Chalcogen Halides Research Articles

A Regioselective Synthesis of Novel Functionalized Organochalcogen Compounds by Chalcogenocyclofunctionalization Reactions Based on Chalcogen Halides and Natural Products.

The regioselective synthesis of novel functionalized condensed organochalcogen compounds by chalcogenocyclofunctionalization reactions based on chalcogen halides and the natural products thymol and carvacrol has been developed. The reactions of selenium dibromide with allyl thymol and allyl carvacrol proceeded in methylene chloride at room temperature in the presence of NaHCO3 affording bis[(7-isopropyl-4-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] and bis[(4-isopropyl-7-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] selenides in 90–92% yield. Similar sulfides were obtained in 70–72% yields by the reaction of sulfur dichloride in chloroform under reflux. Trihalotellanes containing the same organic moieties were synthesized from allyl thymol, allyl carvacrol and tellurium tetrachloride or tetrabromide in quantitative yields. Corresponding functionalized ditellurides were prepared in 91–92% yields by the reduction of the trichlorotellanes with sodium metabisulfite in two-phase solvent system. The comparison of reactivity of sulfur, selenium and tellurium halides in chalcogenocyclofunctionalization and distinguishing features of each reaction were discussed.

TO THE 70th ANNIVERSARY OF VASYL LENDEL

Vasyl Lendel was born on December 3, 1949 in the Volovets of Transcarpathian region. He has completed secondary education in Svalyava, graduating with honors Svalyava Polytechnic College in 1968. He has continued studies at the Faculty of Chemistry of Uzhhorod State University. He has graduated with honors in higher education in 1973.V.G. Lendel started his work via teaching chemistry at the Svalyava Polytechnic College, and in October 1973 he was invited to take the position of engineer of the Department of Organic Chemistry at UzhSU. In 1974-1977 he studied in graduate school at this department under the supervision of Professor Mygalin Yu.V. In 1977 he has become a head of the laboratories of the Department of Organic Chemistry of Uzhgorod State University.In June 1996, Vasyl Lendel heads the scientific-pedagogical staff of the Department of Organic Chemistry and is appointed to the position of the Dean of the Faculty of Chemistry of Uzh-horod State University, which he holds to this day.V.G. Lendel defends his thesis "Reactions of attachment of selenium tetrahalogens to 1,6-, 1,5-, 1,4-diolefins and their derivatives and properties of adducts obtained" and obtains the degree of candidate of chemical sciences in Taras Shevchenko State University of Kyiv in 1981. Later in 1982 he was elected to the position of assistant of the Department of Organic Chemistry, and in 1985 – Associate Professor of the Department of Organic Chemistry of Uzhhorod State University. He was conferred the academic title of Associate Professor in April 1987. For the cycle of scientific works in 2007 V.G. Lendel was awarded the degree of Doctor of Chemical Sciences.V.G. Lendel is a highly qualified specialist in the field of organic and element-organic chemistry. He heads a scientific school that studies the synthesis, chemical, physical, and biological properties of chalcogen-containing heterocyclic compounds. V.G. Lendel is studying the regio- and stereo-chemistry of electrophilic intra-molecular cyclization of unsaturated acyclic and heterocyclic compounds under the action of such electrophilic reagents as halogens, chalcogen halides. There are three defended PhD theses under his supervision; he fulfilled state budget grants and contractual grants, including foreign scientific projects. He has 624 scientific and teaching works, including about 400 publications in professional scientific journals, of which more than 50 publications are in journals included in science-metric databases. A large number of copyright author certificates and patents testify to the practical importance of his scientific research.He has been awarded the honorary title of "Excellence in Education of Ukraine", "Honored Worker of Higher Education", "Inventor of the USSR", "Honored Worker of Education of Ukraine" for his considerable achievements in work, high professionalism, personal contribution to the development of Ukraine and Transcarpathia. For his merits in scientific and pedagogical work he was awarded the Distinction of President of Ukraine, "Acknowledgment of the President of Ukraine", Anniversary Medal on the occasion of "10th Anniversary of Independence of Ukraine", Honorary Certificate of the Verkhovna Rada of Ukraine, Honorary Certificate of the NAS of Ukraine, Honorary Certificate of the MES of Ukraine, Silver Anniversary Order of the Ukrainian Technological Academy, For Merit industry and art”, the honors and thanks of the Transcarpathian Regional State Administration.

Insights into the formation of inorganic heterocycles via cyclocondensation of primary amines with group 15 and 16 halides.

Cyclocondensation is a major preparative route for the generation of inorganic heterocycles especially in the case of ring systems involving a Group 15 or 16 element linked to nitrogen. This Perspective will consider recent experimental and computational studies involving the reactions of primary amines (or their synthetic equivalents) with pnictogen and chalcogen halides. The major focus will be a discussion of the identity and role of acyclic intermediates in the reaction pathways to ring formation, as well as the nature of the heterocycles so formed. The similarities and differences between the chemistry of group 15 and 16 systems are emphasised with a view to providing signposts for further investigations.

Recent Advances in Organochalcogen Synthesis Based on Reactions of Chalcogen Halides with Alkynes and Alkenes

Recent Advances in Organochalcogen Synthesis Based on Reactions of Chalcogen Halides with Alkynes and Alkenes

One-pot synthesis of unsymmetrical divinyltellane from TeCl4, phenylacetylene, and 1-hexyne

Organotellurium compounds containing a vinyl group are important semiproducts for organic synthesis [1]. These compounds can be obtained both by the nucleophilic addition of telluride anions to a triple bond [1, 2] and by the addition of tellurium halides to alkynes [1, 3, 4]. The addition of tellurium tetrahalides to alkynes leads to the formation of trihalo(2-halovinyl)tellanes or to (Z)or (Е)-dihalo[bis(2-halovinyl)]tellanes depending on the reaction conditions and the reagents ratio [1, 3, 4]. Presumably the monoadducts may be used in the addition reaction to another alkyne, but the information on the synthesis of unsymmetrical divinyltellanes from tellurium tetrahalides and two different alkynes is absent from the literature. In continuation of our systematic research on the addition of chalcogen halides [4, 5] to unsaturated compounds we performed a one-pot regioand stereoselective synthesis of an unsymmetrical divinyltellane from TeCl4 and two different alkynes. Dichloro[(Z)-(2-chlorohex-1-enyl)(Z)-(2-phenyl-2-chlorovinyl)]tellane (II) was obtained in 95% yield in two stages from TeCl4, phenylacetylene, and 1-hexyne. The reaction between TeCl4 and phenylacetylene proceeded selectively at boiling equimolar amounts of reagents in a mixture of solvents СС14–C6H6, 9 : 1 with the formation of trichloro-(Z)-(2-phenyl-2-chlorovinyl) tellane (I) in a nearly quantitative yield. Then to the reaction mixture solution of 1-hexyne in benzene was added. The regioand stereoselective addition of tellane I to 1-hexyne occurred at boiling the reagents in the mixture of solvents ССl4–C6H6, 1 : 1, affording a previously unknown dichloro[(Z)-(2-chlorohex-1-enyl)-(Z)-(2-phenyl2-chlorovinyl)]tellane (II) in an overall yield 95%. Structure, confi guration, and composition of compound II were established with the help of 1H, 13C NMR, in particular, NOESY, spectra, and the elemental analysis data. The synthesis of monoadduct I from phenylacetylene and ТеСl4 was described in [3].

ChemInform Abstract: Reaction of Bis(prop‐2‐yn‐1‐yl) Sulfide with Sulfur Dichloride. First Example of Cyclization of Bis(prop‐2‐yn‐1‐yl) Chalcogenides by the Action of Chalcogen Halides.

Abstract(E,E)‐2,6‐Bis(chloromethylidene)‐1,4‐dithiane (II) is regio‐ and stereoselectively obtained in an anti‐Markovnikov addition at both triple bonds of compound (I).

Reactions of Diiminopyridine Ligands with Chalcogen Halides

The reactions of the chalcogen halides (Ch = S, Se, Te) with a series of diiminopyridine (DIMPY) ligands were explored. It was determined through these studies that varying both the substitution on the α-carbon and the chalcogen halide reagent afforded different products. If methyl groups were present on the α-carbon, reactivity was observed through the eneamine tautomer to yield N,N',C-bound neutral chalcogen complexes. In the cases where H and C(6)H(5) groups were in the same position, N,N',N″-chelated chalcogen cations or dications were produced. Many of the reactions resulted in complex mixtures postulated to occur by the release of halogen decomposing the product or, for reactions with the CH(3) substituted ligand, uncontrollable reactivity with the eneamine tautomer. This is the first report of reactions of sulfur and selenium halides with the ubiquitous diiminopyridine ligands and only the second example for a tellurium halide.

Reaction of bis(prop-2-yn-1-yl) sulfide with sulfur dichloride. First example of cyclization of bis(prop-2-yn-1-yl) chalcogenides by the action of chalcogen halides

(E,E)-2,6-Bis(chloromethylidene)-1,4-dithiane (II) is regio- and stereoselectively obtained in an anti-Markovnikov addition at both triple bonds of compound (I).

Catalytic perfomance of rhodium chalcogen halides and rhodium chalcogenides over silica supports in methane oxidative carbonylation

The gas phase methane oxidative carbonylation was studied in the presence of molecular oxygen over silica materials including their mechanical mixtures with rhodium chalcogen chlorides obtained in non-aqueous inorganic media. The formation of Rh 4SCl 7, Rh 4S 9Cl 2, Rh 4Se 5Cl 3 and Rh 3Se 3Cl solids was confirmed by elemental analysis, IR absorption spectroscopy, XPS and X-ray diffraction. Silica, vanadium-, and molybdenum-containing mesoporous molecular sieves have been used as supports. It was found that productivity of oxygenates (methanol, methyl acetate and acetic acid) depends mainly on the method of the catalyst preparation and the type of the support.

A comparison between polar covalent bonding and hypervalent recoupled pair bonding in diatomic chalcogen halide species {O,S,Se} × {F,Cl,Br}

The 2Π ground states and low-lying 4Σ– excited states of the nine diatomic species formed by combining O, S, or Se with F, Cl, or Br were characterized with multireference configuration interaction calculations in order to compare and contrast the behaviour of the bonding in these two states of the chalcogen halides. For each of these species, the 2Π ground state is polar covalently bound via simple singlet coupling of unpaired electrons on each atom. But for each compound there is also a bound 4Σ– state where bond formation requires recoupling the valence p 2 pair of electrons on the chalcogen atom. This mode of bonding makes more electrons available for additional bond formation and is the basis of hypercoordination. The behaviour of S and Se differs significantly from that of O. Although the hypervalent 4Σ– states of the diatomic chalcogen halides are bound for all three elements, the O species are only weakly bound and exhibit minimal recoupling compared with the corresponding S and Se compounds.

Synthesis of N,C Bound Sulfur, Selenium, and Tellurium Heterocycles via the Reaction of Chalcogen Halides with −CH3 Substituted Diazabutadiene Ligands

A series of N,C bound chalcogen heterocycles from the reaction of chalcogen halides (ChX(n); Ch = S, Se Te; X = Cl, Br; n = 2, 4) with N-alkyl or N-aryl 1,4-diazabutadiene (DAB) ligands featuring methyl substituents on the backbone C-C linkage are reported. In contrast to what is observed for other p-block elements with the same ligand systems, which typically bind in an N,N' fashion, the chalcogens react with the ligand in an unusual manner, forming N(1)C(3)Ch(1) five-membered rings by incorporating a "backbone" methyl group. Solid state structures of the feature compounds have been confirmed by X-ray crystallographic studies. The reaction mechanism was probed by deuterium isotope labeling of the DAB ligand and analyzed using stopped-flow kinetics experiments, which supported attack by the olefin in the enamine form of the DAB ligand with concomitant loss of HX.

Methane oxidative carbonylation catalyzed by rhodium chalcogen halides over carbon supports

Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carbon supports. XPS and IR-spectroscopy data show the formation of rhodium chalcogen halides in solids prepared by different methods. We have found that the productivity of acetic acid by carbon supported rhodium chalcogen halides depends strongly on the carbon carrier and the method of the catalyst preparation. Namely, the catalyst with highest productivity for the acetic acid is prepared by synthesizing the rhodium chalcogen halide over the carbon support followed by thermal destruction. We have also found that rhodium chalcogen halides over activated carbons are more active compared with fullerene supported catalysts.

Synthesis and characterization of cationic selenium–nitrogen heterocycles from tert-butyl-DAB (DAB = 1,4-di-tert-butyl-1,3-diazabutadiene) and SeX4via the reductive elimination of X2 (X = Cl, Br): a distinct contrast with tellurium

The synthesis and comprehensive characterisation of a series of 1,2,5-selenadiazolium salts, which were generated from the direct reaction between the neutral bidentate ligand tert-butyl-DAB and a variety of heavy chalcogen halides, are reported. The formation of the cationic heterocycle from the reaction of SeX4 (X = Cl, Br) and the ligand results in a two electron redox process where the chalcogen undergoes a two electron reduction concomitant with the elimination of X2, the oxidation by-product. A reaction pathway for this chemistry has been proposed necessitating several key intermediates. These species have been synthesized and used in a stepwise series of transformations that strongly supports this very unusual reactivity for the chalcogens. In contrast, the reaction between tert-butyl DAB and TeX4 (X = Cl, Br, I), does not result in redox, rather an octahedral Te(iv) x DAB complex is formed or no reaction was observed.

Ag10Te4Br3: A New Silver(I) (poly)Chalcogenide Halide Solid Electrolyte

Ag10Te4Br3 is the first representative of an M(group 11) (poly)chalcogenide halide with covalently bonded [Te2]2- units and isolated Te2- ions. It represents a new class of materials located between M(group 11) chalcogen halides, characterized by covalently bonded chalcogen structure motives, on the one hand and chalcogenide halides, consisting of isolated chalcogenide ions, on the other. A high silver mobility on distinct silver layers was observed for orthorhombic Ag10Te4Br3, resulting in a pronounced 1D silver mobility at room temperature. The covalent regions of the chalcogen substructure account for the lowest activation energies, determined after a detailed analysis of the silver joint probability density functions (jpdf). Impedance spectroscopic measurements were performed in order to substantiate the results from jpdf analyses. Ag10Te4Br3 is an excellent conductor, with conductivities on the same order of magnitude as β-Ag3SX (X = I, Br) or glassy silver chalcogenide halides. The occurrence of the [Te2]2- dumbbell was substantiated by Raman spectroscopy.

Crystal structure of the synthetic analog of grechishchevite and Hg-X (X = S, Se, Te) bond topology in mercury chalcogen halides

This paper analyzes the structural data available for the synthetic analog of the mineral grechishchevite Hg3S2Br1.00Cl0.50I0.50. The crystal structure of the synthetic mineral is refined. For chalcogen halides Hg3X2Hal2 (X = S, Se, Te; Hal = Cl, Br, I), the paper presents an inventory of infinite and isolated ribbons, layers, and frameworks of covalently bonded Hg-X radicals growing into the pseudocubic matrix of halogen atoms.

Selenium sulfur dihalides, ChnX2 (n = 1, 2, 3; Ch = Se, S; X = Br, Cl). Raman and 77Se NMR spectroscopic characterization

Solutions of Se2Cl2 in S2Cl2, Se2Br2 in S2Cl2, Se in S2Cl2, and S in Se2Cl2 have been studied by Raman and 77Se NMR spectroscopy. Selenium sulfur dihalides, SeSCl2, SeSBr2, and SeSBrCl, formed in these solutions, have been shown by Raman and 77Se NMR spectroscopy to have chain structures. Solutions of Se2Cl2 in S2Cl2, S in Se2Cl2, and Se in S2Cl2 have been shown to contain, in addition to Se2Cl2, S2Cl2, SeSCl2, Se3Cl2, and S8, trichalcogen dichlorides Se2SCl2 and SeS2Cl2. Selenium-77 signals corresponding to all seven chain isomers of the expected Se-containing dichalcogen dihalides, Se2Br2, Se2Cl2, Se2BrCl, SeSCl2, SeSBr2, BrSeSCl, and ClSeSBr, have been observed in the spectrum of a 1:1 molar mixture of S2Cl2 and Se2Br2. The disulfur dichloride and dibromide, as well as the bromide chloride, are also present. Selenium–bromine and sulphur–chlorine linkages are observed to be preferred over selenium–chlorine and sulphur–bromine bonding in these mixtures. The 77Se chemical shifts correlate well with the electronegativity of the directly bonded neighbour but inversely with that of the next-nearest neighbour. Keywords: selenium halides, sulfur halides, low valent chalcogen halides, 77Se NMR, Raman spectroscopy.

Alkoxohalogenotellurate(IV): Darstellung und Struktur von Tetraphenylphosphonium-trichloro(dioxo-ethylen-O.O')tellurat(rV) / Alkoxohalogenotellurates(IV): Preparation and Structure of Tetraphenylphosphonium Trichloro(dioxo-ethylene-O,O')tellurate(IV)

Abstract The deprotonated glycolate dianion (OCH2CH2O)2- is shown to react as a bidentate chelating ligand towards chalcogen(IV) halides. With TeCl4, the anion TeCl3(O2C2H4)- is formed. According to a single crystal X-ray analysis of the tetraphenylphosphonium salt (P21/c, a = 7.501, b = 26.328, c = 13.582 A, β= 104.55°, Z = 4) Te is in a tetragonal pyramidal (ψ octahedral) coordination with the alcoholate ligands in the apical (Te-O 1.919 Å) and in one of the equatorial positions (Te O 1.973 Å), the Te-Cl bond lengths being between 2.495 and 2.590 Å. The trans bond lengthening effect of the equatorial alcoholate ligand (i.e. the polarizing effect towards the lone pair) is unusually low. Vibrational spectra are reported.