- Conformational analysis of 2-formylselenophene by means of 13C1H, 13C13C, and 77Se1H spinspin coupling constants
-
Theoretical energy-based conformational analysis of 2-formylselenophene performed at the MP2/6311G*level together with experimental measurements and SOPPA/aug-cc-pVTZ-J calculations of its 13C1H, 13C13C, and 77Se1H spinspin coupling constants showed that this compound predominantly adopts the s-cis conformation. Most of the spinspin coupling constants under study, especially vicinal 77Se1H couplings, demonstrate remarkable stereochemical behaviour with respect to the internal rotation of the formyl group, which is of major importance in stereochemical studies of the related selenium-containing compounds. CSIRO 2009.
- Rusakov, Yury Yu.,Krivdin, Leonid B.,Istomina, Natalia V.,Levanova, Ekaterina P.,Levkovskaya, Galina G.
-
-
Read Online
- The NMR Spectrum and Total Geometry of Selenophene Determined in the Liquid Crystal Medium ZLI 1167
-
The calculated 12C, 13C and 77Se spectra of selenophene have been reproduced from the observed proton NMR spectrum in the orienting medium Merck ZLI 1167, and the entire ring structure computed.The effects on structure of vibration, solvent dependence of couplings and temperature have been explored.Most notable was the observation of a substantial increase in the Se-C bond length, comparable to that previously reported for selenophenone in Merck Phase IV.
- Bechtold, William,Magruder, Brock G.,Goldstein, J. H.
-
-
Read Online
- Structural trends of 77Se-1H spin-spin coupling constants and conformational behavior of 2-substituted selenophenes
-
Experimental measurements and second-order polarization propagator approach (SOPPA) calculations of 77Se-1H spin-spin coupling constants together with theoretical energy-based conformational analysis in the series of 2-substituted selenophenes have been carried out. A new basis set optimized for the calculation of 77Se-1H spin-spin coupling constants has been introduced by extending the aug-cc-pVTZ-J basis for selenium. Most of the spin-spin coupling constants under study, especially vicinal 77Se-1H couplings, demonstrated a remarkable stereochemical behavior with respect to the internal rotation of the substituent in the 2-position of the selenophene ring, which is of major importance in the stereochemical studies of therelated organoselenium compounds. Copyright
- Rusakov, Yury Yu.,Krivdin, Leonid B.,Sauer, Stephan P. A.,Levanova, Ekaterina P.,Levkovskaya, Galina G.
-
experimental part
p. 44 - 52
(2010/04/06)
-
- Synthesis of selenium-derivatized nucleosides, nucleotides, phosphoramidites, triphosphates and nucleic acids
-
The present invention provides selenium derivatives of nucleosides, nucleoside phosphoramidites, nucleotides, nucleotide triphosphates, oligonucleotides, polynucleotides, and larger nucleic acids and methods for their synthesis. Selenium derivatives of both ribonucleic acids and deoxyribonulcleic acids, as well as methods for their synthesis, crystallization and uses in structural determinations, particularly by X-ray crystallographic techniques are disclosed. The selenium derivatives of the present invention are also useful as food supplements.
- -
-
-
- Synthesis, properties, oxidation, and electrochemistry of 1,2- dichalcogenins
-
Syntheses are presented of the 1,2-dichalcogenins: 1,2-dithiin, 1,2- diselenin, and 2-selenathiin, both substituted and unsubstituted. 1,2-Dithiin and 1,2-diselenin are prepared by reaction of PhCH2XNa (X = S or Se) with 1,4-bis(trimethylsilyl)-1,3-butadiyne followed by reductive cleavage and oxidation. 2-Selenathiin is similarly prepared using a mixture of PhCH2SeNa and PhCH2SNa. Reaction of titanacyclopentadienes with (SCN)2 or (SeCN)2 followed by bis(thiocyanate) or bis(selenocyanate) cyclization affords substituted 1,2-dithiins or 1,2-diselenins, respectively. With S2Cl2, 1,2- dithiins are directly formed from titanacyclopentadienes. Oxidation of 1,2- dithiins and 1,2-diselenins gives the corresponding 1-oxide and, with 1,2- dithiins and excess oxidant, 1,1-dioxides; oxidation of 2-selenathiin gives the 2-oxide. Electrochemical oxidation of 1,2-dichalcogenins, which have a twisted geometry, affords planar radical cations by an EC mechanism. One- electron AlCl3 oxidation of 3,6-diphenyl-1,2-dithiin gives the corresponding radical cation, characterized by EPR spectroscopy. Theoretical calculations result in a flattened structure for the 1,2-dithiin radical cation and a fully planar structure for the 1,2-diselenin radical cation. The 77Se NMR chemical shifts of 1,2-diselenin are characteristically high-field-shifted with respect to open chain diselenides in good agreement with results of GIAO-DFT calculations based on MP2 and DFT optimum geometries.
- Block, Eric,Birringer, Marc,Deorazio, Russell,Fabian, Juergen,Glass, Richard S.,Guo, Chuangxing,He, Chunhong,Lorance, Edward,Qian, Quangsheng,Schroeder, T. Benjamin,Shan, Zhixing,Thiruvazhi, Mohan,Wilson, George S.,Zhang, Xing
-
p. 5052 - 5064
(2007/10/03)
-
- Initiation of thermal reactions of sulfur compounds by dialkyl selenides
-
The use of diethyl selenide (20-40 mol %) as initiator in the gas-phase synthesis of thiophene from diethyl disulfide and acetylene increases the selectivity of the process and the yield of thiophene from 40 to 92%. As a result, this reaction becomes the most efficient preparative method for the synthesis of thiophene and also of selenophene which is formed in up to 70% yield. The complete conversion of both sulfur-and selenium-containing reagents is attained. Due to much different boiling points, thiophene and selenophene can readily be separated by rectification of the reaction mixture. Dialkyl selenides also initiate other thermal reactions of hydrogen sulfide and organic sulfides.
- Deryagina,Sukhomazova,Levanova,Shilkina,Korchevin
-
p. 359 - 363
(2007/10/03)
-
- Single source metalloorgranic precursors to type 14-16 semiconductors
-
The present invention relates to a single source metalloorganic precursor compound of the formula: wherein M is selected form the Group 14 elements of Germanium, Tin or Lead; A and R are independently selected from: amide, alkyl having from 1 to 20 carbon atoms, aryl, substituted aryl, or -Q'-2-NR'Ln (n=1-4) wherein L is selected from nothing or a Lewis base ligand; Q and Q' are each independently selected from Group VIa elements of sulfur, selenium, or tellurium; and 2-NR and 2-NR' are each independently selected from N-heterocyclic aryl or its derivatives. Methods of producing these compounds are also disclosed. These precursor materials provide in a single compound the binary, tertiary, or quaternary metals in a ratio to each other that is controllable by a judicious choice of metal atoms and organic substituents. The metal alloys are useful in a variety for electronic applications, particularly in semiconductors and solar energy.
- -
-
-
- HIGH-TEMPERATURE ORGANIC SYNTHESIS XLIII. REACTIONS OF ORGANIC DISELENIDES WITH PROPARGYL ALCOHOL
-
The gas-phase reaction of propargyl alcohol with dialkyl diselenides at 400 - 430 deg C leads to a high yield of 1,2-diselenol-3-one. 1,2-Diselenol-3-one is formed in a similar way from diphenyl diselenide at 450 - 500 deg C but with a low yield.The mechanism of the thermal dissociation of the diselenides and their reactions with propargyl alcohol is discussed.
- Deryagina, E. N.,Korchevin, N. A.,Voronkov, M. G.
-
p. 1069 - 1072
(2007/10/02)
-
- Free-Radical Homolytic Substitution at Selenium: An Efficient Method for the Preparation of Selenophenes
-
Substituted and unsubstituted 1-(benzylseleno)-4-iodobut-3-en-2-ols 12 and 2-(benzylseleno)-1-(2-iodophenyl)ethanols 18 react smoothly with tris(trimethylsilyl)silane in benzene at 80 deg C (AIBN initiator) to afford selenophenes 16 and benzoselenophenes 21 in excellent yield.These reactions presumably involve intramolecular homolytic substitution by aryl and vinyl radicals 14 and 20 at the selenium atom with the expulsion of benzyl radical followed by facile dehydration to afford the aromatic selenophene ring system in each case.Competitive rate studies on the ring closure of the 2-phenyl radical 25 in the presence of tri-n-butyltin hydride to give 2,3-dihydrobenzoselenophene (27) and 1-(benzylseleno)-2-phenylethane (28) provide a rate constant for ring closure (kc) of approximately 3E7 s- at 80 deg C.The determination of more accurate data is hampered by what we attribute to be the involvement of a slow, but competive nonradical process.
- Lyons, Jennifer E.,Schiesser, Carl H.,Sutej, Katarina
-
p. 5632 - 5638
(2007/10/02)
-
- Single-source metalloorganic precursors to produce II/VI materials
-
The present invention relates a precursor metal organic compound of the formula: wherein M is selected from the Group IIb elements of zinc, cadmium, or mercury; A is selected from amide, alkyl having from 1 to 10 carbon atoms, aryl, substituted aryl, or --Q'--Y'--(Si--R'3)3 L2 wherein L is selected from nothing or a Lewis base ligand, Q and Q' are each independently selected from Group VIa elements of sulfur, selenium, or tellurium; and Y and Y' are each independently selected from carbon, silicon, germanum and tin, and R and R' are each independently selected from alkyl having from 1 to 10 carbon atoms, aryl or substituted aryl. In a preferred embodiment, A is --Q'--Y'--(Si--R'3)L2 where L is nothing or a Lewis base ligand, especially wherein Q=Q', Y=Y' and R=R'. Methods of producing these compounds are also disclosed. These precursor materials provide in a single compound the binary, tertiary or quaternary metals in a ratio to each other that is controllable by judicious choise of metal atoms and organic substituents. The metal alloys are useful in a variety of electronic applications, particularly in semiconductors.
- -
-
-
- HIGH-TEMPERATURE ORGANIC SYNTHESIS XXXVI. THERMOLYSIS OF PHENYL ORGANIC CHALCOGENIDES IN THE PRESENCE OF ACETYLENE
-
Phenyl sulfides C6H5SR react with acetylene in the gas phase at 480-600 deg C with the selective formation of benzothiophene.In reaction with acetylene under analogous conditions phenyl selenides C6H5SeR (R = CH3, CH2CH2) are likewise converted into selenophene, selenophenol, and diphenyl selenide in addition to benzoselenophene (yield up to 25percent).Allyl phenyl telluride decomposes completely in the presence of acetylene even at 400 deg C, giving diphenyl telluride and diphenyl ditelluride.At 500-570 deg C the reaction products contain benzotellurophene and tellurophene (overall yield 3-4percent).
- Russavskaya, N. V.,Korchevin, N. A.,Sukhomazova, E. N.,Turchaninova, L. P.,Deryagina, E. N.,Voronkov, M. G.
-
p. 305 - 309
(2007/10/02)
-
- REACTIONS OF CHALCOGENES WITH ACETYLENES. II. REACTION OF METALLIC SELENIUM WITH ACETYLENE IN HMPTA AND DMSO
-
The effect of the conditions in the reaction of selenium with acetylene (the concentration and nature of the alkali-metal hydroxide, the temperature, the concentration of water, the addition of stannous chloride) on the yields of divinyl selenide, 2-vinyloxy-1,3-butadiene, and selenophene was investigated.It was shown that the formation of divinyl selenide under the reaction conditions is accompanied by its transformation into selenophene.
- Potapov, V. A.,Gusarova, N. K.,Amosova, S. V.,Kashik, A. S.,Trofimov, B. A.
-
p. 241 - 245
(2007/10/02)
-
- REACTIONS OF ELEMENTAL SELENIUM WITH ACETYLENES. 1. IDENTIFICATION OF THE PRODUCTS FROM THE REACTION OF ELEMENTAL SELENIUM WITH ACETYLENE
-
In the reaction of elemental selenium with acetylene at 90-115 deg C in an aqueous alkaline medium or in the HMPTA-potassium hydroxide-water and DMSO-potassium hydroxide-water systems the main direction of the reaction, leading to divinyl selenide, is accompanied by side processes leading to the formation of vinyl ethyl selenide, 1,3-di(vinylseleno)butane, 2,5-dimethyl-4-methylene-1,3-oxaselenolane, 2-vinylseleno-1-buten-3-ol, cis-1-vinylseleno-1-buten-3-ol, cis,cis-di(3-hydroxy-1-butenyl)selenide, and also selenophene and 2-vinyloxy-1,3-butadiene.
- Gusarova, N. K.,Trofimov, B. A.,Potapov, V. A.,Amosova, S. V.,Sinegovskaya, L. M.
-
p. 436 - 441
(2007/10/02)
-
- REACTIONS OF TRIADS S8-KOH-DMSO, Se8-KOH-DMSO, Te-KOH-HMPA WITH ACETYLENES
-
A new general approach to anionic transformations of acetylenes using superbasic media has been developed.It allows series of new reactions which are not undergone by acetylene under conventional conditions.The triads S8-KOH-dimethylsulfoxide (DMSO), Se8-KOH-DMSO, Te-KOH-hexamethyl-phosphorictriamide (HMPA) are proposed as new effective reagents for the preparation of unsaturated compounds of sulfur, selenium and tellurium.A series of reactions of acetylene with sulfur, selenium and tellurium proceeding in DMSO or HMPA in the presence of alkali and water at 80-120 deg C leading to divinyl sulfide, divinyl selenide and divinyl telluride in 25-80percent yields have been found.Thiophen, di-1-(1,3-butadienyl) sulfide, 1-vinyl-2-thiabicyclohept-3-ene, and dihydrothiophen have been obtained by the reaction of vinylacetylene with sulfur.The reaction of vinylacetylene with selenium affords selenophen, di-1-(1,3-butadienyl) selenide, 1-vinyl-2-selenabicyclohept-3-ene, methyl (1-(1,3-butadienyl) sulfide, and methylthiomethyl 1-(1,3-butadienyl) selenide, vinyl 1-(1,3-butadienyl) sulfide and methylthiomethyl 1-(1,3-butadienyl) selenide (the latter two with DMSO participation).The reaction of vinylacetylene with tellurium gives mainly di-1-(1,3-butadienyl) telluride.A series of reactions between DMSO and selenium leading to dimethyl sulfide, dimethyl sulfoselenide, and methylthiomethyl selenide have been observed.
- Trofimov, B. A.,Amosova, S. V.,Gusarova, N. K.,Musorin, G. K.
-
p. 713 - 718
(2007/10/02)
-
- REACTION OF VINYLACETYLENE WITH ELEMENTAL SELENIUM. SYNTHESIS OF SELENOPHENE, DI(1,3-BUTADIENYL) SELENIDE, AND 1-VINYL-2-SELENABICYCLOHEPT-3-ENE
-
In reaction with selenium dianion, generated from elemental selenium (Se8), in the dimethyl sulfoxide - potassium hydroxide - water system at 100 - 200 deg C vinylacetylene gives selenophene, di(1,3-butadienyl) selenide, and 1-vinyl-2-selenabicyclohept-3-ene.The reaction mixture also contained methyl 1,3-butadienyl sulfide and methylthiomethyl 1,3-butadienyl selenide, which are the products from reaction of vinylacetylene, dimethyl sulfoxide, and selenium in the presence of the base.
- Trofimov, B. A.,Musorin, G. K.,Kalabin, G. A.,Amosova, S. V.
-
p. 448 - 453
(2007/10/02)
-
