9) ų. The commpound has approximate S₄ symmetry and consists of two pentasuffide chains linking four Cu(I) ions, each with a coordinating 2-methylpyridine. The infrared spectrum was dominated by absorption due to coodinated 4-methylpyridine with several low-energy peaks attributable to S-S stretches, which were also observed by Raman spectroscopy. A featureless electronic absorption spectrum yielded a single peak in the mar ultraviolet upon computer enhancement (=334 nm, = 10,000), most likely an intraligand transition. Cyclic voltammetry indicates that the polysulfide complex undergoes irreversible oxidation and reduction at +0.04 and –0.34 V vs. SCR respectively, at NS K in 4-methylpyridine when swept at 20 mV/sec. The electrochemical behavior was unvaried even at sweep rates as high as 100 V/sec.     

Synthesis,structures, and selected chemical properties of 2-chloro- and 2-bromo-1,1-diferrocenylcyclopropanes

2-Chloro- and 2-bromo-1,1-diferrocenylcyclopropanes were synthesized as Z- and E-isomers with respect to the ferrocenyl substituent having a bisector orientation. The structure of Z-2-chloro-1,1-diferrocenylcyclopropane was confirmed by X-ray diffraction analysis. Treatment of the resulting monohalides with potassium tert-butoxide in dimethyl sulfoxide afforded 3,3-diferrocenylcyclopropene in 20% yield. The small ring in halogen-substituted diferrocenylcyclopropanes and diferrocenylcyclopropene is readily cleaved to give predominantly 3-ferrocenyl-1H-cyclopentaferrocene.