Über polystannane: IV. Vergleich von abständen d(SnSn), NMR-Kopplungen 1J(Sn) und Valenzschwingungen ν(SnSn) in acetat-verbrücketen distannanen Ph4Sin2(X3CCO2) (X = H,Cl, F)

The three compounds Ph₄Sn₂(X₃CCO₂)₂ were synthesized from Ph₂SnH₂ and X₃CCOOH (X = H, Cl) or by cleavage of two phenyl groups in Ph₆Sn₂ with Stoichiometric amounts of X₃CCOOH (X = Cl, F). The crystal structures (R = 0.041, 0.030, 0.058) show that the Ph₄Sn₂ units are bridged by two isobidentate acetates resulting in five-coordinated tin atoms. Five crystallographically independent centrosymmetric molecules form three distinct conformers. Bonding parameters (compared with Ph₆Sn₂): distances d(SnSn) 269, 271, 272, 277 pm; NMR couplings (CDCl₃ solution) ¹J(SnSn) 16870, 9443, 12915, 4480 Hz; stretching vibrations ν(SnSn) 152, 155, 157, 159 cm⁻. The ion pairs [Ph₄Sn₂]²⁺ [(X₃CCO₂)₂]²⁻ are discussed.     

Verres du systeme La2S3La2O3Ga2O3Ga2S3

The extent of the glass forming region is described as a function of the composition and of the cooling speed. The shape of this region is explained from the previously described La₂S₃La₂O₃Ga₂O₃Ga₂S₃ phase diagram. Glasses are obtained after relatively slow cooling (5°/min), in a definite region of compositions, which coincides with a relatively large concentration of ternary invariants. The thermal properties (transition temperatures and crystallization temperatures) were measured by DTA. For a relatively large region of compositions, glasses return to the equilibrium conditions with intermediate formation of the La_3.33Ga₆S₁₂O₂ metastable crystalline phase. An approach to the structure of the glasses is made by comparison with the crystal structures of the numerous ternary and quaternary crystalline compounds observed in the system, and by the comparison of the Raman spectra. It appears that these gallium oxysulfide glasses have many structural analogies with germanium sulfide glasses.     

Reassignment of the infrared spectra of SnPh3Cl. An infrared method to characterize SnPh3Cl 1—1 adducts

The stretching vibrations of the SnC₃Cl group in the infrared spectrum of SnPh₃Cl have been reassigned on the basis of an SnC₃ group belonging to the C_3ν point group which is replaced by D_3h in SnPh₃Cl₂TMN (TMN = tetramethylammonium). The important shift (108 cm⁻¹) of ν_sSnC₃ from SnPh₃Cl to SnPh₃Cl₂ TMN is due to a “C_3ν point group inversion” (ν_sSnC₃ is higher in frequency than ν_asSnC₃ in the i.r. spectrum of SnPh₃Cl).     

The excess enthalpies of liquid GaGeTe and GaSnTe alloys

The excess enthalpies of the liquid alloys GaGeTe and GaSnTe were measured in a heat-flow calorimeter at 1203 K. The enthalpy surface in the ternary space in both systems is characterized by a valley stretching from the exothermic minimum in the GaTe system to the minima of the GeTe and SnTe systems. The minima in the ternary systems were found in this valley, i.e. on the sections Ga₂Te₃-GeTe and Ga₂Te₃-SnTe. A comparison of the experimental data with those calculated from the excess enthalpies of the constituent binaries with the aid of the Bonnier model, reveals only small deviations. A preliminary investigation was made into the ternary phase diagram of GaSnTe. This system contains the two quasibinary sections Ga₂Te₃-SnTe, GaTe-SnTe and the ternary compound Ga₆SnTe₁₀. The previously reported compounds Ga₂SnTe₃ and GaSnTe₂ do not exist.     

Synthesis of Ph2LSn(μ-OH)Bu3SnCl. Trapping of monomeric triorganotin hydroxide Ph2LSnOH

The reaction of triorganotin(IV) compound Ph₂LSnCl (1), (L = 2,6-(t-BuOCH₂)₂C₆H₃), with (Bu₃Sn)₂O resulted to the isolation of Ph₂LSn(μ-OH)Bu₃SnCl (2), in which a monomeric triorganotin(IV) hydroxide Ph₂LSnOH intermolecularly coordinates Bu₃SnCl moiety. Compound 2 was characterized by combination of ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy, ESI/MS, elemental analysis and X-ray diffraction.     

Tantalum dicyclopentadienyl hydrides containing the TaSn σ-bond. Crystal and molecular structure of (η5-C5H5)2TaH2Sn(CH3)Cl2

Interaction of Cp₂TaH₃ (Cp = η⁵-C₅H₅) with Me_nSnCl_4-n (n = 0–2) in benzene leads to heterometallic complexes with the composition Cp₂TaH₂(SnMe_nCl_3-n). The complex Cp₂TaH₂(SnMe₂Cl) can be obtained only when the HCl eliminated is fixed with triethylamine. The Mössbauer, IR and ¹H NMR spectroscopy data show that these compounds have a symmetrical structure with two terminal TaH bonds and a central TaSn σ-bond. The Cp₂TaH₂(SnMeCl₂) complex was studied by X-ray analysis. The crystals of this compound are rhombic with the unit cell parameters a 7.7361(1), b 10.552(1), c 16.943(3) Å, space group P_cmn, R = 0.0264, R_w = 0.0278. The molecule Cp₂TaH₂(SnMeCl₂) possesses a mirror symmetry plane which passes through the centers of the Cp cycles and the Ta, Sn, and C atoms of the methyl group: d(TaSn) 2.752(1), d(Ta-H) 1.61(10) Å. On the basis of spectroscopic and structural data the TaSn bond is concluded to have increased s character.     

Über das Mischungsverhalten von Nb3Sn mit Ti3Sn,Mo3Al und verwandten Phasen

Zusammenfassung Nb₃Sn und Mo₃Al bilden eine lückenlose Mischreihe. Nb₃Sn löst bei 1600°C rd. 60 Mol% Ti₃Sn, 30 Mol% Zr(3)Sn, 40 Mol% Hf(3)Sn bzw. 50 Mol% Nb(3)Si.Mit 5 Abbildungen     

202 MHz 31P NMR performances: Part II. The challenge of the {[HN(CH2)2NH] N3P3Cl3}2[HN(CH2)nNH] cyclophosphazenic species

202.458 MHz ³¹P NMR (Bruker WM 500) performances are illustrated for new cyclophosphazenes whose ABC systems, that is 3 expected doublets of doublets, give singles or “deckle-edged” singlets when using low-field NMR equipment.     

The thermal transformation of Na LiA zeolites. A new polymorph in the system Li2OAl2O3SiO2

High-temperature phase transformations of A zeolite with various degrees of exchange of Na⁺ with Li⁺ ions were investigated. An increase in the number of Li⁺ ions per unit cell accelerates the thermal transformation of the zeolite framework to the amorphous state. Above 730°C, four phases (carnegieite, nepheline, β-eucryptite, and a new phase—γ-eucryptite) were identified. Only γ- and β-eucryptite phases were obtained from pure LiA zeolite. γ-eucryptite is a new metastable polymorph in the system Li₂OAl₂O₃SiO₂. γ-eucryptite a₀ = 7.231(3)Å, b₀ = 10.270(6) Å, c₀ = 12.054(7) Å) is transformed to β-eucryptite (a₀ = 10.533(5) Å, c₀ = 11.148(5) Å) above 840°C.     

(Me3Sn)2SbSb(SnMe3)2, 1∞-verknüpfte SbSb-Hanteln in einem thermochromen Distiban mit Schweratomgerüst

Single crystals of the thermochromic distibane (Me₃Sn)₄Sb₂ (1) are obtained by irradiation of (Me₃Sn)₃Sb with sunlight. The crystal structure of 1 is reported as linear chains of distibane molecules in trans conformation with Sb ⋯ Sb contacts of 389 ppm. Diffuse reflexion spectra of 1 in the solid state and in solution demonstrate thermochromic effect. The Raman spectrum of solid 1 exhibits strong absorption at 162 cm⁻¹ for ν(Sb₂).     

Total synthesis of erythronolide B. 2. Skeleton assembly in (C5C9) + (C3C4) + (C1C2) + (C11C13) sequence.

Erythronolide B has been synthesized starting from levoglucosan.     

Synthesis and Crystal Structure of (CH_2)_3(3,5-Me_2Pz)_2. [PhBr_2Sn(CH_2)SnBr_2Ph].2HBr.H_2O (Pz=pyrazole)

1 INTRODUCTION The coordination chemistry of tin or organotin toward poly(pyrazol-1-yl)borate ligands has been extensively investigated in recent years owing to the antitumor activity of some related organotin derivatives containing N-donor ligands. A number of organotin(Ⅳ) complexes containing poly(pyrazol- 1-yl)borate ligands have been synthesized and characterized[1~3], some of which have also shown interesting structural characteristics and reactivities[4~6]. Recently, poly(pyrazol…     

The system YPO4Ca3(PO4)2Ca2P2O7

The ternary system YPO₄Ca₃(PO₄)₂Ca₂P₂O₇ has been investigated by differential thermal analysis, powder X-ray diffraction, and microscopy in reflected light. Its phase diagram and isothermal section at room temperature have been determined. The system contains only one double phosphate which is formed at the 1:1 molar ratio YPO₄:Ca₃(PO₄)₂, i.e., Ca₃Y(PO₄)₃.     

可充镁电池有机电解液Mg(SnPh3)2的研究

合成了可用于可充镁电池的一种新型电解液Mg（SnPh3）2,其分解电压为1.2V（相对Mg参比）。循环伏安、交流阻抗和电化学性能测试结果表明用它作为可充镁电池的电解液,电池有较好的循环性能。     

Phase diagram for the system Bi2O3CaOSrOCuO in the SrO-rich region

It has been found experimentally that phase diagram for the system Bi₂O₃CaOSrOCuO in SrO-rich region at 850°C in the open air includes three elementary tetrahedra: CaOSrOSr₆Bi₂O₁₁Sr₂CuO₃, CaOSr₂CuO₃Sr₆Bi₂O₁₁Sr_3,5Ca_0,5Bi₂O₇ and Sr₃Bi₂O₆Sr₆Bi₂O₁₁Sr_3,5Ca_0,5Bi₂O₇ Sr₂CuO₃. In the considered interval of corresponding oxide concentrations quaternary oxides are not formed under the above conditions.     

Etudes sur le système ternaire SnInS. Analyses thermique differentielle et radiocristallographique du pseudobinaire SnSIn2S3. Croissance en phase vapeur et caractérisation de composés a valences mixtes de l'étain

The SnInS ternary system has been studied using two different methods of crystal synthesis. By direct combination of the two sulfides (SnS and In₂S₃) various melts have been prepared, and the ternary phase diagram determined by differential thermal analysis. Three ternary phase are found: In₂Sn₂S₅, In₂SnS₄, and In₁₂Sn₅S₂₃. Chemical vapor transport (CVT), using iodine as transport gas, leads to different crystal morphologies (needles, sheets, and polyhedra) according the ratio of iodine to reagent. Several methods have been used to characterize the crystals, specifically X-ray diffraction, electronic microscopy, and Mössbauer spectrometry. The latter shows that both Sn(II) and Sn(IV) are present in all the crystals prepared by CVT.     

离子型化合物{[Ph2Sn]2[2,6-Py(CO2)2]3H2O}2-[HNEt3]+2 的合成及晶体结构研究

在三乙胺作碱的条件下 ,用三苯基氯化锡和 2 ,6 -吡啶二甲酸以 1∶ 1摩尔比反应 ,合成了离子型有机锡化合物 { [Ph2 Sn]2 [2 ,6 -Py( CO2 ) 2 ]3 H2 O} 2 - [HNEt3 ]+2 。用 X-射线单晶衍射测定了该化合物的晶体结构。化合物为单斜晶系 ,空间群 P2 1 /n,a=1 .70 73( 7) nm,b=1 .74 47( 7) nm,c=2 .4 333( 1 0 ) nm,β=1 0 9.6 94 ( 7)°,Z=4 ,V=6 .82 4 ( 5 ) nm3 ,Dx=1 .2 82 g/cm3 ,μ=0 .793mm- 1 ,F( 0 0 0 ) =2 6 96 ,R1 =0 .0 5 6 3,WR2 =0 .1 5 39。化合物中两个锡原子呈七配位畸变五角双锥构型