Zur Reaktion der Meldrumsäure mit Schwefeldichlorid - Synthese und Eigenschaften eines ungewöhnlichen 1,3-Dithietans [1]

On the Reaction of Meldrum's Acid with Sulfur Dichloride - Synthesis and Properties of an Uncommon 1,3-Dithietane [1] The 1,3-dithietane {MelS}₂ ( 8 ) is obtained from Meldrum's acid MelH₂ ( 1 , Mel = C₆H₆O₄) and sulphur dichloride in good yield. 8 reacts with the nucleophiles PPh₃ and 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene ( 12 , Im) to give the zwitterionic compounds Mel-S-PPh₃ ( 11 ) and Mel-S-Im ( 13 ). Aqueous ammonia gives the dianionic disulfide (NH₄)₂[Mel-S-S-Mel] ( 14 ). The crystal structures of 8 , 11 , and 14 are discussed.     

Synthese und Kristallstrukturen der homoleptischen Phosphaniminato‐Kationen [E(NPPh3)3]+ (E = S,Se, Te) mit Iodid und Triiodid als Gegenionen

Synthesis and Crystal Structures of the homoleptic Phosphoraneiminato Cations [E(NPPh₃)₃]⁺ (E = S, Se, Te) with Iodide and Triiodide Counter Ions N‐Iod‐triphenylphosphaneimine, INPPh₃, reacts with the chalcogenes sulfur, selenium and tellurium in boiling tetrahydrofuran to give the phosphoraneiminato complexes [E(NPPh₃)₃]⁺[¹/₂ I₃^–, ¹/₂ I^–] · THF (E = S ( 1 ), E = Se ( 2 )) and [Te(NPPh₃)₃]⁺I₃^– ( 3 ), respectively. The componds form red crystals which are characterized by IR spectroscopy and by crystal structure determinations. The homoleptic cations [E(NPPh₃)₃]⁺ have pyramidal structures with short EN and PN bond lengths, corresponding to double bonds. 1 : Space group Pa 3, Z = 8, lattice dimensions at –80 °C: a = b = c = 2192.9(1) pm, R₁ = 0.0299. 2 : Space group Pa 3, Z = 8, lattice dimensions at –80 °C: a = b = c = 2202.5(1) pm, R₁ = 0.0357. 3 : Space group Pca2₁, Z = 4, lattice dimensions at –90 °C; a = 1075.8(2); b = 1988.8(4); c = 2437.2(3) pm, R₁ = 0.0443.     

On the reactions of the tetraindium cluster In4[C(SiMe3)3]4: Insertion of the monomeric fragments InC(SiMe3)3 into chalcogen-chalcogen bonds

Treatment of the tetraindium cluster In₄[C(SiMe₃)₃]₄ (1) with diaryl dichalcogenides Aryl-E-E-Aryl (E = S, Se and Te) afforded the corresponding RIn(E-Aryl)₂ [R = C(SiMe₃)₃] compounds by insertion of the monomeric fragments InR into the chalcogen-chalcogen bonds. The dimeric formula units adopt different conformations in the solid state (C_i vs. C_2 h).     

Chlorination and Bromination of Dialkyl Tellurides

The reactions of dialkyl tellurides R₂Te (R = C₂H₅, n‐C₃H₇, i‐C₃H₇, c‐C₆H₁₁) with sulfuryl chloride and bromine were examined. The dialkyltellurium(IV) dichlorides (C₂H₅)₂TeCl₂ ( 1 ), (n‐C₃H₇)₂TeCl₂ ( 2 ), (i‐C₃H₇)₂TeCl₂ ( 3 ) and (c‐C₆H₁₁)₂TeCl₂ ( 4 ) were obtained upon reaction with stoichiometric amounts of SO₂Cl₂. Excess of SO₂Cl₂ resulted in formation of mixtures of R₂TeCl₂ and RTeCl₃. Treatment of (C₂H₅)₂Te and (n‐C₃H₇)₂Te with excess bromine gave the dialkyltellurium(IV) dibromides (C₂H₅)₂TeBr₂ ( 5 ) and (n‐C₃H₇)₂TeBr₂ ( 6 ), whereas (i‐C₃H₇)₂Te and (c‐C₆H₁₁)₂Te yielded the alkyltellurium(IV) tribromides i‐C₃H₇TeBr₃ ( 7 ) and c‐C₆H₁₁TeBr₃ ( 8 ). Equimolar amounts of bromine resulted in mixtures of R₂Te and RTeBr₃. All products were identified and characterized by analytical and spectroscopic methods. n‐Propyl tellurium tribromide ( 9 ) was detected from a solution of the dibromide 6 after prolonged periods. The crystal structures of 7 , 8 and 9 were determined.     

Chalkogen‐Derivate der Halbsandwich‐Wolfram(V)‐Komplexe Cp*WCl4 und Cp*WCl4(PMe3). Röntgen‐Kristallstrukturanalysen von anti‐[Cp*W(Se)(μ‐Se)]2 und Cp*W(S)2(OMe)

Chalcogen Derivatives of the Halfsandwich Tungsten(V) Complexes Cp*WCl₄ and Cp*WCl₄(PMe₃). X‐Ray Crystal Structure Analyses of anti ‐[Cp*W(Se)(μ‐Se)]₂ and Cp*W(S)₂(OMe) The chalcogenation of Cp*WCl₄ ( 1 ) by E(SiMe₃)₂ (E = S, Se) and Te(SiMe₂^tBu)₂ in chloroform solution leads to dimeric products of the type anti‐[Cp*W(E)(μ‐E)]₂ (E = S ( 3 a ), Se ( 3 b ) and Te ( 3 c )). An X‐ray structure determination of 3 b indicates a centrosymmetric molecule containing a planar W(μ‐Se)₂W ring, the W–W distance (297.9(1) pm) corresponds to a single bond. In the presence of air the two terminal chalcogenido ligands (E) in 3 a – c are stepwise replaced by oxido ligands (O) to give [Cp*W(O)(μ‐E)]₂ (E = S ( 5 a ), Se ( 5 b ) and Te ( 5 c )) in quantitative yields. The reaction of Cp*WCl₄ with H₂S or ammonium polysulfide, (NH₄)₂S_x (x ∼ 10), leads to Cp*W(S)₂Cl ( 6 a ); the corresponding methoxy derivative, Cp*W(S)₂OCH₃ ( 9 a ), has been characterized by an X‐ray structure analysis. On the other hand, the reaction of Cp*WCl₄(PMe₃) ( 2 ) with sodium tetrasulfide, Na₂S₄, in dimethylformamide solution gives a mixture of mononuclear Cp*W(S)(S₂)Cl ( 8 a ), dinuclear [Cp*W(S)(μ‐S)]₂ ( 3 a ) and a trinuclear side‐product of composition Cp*₂W₃S₇ ( 13 a ). Terminal sulfido ligands are replaced by terminal oxido ligands in solution in the presence of oxygen. Thus, 6 a is stepwise converted into Cp*W(O)(S)Cl ( 10 a ) and CpW(O)₂Cl ( 12 a ), whereas 8 a gives Cp*W(O)(S₂)Cl ( 11 a ) and 13 a leads to Cp*₂W₃(O)S₆ ( 14 a ). The disulfido complexes 8 a and 11 a are desulfurized by triphenylphosphane to give 6 a and 10 a . The new complexes have been characterized by their IR and NMR spectra and by mass spectrometry.     

Polytellurides and Polyselenides – Compounds Containing $_{\infty}^{1}\rm [Te_{6}-Te_{4}]^{4-}$ and [Sn(Se4)3]2− Anions

The reactions of the Zintl phase K₂Cs₂Sn₉ with elemental tellurium and selenium in ethylenediamine have been investigated. From the reaction of K₂Cs₂Sn₉ with elemental tellurium [K‐(2,2,2‐crypt)]₄Te₆Te₄ ( 2 ) and [K‐(2,2,2‐crypt)]₂Sn₂Te₃ ( 3 ) were obtained, whereas the reaction of K₂Cs₂Sn₉ with elemental selenium led to the formation of [K‐(2,2,2‐crypt)]₂Sn(Se₄)₃ ( 4 ) and [K‐(2,2,2‐crypt)]₂Cs₂Sn₂Se₆·2en ( 5 )¹⁾. Compounds 2 , 4 , 5 have been characterized by single crystal X‐ray structure determination.     

Novel Synthesis of Benzotriazol-1-yl Methyl Selenides and Tellurides

Benzotriazole has played an important role as a synthetic auxiliary for preparative chemists1. It is also well known that organic selenides or tellurides are versatile intermediates in organic synthesis2. However, there are only few reports on the synthesis of the difunctionalized compounds containing both benzotriazolyl group and organoselenium or tellurium group3. Herein we wish to report a new and convenient synthesis of benzotriazol-1-yl methyl selenides and tellurides 4a-h.Selenium or tel…     

Trifluoromethylselenate(0), [SeCF3]—, and Trifluoromethyltellurate(0), [TeCF3]— — Crystalline Products of the Reduction of the Bis(trifluoromethyl)dichalkogen Compounds,E2(CF3)2 (E = Se,Te), with Tetrakis(dimethylamino)ethene (TDAE)

[Bis(dimethylamino)ethanediylidene]bis(dimethylammonium) bis(trifluoromethylchalcogenates(0)), (TDAE)[ECF₃]₂ (E = Se, Te), are quantitatively formed from the reductions of E₂(CF₃)₂ with tetrakis(dimethylamino)ethene, TDAE. Both compounds are bright yellow to orange solids which crystallize isostructurally with the corresponding sulfur derivative in the orthorhombic space group Pbca (No. 61). (TDAE)[SeCF₃]₂ has alternatively been prepared by cation exchange from [NMe₄]SeCF₃ and (TDAE)Br₂.     

On the reactions of the tetraindiumcluster In4[C(SiMe3)3]4 with phenylselenium and phenyltellurium bromides

The tetraindiumcluster In₄[C(SiMe₃)₃]₄1 reacted with phenylselenium bromide and phenyltellurium bromide by the insertion of InR groups into the chalcogen-bromine bonds. The oxidation state of the indium atoms increased from +1 to +3. Compounds were obtained in which the indium atoms bear three different substituents (alkyl groups, phenylchalcogenido ligands, and bromine atoms). The products form dimers in the solid state via In-Se-In and In-Te-In bridges, respectively, and the bromine atoms are in terminal positions.     

Stabilization of Unusual Oxidation and Coordination States by the Ligands OSF5, OSeF5, and OTeF5

Compounds with the ligands OSF₅, OSeF₅, and OTeF₅ are now known for most of the chemical elements. The ability of these ligands to stabilize the highest valency levels of the central atoms to which they are bound is unsurpassed by any other polyatomic ligand. Examples are Xe(OTeF₅)₆, Te(OTeF₅)₆, W(OTeF₅)₆, and U(OTeF₅)₆ or I(OTeF₅)₅ and Br(OSeF₅)₃. Because of the ligands' size and internal bonding they hardly ever form bridges, and in this respect they differ from fluorine, although they do share the latter's high electronegativity.     

Synthese und Struktur von 1,3‐Diisopropyl‐4,5‐dimethylimidazolium‐2‐sulfonat: Ein Carbenaddukt des Schwefeltrioxids

Synthesis and Structure of 1,3‐Diisopropyl‐4,5‐dimethylimidazolium‐2‐sulfonate: A Carbene Adduct of Sulfur Trioxide [1] The stable betaine 1,3‐diisopropyl‐4,5‐dimethylimidazolium‐2‐sulfonate ( 5 ) is obtained through hydrolysis of the 2‐chloro‐1,3‐diisopropyl‐4,5‐dimethylimidazolium chloro‐ sulfite salt ( 4 b ) in the presence of cyanide. The crystal structure analysis of 5 is reported.     

An efficient and facile one-pot synthesis of structurally unique 2,4,6-tris(arylchalcogeno)-1,3,5-triazine and 1,3,5-tris(arylchalcogeno)-2,4,6-trimethylbenzene

An efficient one-pot synthesis of a novel class of 2,4,6-tris(arylchalcogeno)-1,3,5-triazine (sulfur, selenium and tellurium) and 1,3,5-tris(arylchalcogeno)-2,4,6-trimethylbenzene (sulfur and selenium)-containing ligands has been developed based on the reaction of 2,4,6-trichloro-1,3,5-triazine and 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene with the corresponding arylchalcogenide anions generated in aqueous tetrahydrofuran.     

锡促进的烯丙基硒醚和烯丙基硫醚的合成

在金属锡促进下，烯丙基溴与二硒醚或二硫醚反应，生成烯丙基硒醚或烯丙基硫醚 。     

Acetylenic Selenides and Tellurides from 1-Bromo, 2-Phenyl Ethyne

Acetylenic selenides and tellurides were prepared in good yields by nucleophilic substitution at acetylenic carbon by reaction of selenolate and tellurolate anions with 1-bromo, 2-phenyl ethyne.     

Synthesis and characterisation of the methylene-inserted mixed-chalcogenide compounds Fe2(CO)6(μ-SeCH2Te) and Fe2(CO)6(μ-SCH2Te)

The methylene-bridged, mixed-chalogen compounds Fe₂(CO)₆(μ-SeCH₂Te) (1) and Fe₂(CO)₆(μ-SCH₂Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe₂(CO)₆(μ-SeTe) and Fe₂(CO)₆(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, ¹H, ¹³C, ⁷⁷Se and ¹²⁵Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P2₁/n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) ų, Z = 4, D_c = 2.599 g cm⁻³ and R = 0.030 (R_w = 0.047).     

Bis-(8-oxo quinoline)diorgano tellurium(IV) compounds; structural and spectroscopic studies

Three new compounds of the type R₂Te(OR′)₂ are reported in which R′ bears a potentially co-ordinating group: bis-(8-hydroxo quinoline)dimethyltellurium (I) bis-(8-oxo-2-methyl quinoline)dimethyltellurium (II), and bis-(8-oxo-quinoline) di-(p-tolyl)tellurium (III). The crystal structures of II and III have been determined. The primary geometry around tellurium in both cases can be described as ψ-trigonal bipyramidal but long Te N contacts in the range 2.840(6)–2.899(4) Å which lie well within the van der Waals distance imply extension of the co-ordination sphere. Variable temperature multi-nuclear (¹ H, ¹³C, ¹²⁵Te) studies of the compounds I, II, and III in solution indicate the presence of a single species over the range 216–343 K. The data do not distinguish between the presence of a single 14-Te-6 pertellurane seen in the crystallographic studies, or that of such a species in equilibrium, rapid on the ¹H and ¹²⁵Te timescales, with the 10-Te-4 tellurane.     

Preparation,Thermal Behaviour and Crystal Structure of the Basic Mercury(II) Tetraoxotellurate(VI), Hg2TeO5, and Redetermination of the Crystal Structure of Mercury(II) Orthotellurate(VI), Hg3TeO6

Single crystals of Hg₂TeO₅ were obtained as dark‐red parallelepipeds by reacting stoichiometric amounts of Hg(NO₃)₂ · H₂O and H₆TeO₆ under hydrothermal conditions (250 °C, 10d). The crystal structure (space group Pna2₁, Z = 4, a = 7.3462(16), b = 5.8635(12), c = 9.969(2)Å, 1261 structure factors, 50 parameters, R[F² > 2σ(F²)] = 0.0295) is characterized by corner‐sharing [TeO₆] octahedra forming isolated chains [TeO_4/1O_2/2] which extend parallel to [100]. The two crystallographically independent Hg atoms are located in‐between the chains and interconnect the chains via common oxygen atoms. Amber coloured single crystals of Hg₃TeO₆ were prepared by heating a mixture of Hg, HgO and TeO₃ together with small amounts of HgCl₂ as mineralizer in an evacuated and sealed silica glass tube (520 °C). The previously reported crystal structure has been re‐investigated by means of single crystal X‐ray data which reveal a symmetry reduction from Ia3¯d to Ia3¯ (Z = 16, a = 13.3808(6) Å, 609 structure factors, 33 parameters, R[F² > 2σ(F²)] = 0.0221). The crystal structure is made up of a body‐centred packing of [TeO₆] octahedra with the Hg atoms situated in the interstices of this arrangement. Upon heating, both title compounds decompose in a one‐step mechanism under formation of TeO₂ and loss of the appropriate amounts of elementary mercury and oxygen.     

Bis(2,6-dimethoxyphenyl) sulfide, selenide and telluride, and their derivatives

2,6-Dimethoxyphenyl derivatives of sulfur, selenium, and tellurium, such as ΦEEΦ, Φ₂E, ΦSeH, [MeΦ₂E]X (X=MeSO₄, ClO₄), Φ₂EO · xH₂O, [Φ₂EOR]ClO₄, [Φ₂EOH]ClO₄ (R=Me, Et), Me₂SnCl₂ · 2Φ₂EO (E=S, Se) [Φ=2,6-(MeO)₂C₆H₃; E=S, Se, Te] have been prepared, and their properties compared with common phenyl derivatives. The reaction rates of Φ₂E with dimethyl sulfate and butyl bromide increased in the order E=S<Se<Te, which were compared with those of Ph₃M and Φ₃M, M=P>As>Sb. These reactivities are parallel with the electrochemical oxidation potentials reported for Ph₂E and with the first ionization potentials reported for Ph₃M. The rate of Φ₂Te was faster than that of Ph₃P and slightly faster than that of Φ₃Sb. From the reactivity of [Φ₂E-Me]⁺ salts with nucleophiles, the E⁺–Me bond strengths were estimated to increase in the order E=Se<S<Te. The reaction rates of Φ₂EO with dimethyl sulfate increased in the order E=S<Se<Te, and the respective rate of Φ₂EO was faster than that of Φ₂E. The origins of these reactivities and bond strengths are discussed.     

Synthesis and Crystal Structure of Cs(VO2)3(TeO3)2, a New Layered Cesium Vanadium(V) Tellurite

Synthetic Cs(VO₂)₃(TeO₃)₂ is built up from infinite sheets of distorted octahedral V^VO₆ groups, sharing vertices. These octahedral layers are “capped” by Te atoms (as parts of pyramidal [Te^IVO₃]^2– groups) on both faces of each V/O sheet, with inter‐layer, 12‐coordinate, Cs⁺ cations providing charge compensation. Cs(VO₂)₃(TeO₃)₂ is isostructural with M(VO₂)₃(SeO₃)₂ (M = NH₄, K). Crystal data: Cs(VO₂)₃(TeO₃)₂, M_r = 732.93, hexagonal, space group P6₃ (No. 173), a = 7.2351(9) Å, c = 11.584(2) Å, V = 525.1(2) ų, Z = 2, R(F) = 0.030, wR(F ²) = 0.063.     

Kupferchalkogenid‐Clusterverbindungen mit Brom‐funktionalisierter Ligandenhülle

Five new copper chalcogenide cluster molecules, [Cu₄(S–C₆H₄–Br)₄(PPh₃)₄] ( 1 ), [Cu₂₂Se₆(S–C₆H₄–Br)₁₀(PPh₃)₈] ( 2 ), [Cu₂₈Se₆(S–C₆H₄–Br)₁₆(PPh₃)₈] ( 3 ), [Cu₄₇Se₁₀(S–C₆H₄–Br)₂₁(OAc)₆(PPh₃)₈] ( 4 ) and [Cu₈(S–C₆H₄–Br)₆(S₂C–NMe₂)₂(PPh₃)₄] ( 5 ) have been synthesized and characterized by single‐crystal X‐ray structure analysis. Compounds 1 – 4 were prepared from the reaction of CuOAc, p‐Br–C₆H₄–SSiMe₃ and Se(SiMe₃)₂ in the presence of PPh₃. In a further reaction of 1 with ⁱPrMgCl and (Me₂N–CS₂)₂ cluster 5 was crystallized.