Die Reaktion von SePh2 mit N‐Chlorsuccinimid. Kristallstrukturen von [SeCl2Ph2] und [SeCl2Ph2(Succinimid)2]

Reaction of SePh₂ with N‐Chlorosuccinimide. Crystal Structures of [SeCl₂Ph₂] and [SeCl₂Ph₂(succinimide)₂] SePh₂ reacts with N‐chlorosuccinimide in acetonitrile solution to give [SeCl₂Ph₂] ( 1 ) and [SeCl₂Ph₂(succinimide)₂] ( 2 ) as colourless crystals, which can be separated by fractional crystallization. According to X‐ray single crystal determinations both compounds contain [SeCl₂Ph₂] molecules with ψ‐trigonal‐bipyramidal coordination at the selenium atom, the chloro ligands being in apical positions. In 2 the dimeric unit (HNC₄O₂H₄)₂ is linked with its [SeCl₂Ph₂] unit via a weak C–H···O hydrogen bond. 1 : Space group Pbcn, Z = 4, lattice dimensions at 193 K: a = 1350.6(1), b = 573.3(1), c = 1503.3(2) pm, R₁ = 0.0326. 2 : Space group I2/a, Z = 4, lattice dimensions at 193 K: a = 1363.9(1), b = 557.7(1), c = 2781.3(1) pm, β = 101.01(1)°, R₁ = 0.0286.     

Die Reaktion von SeCl4 mit Übergangsmetalltetrachloriden. Synthese und Kristallstrukturen von (SeCl3)2MCl6 mit M = Zr,Hf, Mo,Re

The Reaction of SeCl₄ with Transition Metal Tetrachlorides. Synthesis and Crystal Structures of (SeCl₃)₂MCl₆ with M = Zr, Hf, Mo, Re The transition metal tetrachlorides ZrCl₄, HfCl₄ and MoCl₄ react with SeCl₄ in closed ampoules at temperatures of 140°C to (SeCl₃)₂MCl₆ (M = Zr, Hf, Mo) which are all isotypic and crystallize in the (SeCl₃)₂ReCl₆ structure type (orthorhombic, Fdd2, Z = 8, lattice constants for M = Zr: a = 1165.7(1)pm, b = 1287.2(2)pm, c = 2180.2(2)pm; for M = Hf: a = 1162.9(2)pm, b = 1285.0(2)pm, c = 2178.2(3)pm; for M = Mo: a = 1153.8(1)pm, b = 1267.7(1)pm, c = 2147.4(2)pm). The Cl^? ions form a hexagonal closest packing with one fourth of the octahedral holes filled by Se⁴⁺ and M⁴⁺ in an ordered way. The MCl₆ octahedra are regular, the SeCl₆ octahedra are distorted with 3 short and 3 long Se? Cl bonds (mean 215 pm and 287 pm). The structures can thus be regarded as built of SeCl₃⁺ and MCl₆^2? ions. Magnetic susceptibility measurements show for M = Zr the expected diamagnetic behavior, for M = Mo and Re paramagnetic behavior according to the Curie-Weiss law with magnetic moments of 2.5 B. M. for M = Mo and 3.7 B. M. for M = Re corresponding to 2 and 3 unpaired electrons respectivly.     

Die Kristallstrukturen von SeCl3 +SbCl6−, SeBr3+GaBr4−, PCl4+SeCl5− und (PPh4+)2SeCl42− · 2 CH3CN

Crystal Structures of SeCl₃⁺SbCl₆^?, SeBr₃⁺GaBr₄^?, PCl₄⁺SeCl₅^?, and (PPh₄⁺)₂SeCl₄^2? · 2 CH₃CN The crystal structures of the title compounds were determined by X-ray diffraction. SeCl₃⁺SbCl₆^?: Space group P2₁/m, Z = 4, structure determination with 1795 observed unique reflections, R = 0.022. Lattice dimensions at ?80°C: a = 940.9, b = 1066.3, c = 1234.9 pm, β = 102.79°. The compound forms ion pairs with the structure of a double octahedron with linked surfaces. SeBr₃⁺GaBr₄^?: Space group Pc, Z = 2, structure determination with 1461 observed unique reflections, R = 0.058. Lattice dimensions at ?60°C: a = 660.1, b = 655.3, c = 1431.3 pm, β = 101.177°. The compound crystallizes in the SCl₃[AlCl₄] lattice type. Between the ions there are two relatively short Se … Br? Ga contacts. PCl₄⁺SeCl₅^?: Space group Ima2, Z = 8, structure determination with 1757 observed unique reflections, R = 0.029. Lattice dimensions at ?50°C: a = 1651.6, b = 1201.2, c = 1166.4 pm. The SeCl₅^? ions are associated to chains via interionic Se? Cl … Se contacts along the crystallographic c-axis. (PPh₄⁺)₂SeCl₄^2? · 2CH₃CN: Space group P2₁/n, Z = 2, structure determination with 2578 observed unique reflections, R = 0.050. Lattice dimensions at ?80°C: a = 1288.5, b = 726.0, c = 2585.8 pm, β = 101.65°. The compound includes planar-tetragonal SeCl₄^2? ions, which almost meet D_4h symmetry.     

含杂环羧酸基二苄基锡(Ⅳ)配合物的合成与表征

以二苄基二氯化锡和杂环羧酸钠为原料合成了十种新的有机锡配合物(PhCH₂)₂Sn(O₂CR)_nCl_2-n(n=1或2，R=杂环)。用元素分析、IR、 ¹H NMR和TG表征了配合物的组成和结构。     

Chloroselenate mit zwei- und vierwertigem Selen: 77Se-NMR-Spektren,Synthese und Kristallstrukturen von (PPh4)2SeCl6 · 2 CH2Cl2, (NMe3Ph)2SeCl6, (K-18-Krone-6)2SeCl6 · 2 CH3CN,PPh4Se2Cl9, (NEt4)2Se2Cl10, (PPh4)2Se3Cl8 · CH2Cl2 und (PPh4)2Se4Cl12 · CH2Cl2

Chloroselenates with Di- and Tetravalent Selenium: ⁷⁷Se-NMR-Spectra, Syntheses, and Crystal Structures of (PPh₄)₂SeCl₆ · 2 CH₂Cl₂, (NMe₃Ph)₂SeCl₆, (K-18-crown-6)₂SeCl₆ · 2 CH₃CN, PPh₄Se₂Cl₉, (NEt₄)₂Se₂Cl₁₀, (PPh₄)₂Se₃Cl₈ · CH₂Cl₂, and (PPh₄)₂Se₄Cl₁₂ · CH₂Cl₂ The title compounds were obtained from reactions of selenium and selenium tetrachloride with PPh₄Cl, NEt₄Cl, NMe₃PhCl, or (K-18-crown-6)Cl in dichloromethane or acetonitrile. (PPh₄)₂Se₃Cl₈ · CH₂Cl₂ was also formed from GeSe, PPh₄Cl and chlorine in acetonitrile. The ⁷⁷Se-NMR spectra of the solutions show the presence of dynamical equilibria which, depending on composition, mainly contain SeCl₂, SeCl₄, Se₂Cl₂, SeCl₆^2–, Se₂Cl₆^2–, and/or Se₂Cl₁₀^2–. Solutions of AsCl₃ and (PPh₄)₂Se₄ in acetonitrile upon chlorination with Cl₂ or PPh₄AsCl₆ yielded (PPh₄)₂Se₂Cl₆, while (PPh₄)₂As₂Se₄Cl₁₂ was the product after chlorination with SOCl₂. According to the X-ray crystal structure analyses the ions SeCl₆^2–, Se₂Cl₉^–, and Se₂Cl₁₀^2– have the known structures with octahedral coordination of the Se atoms. The structure of the Se₃Cl₈^2– ion corresponds to that of Se₃Br₈^2– consisting of three SeCl₂ molecules associated via two Cl^– ions. (PPh₄)₂Se₄Cl₁₂ · CH₂Cl₂ is isotypic with the corresponding bromoselenate and contains anions in which three SeCl₂ molecules are attached to a SeCl₆^2– ion; there is a peculiar Se–Se interaction.     

Ab initio Study of Anharmonic Force Field and Spectroscopic Constants for Germanium Dichloride

Ab initio study of the equilibrium structure, spectroscopy constants, and anharmonic force field for several isotopomers of germanium dichloride (⁷⁰GeCl₂, ⁷²GeCl₂, and ⁷⁶GeCl₂) have been carried out at the MP2 and CCSD(T) levels of theory using cc-pVTZ basis set. The calculated geometries, rotational constants, vibration-rotation interaction constants, harmonic frequencies, anharmonic constants, quartic and sextic centrifugal distortion constants, cubic and quartic force constants are compared with experimental data. For small mass differences of the Ge isotopes, the isotopic effects for germanium dichloride are much weaker. The agreements are satisfactory for these two methods, but the deviations of CCSD(T) results are slightly larger than that of MP2, because of CCSD(T)'s inadequate treatment of electron correlation in hypervalent Cl atom.     

A new one pot high yield synthesis of ditertiarybutylselenide

^tBu₂Se can be prepared in >75% yield from the reaction of SeCl₂, formed in situ from SeCl₄ and Se in tetrahydrofuran, with ^tBuLi.     

The use of selenium(IV) chloride for the preparation of diarylselenium dichlorides

Two new synthetic routes for the preparation of diarylselenium dichlorides are reported both of which use selenium(IV) chloride as a starting meterial. In the first method, bis(p-methóxyphenyl) and bis(p-ethoxyphenyl)-selenium dichlorides are prepared by the reaction of SeCl₄ with anisole and phenetole respectively. In the second, diphenylselenium dichloride is prepared by the reaction of SeCl₄ with tetraphenyllead, a reaction in which the lead—carbon bond is cleaved.The far infrared and Raman spectra of the diarylselenium dichlorides are reported.     

大取代茂锆配合物合成及分子内消除反应研究

通过6,6-二烷基富烯与2-MeOArLi进行加成反应, 得到含芳氧取代的环戊二烯基锂盐, 再与取代茂三氯化锆反应, 合成了不对称大位阻取代茂锆配合物RCpCp^oZrCl₂ [Cp^o＝2-MeOArCR¹R²Cp, R¹, R²＝CH₃, C₂H₅, (CH₂)₅, etc.], 所得的配合物均通过¹H NMR, IR, MS和EA鉴定. 在此过程中发现该类配合物能进行分子内消除反应, 脱去苯甲醚得到烯基取代的二氯二茂锆配合物, 该反应为未见文献报道的新反应, 对该反应进行了研究.     

Structure and Phase Transitions in Ethylenediammonium Dichloride and its Salts with Antimony Trichloride

During the mixing of ethylenediammonium dichloride and antimony trichloride except of reported earlier [NH₃(CH₂)₂NH₃]₅(Sb₂Cl₁₁)₂ · 4 H₂O a new salt [NH₃(CH₂)₂NH₃](SbCl₄)₂ was obtained. The crystals are monoclinic at 295 K, space group C2/m, a = 13.829(3), b = 7.408(1), c = 7.588(2) Å; β = 103.18(3)°; V = 756.9(3) ų; Z = 2; d_c = 2.585, d_m = 2.56(2) g · cm^–3. The structure consists of anionic sublattice built of Sb₂Cl₈^2– units composed of two SbCl₅^2– square pyramids connected by edge. The ethylenediammonium cations are located in anionic cavities. The cations are disordered. Each methylene carbon atom is split between two positions. The X‐ray diffraction, DSC, TGA and dilatometric methods were used to investigate properties of ethylenediammonium dichloride and its two salts with antimony trichloride. In [NH₃(CH₂)₂NH₃]Cl₂ one phase transition of first order and of the order‐disorder type was found at 402 K. The [NH₃(CH₂)₂NH₃]₅(Sb₂Cl₁₁)₂ · 4 H₂O undergoes one transition at 355 K which is accompanied by the dehydration of the sample. In [NH₃(CH₂)₂NH₃](SbCl₄)₂ two phase transitions of the order‐disorder type: of first order at 238 K and of second order at 267 K were found. All those transitions in ethylenediammonium salts share common features. They were related to the changes in the molecular dynamics of ethylenediammonium cations. In the low temperature phases cations are ordered, while above T_c they are characterised by overall reorientations along the axis passing through opposite nitrogen atoms.     

Diorganotin(IV) Complexes of Some Schiff Bases With a Potential Biological Activity

Diorganotin dichloride compounds, Rl₂SnCl₂ (R=Me, nBu, Ph) react with Schiff bases (L), derived from substituted and non-substituted 2- or 3-aminopyridine with 2-hydroxy-, 2-methoxy- or 2-hydroxy-3-methoxy-benzaldehyde in a 1 : 1 molar ratio, to give complexes of general formula R₂SnCl₂·L. It is suggested that the Schiff bases coordinate with tin in bidentate fashion to give hexacoordinate tin species. Almost all the complexes prepared show some 1 : 1 molar conductivity in ethanol and DMF, indicating on R₂Sn(L)Cl⁺ Cl⁻ ionic structure type. The complexes were screened against seven species of bacteria.     

Electrophilic addition of selenium and telluriom halides to methyldiethynylsilane

Regio- and stereoselective electrophilic addition reactions of SeCl₂, SeBr₂, SeCl₄, SeBr₄ to methyldiethynylsilane lead to predominant formation of the Z-isomers of 3,6-dihalo-4-methyl-1,4-selenasilafulvenes, disiloxanes on their bases, as well as disiloxanes formed upon the reaction with methyldiethynylsilane. TeCl₄ reacts with methyldiethynylsilane with predominant formation of the E-isomer of 1,1,3,6-tetrachloro-1-methyl-1-(methyldiethynylsiloxy)-1,4-tellura(IV)silafulvene as a result of the reaction of the intermediate E-isomer of 4-methyl-1,1,3,6-tetrachloro-1,4-tellura(IV)silafulvene with methyldiethynylsilane. The structure of the products was proved by the methods of ¹H, ⁷⁷Se NMR, IR spectroscopy and chromatomass spectrometry.     

An efficient approach for the synthesis of functionalized selenoethers and selenacalix[4]thiophenes, {2,5-(μ-Se)(3,4-dialkoxythiophene)}4

An efficient method for the synthesis of selenoethers and selenacalix[4]thiophene utilizing SeCl₂ is described. Reactions of phenols with SeCl₂ produce the corresponding selenoethers in moderate to good yields. The selenacalix[4]thiophenes, [–Se-3,4-(C₄(OR)₂S)]₄ (R = CH₃, C₆H₁₃) were synthesized by convenient one-pot electrophilic aromatic substitution reaction of dialkoxy thiophene with SeCl₂ in good yield.     

Synthesis, structure and biological activity of amide-functionalized titanocenyls: Improving their cytotoxic properties

Nine amide-functionalized titanocenyls have been synthesized and characterized by spectroscopic and analytical methods and the solid state structure of Cp(CpCO-NH-C₆H₄-OCF₃)TiCl₂ was determined by single crystal X-ray diffraction. X-ray analysis of Cp(CpCO-NH-C₆H₄-OCF₃)TiCl₂ showed that titanium is in a pseudo tetrahedral geometry and contains a Ti-O(amide) coordination. In principle, Ti-O coordination should provide more hydrolytic stability to the corresponding titanocenyls than titanocene dichloride. The cytotoxic activities of these amide-functionalized titanocenyls on HT-29 colon cancer cell line were determined by MTT assay to elucidate structure-activity relationship. All complexes were more cytotoxic than titanocene dichloride and there is no correlation between the para substituents on the phenyl ring and their cytotoxicities.     

Synthesis of diaryl selenides using the in situ reagent SeCl2

Reactions of in situ prepared SeCl₂ with Grignard reagents (prepared from bromobenzene, o-tolyl bromide, 2,6-dimethyl-4-tert-butyl-1-bromobenzene, and 1-bromo-2-methylnaphthalene) and dilithiated benzamides (prepared from N-phenyl, N-cyclohexyl, and N-isopropyl benzamide) are described.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN, [Ph₄P]₂[Se₂Cl₆], and [Ph₄P]₂[Se(Se₅)₂] By symproportionation of elemental selenium and SeCl₄ in polar protic solvents the novel chloroselenates(+II), [SeCl₄]^2? and [Se₂Cl₆]^2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl₄]^2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph₄P]₂[Se₂Cl₆] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se₂Cl₆]^2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se₅)₂]^2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph₄P]₂[Se(Se₅)₂] (space group P2₁/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se₅)₂]^2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se₅]_2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.     

Gleichgewichtsdruckmessungen im System Se/O/Cl

Equilibrium Measurements in the System Se/O/Cl The evaporation and decomposition behaviour was Studied by total pressure measurements in equilibrium with condensed phases as well as in the unsaturated Vapour. The composition Cl/Se = 4 shows the lowest, the composition Cl/Se = 2 the highest total pressure in the Barogramm of the system Se/Cl. Solid SeCl₄ and liquid Se₂Cl₂ exist as condensed compounds whereas only SeCl₂ exists in the gas. The following data were derived (see ?Inhaltsübersicht”?) from the decomposition sublimation SeCl₄, the decomposition of Se₂Cl₂ and the evaporation and decomposition of SeOCl₂.     

Behaviour of Bu(CH2—CHCH2)SnCl2 in water and water-cosolvent media: An approach to understanding the chemical degradation of organotins in aquatic environments

The behaviour of allylbutyltin dichloride in water, water–ethanol and water–hexane media, under either homogeneous or heterogeneous conditions, has been studied. 1,3-Diallyl-1,3-dibutyl-1,3-dichlorodistannoxane, butyltin di(hydroxy)chloride and butyltin trichloride arise from the solvolytic, acid–base and degradation processes. The degradation process involving the cleavage of the tin–carbon allyl bond has been interpreted to occur via an intramolecular reaction at the expense of the cation [Bu(CH₂=CHCH₂)Sn(OH)(H₂O)_n]⁺. The mechanistic pathway is ascribable to an internal interaction of the electrophilic cation with a bonded water molecule. This mechanistic proposal may be of some help with understanding of the chemical degradation of diorganotin derivatives in aquatic environments.     

Bromo- and chloro-selenate(II) compounds

Addition of R₄NX (R = Et, n-Pr, n-Bu) to solutions of SeX₂ (X = Cl, Br) in acetonitrile results in the formation of tri- and tetra-haloselenate(II) complexes (SeX₃⁻ and SeX₄²⁻). Raman spectroscopic characterization of these solutions and solids, R₄NSeX₃ and (R₄N)₂SeX₄, which may be crystallized from them, are reported. R₄NSeCl₃ compounds are shown to be relatively unstable; they are readily destroyed by laser light, 2R₄NSeCl₃ = (R₄N)₂SeCl₆+Se(O) and especially sensitive to hydrolysis, 2SeCl₃⁻+H₂O = SeOCl₃⁻+2HCl+Cl⁻+ Se(O). The Raman spectra of solutions of SeX₃⁻ and SeX₄²⁻ are consistent with T-shaped and square planar structures, respectively.     

Darstellung und Kristallstruktur von β-[SeCl3][MoOCl4]

Preparation and Crystal Structure of β-[SeCl₃][MoOCl₄] The reaction of Se₄[MoOCl₄] and Te₄[MoOCl₄] with SOCl₂ as solvent at 150 °C and 80 °C yields [SeCl₃][MoOCl₄] and [TeCl₃][MoOCl₄] respectively within 3 to 6 days as yellow-brown, moisture-sensitive crystals. [TeCl₃][MoOCl₄] was obtained in the already known monoclinic form, while β-[SeCl₃][MoOCl₄] crystallizes in a new polymorphic triclinic form (P1¯, Z = 2, a = 752.7(2), b = 812.8(2), c = 956.9(3) pm, α = 92.55(3)°, β = 111.63(2)°, γ = 107.39(3)°). The structure contains centrosymmetric tetranuclear units ([SeCl₃]₂[Mo₂O₂Cl₈]) which are analogous to the entities found in the structure of [SCl₃][MoOCl₄]. The packing of the molecules in β-[SeCl₃][MoOCl₄] and [SCl₃][MoOCl₄] is distinctely different.