Synthesis and Molecular and Crystal Structure of K4.5{[Mo3(μ3-Te)(μ2-Te2)3(CN)6]I}I1.5·3H2O and Cs3{[Mo3(μ3-Te)(μ2-Te2)3(CN)6]I}·2H2O

Crystal structures of two new compounds containing trigonal tellurium-bridged cluster fragments [Mo₃(₃-Te)(₂-Te₂)₃]⁴⁺ were investigated. Crystal data for K_4.5{[Mo₃(₃-Te)(₂-Te₂)₃(CN)₆]I}I_1.5·3H₂O: space group , Z = 4, a = 13.280(1), c = 23.800(3) , V = 3635.0(6) ³, d _calc = 3.432 g/cm³, R ₁ = 0.0335, wR2 = 0.0912 for 1378 I _hkl > 2 _I from 3545 measured I _hkl ; for Cs₃{[Mo₃(₃-Te)(₂-Te₂)₃(CN)₆]I}·2H₂O: space group P2 ₁ /n, Z = 2, a= 9.650(2) , b = 22.297(5), c = 27.446(7) , = 94.10(2)°, V = 5890(2) ³, d _calc = 4.273 g/cm ³, R ₁ = 0.0384, wR ₂ = 0.0744 for 957 I _hkl > 2 _I from 3758 measured I _hkl (Enraf-Nonius CAD-4 diffractometer, MoK , graphite monochromator). In both compounds, ionic pairs {[Mo₃Te₇(CN)₆]I}^3– with Te_ax...I^– distances of 3.358-3.676 are formed. In the potassium salt, the {[Mo₃Te₇(CN)₆]I}^3– anion pairs are linked by the additional Te_eqI^– short contacts of 3.460 into two-dimensional corrugated layers perpendicular to the c axis of the unit cell. The structure of the cesium salt is ionic with interstitial H₂O molecules and double-layer closest packing of anions.     

Synthesis and characterization of the new mixed-metal,mixed-chalcogen clusters Fe2 M(CO)10(μ3-S)(μ3-Te) (M=W,Mo). crystal structure of Fe2W(CO)10(μ3-S)(μ3-Te)

The new clusters Fe₂ M(CO)₁₀(µ₃-S)(µ₃-Te), I (M=W) and 2 (M=Mo) have been isolated from the room temperature reaction of Fe₂(CO)₆(µ-STe) andM(CO)₅(THF) (M=W, Mo), respectively. Compounds1 and2 have been characterized by IR, 125 Te NMR spectroscopy, and elemental analysis. The structure of compound1 has been established by X-ray crystallography. It belongs to the triclinic space groupP witha=6.844(2) Å,b=9.397(2) Å,c=13.681(10) Å, =81.64(2)°,=81360r,=812(2)°,V=861.2(3) ų,Z=2,D _e =2.835 g cm^–3. Full-matrix least-squares refinement of1 converged to R=0.043, andR _w .=0.115. The structure consists of a Fe₂ WSTe square pyramid and the W atom occupies the apical site of the square pyramid.     

MOLYBDENUM-IRON MIXED METAL CLUSTERS (Ⅰ)——THE SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF (η~5-C_5H_5)_2Mo_2Fe_2(μ_4-Te)(μ_3-Te)_2(CO)_6

The reaction of Fe_2(μ_3-Te)_2(CO)_9 with Mo_2(CO)_6(η~5-C_5H_5) affords the title compound. Its X-ray analysis shows a butterfly structure for the Mo_2Fe_2 core; the two molybdenum atoms occupy the hinge with a Mo—Mo bond distance of 2.819 and the two iron atoms are on the tops of the wings with an average Mo—Fe bond distance of 2.932(2). Each molybdenum is bonded to a Cp ring, and three CO ligands are terminally bonded to each iron atom. One tellurium atom quadruply bridges Mo_Fe_2 with Mo—Te(μ_4)=2.625(2). and Fe—Te(μ_4)=2.713(2). Two tellurium atoms triply bridge the two triangular Mo_2Fe faces with Mo—Te(μ_3)=2.678(1) and Fe—Te(μ_3)=2.513(3). The molecule has C_(2v) symmetry and a bicapped triangle bipyramidal skeleton. Crystallographic parameters are as follows: space groupImm2(orthorhombic), a=14.562(3), b=10.391(1), c=7.139(4), V=1080.2(i)~3, Z=2, ρ(cald)=1.819g·cm~(-3). The final R factor was 2.2％ for 620 independent reflections(I>2σ(I)).     

钼铁混合金属原子簇的研究——Ⅰ.(η~5-C_5H_5)_2Mo_2Fe_2(μ_4-Te)(μ_3-Te)_2(CO)_6的合成和结构表征

本文用Fe_3(μ_3-Te)_2(CO)_9同Mo_2(CO)_6(η~5-C_5H_5)_2反应合成出标题化合物。结晶学参数如下:空间群Imm2,620个I≥2σ(I)的独立衍射参加最小二乘法修正结构,最终R因子值为0.022。X射线分析表明Mo_2Fe_2形成一蝴蝶型结构,其中两钼原子占据两蝴蝶翼的交界处,Mo—Mo=2.819。两个铁则处于蝴蝶翼的顶端,Mo—Fe=2.932(2)。每个钼原子与一个环成二烯基键联,三个羰基配体以端基的形式与每个铁原子键联。一碲原子处在蝴蝶型开口的上方键联四个金属原子,Mo—Te(μ_4)=2.625(2),Fe—Te(μ_4)=2.713(2)。两个μ_3-碲原子处在μ_4-Te原子的对面,分别处在二个FeMo_2三角面上,Mo—Te(μ_3)=2.678(1),Fe—Te(μ_3)=2.513(3)。整个分子具有严格的C_2v对称性,整个簇骼结构可看成双帽三角双锥构型。     

(1,3,5-C3P3H3)M与(1,3,5-C3P3H3)2M (M=Ti,V, Cr)配合物的结构与芳香性

运用密度泛函理论研究了(1,3,5-C3P3H3)M和(1,3,5-C3P3H3)2M (M=Ti,V,Cr)的结构、键合能以及芳香性.结果表明:低自旋的(1,3,5-C3P3H3)M和(1,3,5-C3P3H3)2M基态结构分别具有C3v和D3h对称性.金属与配体间为共价作用,二者之间存在σ、π和σ三种成键方式.V的三明治配合物的解离方式与Ti和Cr的三明治配合物不同,前者为分步解离,后两者则为一步解离.其中(1,3,5-C3P3H3)2Cr(D3h)的第一解离能最大,配合物最稳定.这些三明治和半三明治配合物都具有中心芳香性、内芳香性和外芳香性,且中心芳香性均大于自由配体(1,3,5-C3P3H3)的中心芳香性,芳香性主要贡献来源于π键和金属原子的孤对电子.内芳香性按照Ti、V、Cr的顺序依次增大,且内芳香性明显要大于外芳香性.高自旋的半三明治(1,3,5-C3P3H3)Ti(C3,5A1)与单重态(1,3,5-C3P3H3)Ti (C3v,1A1)相比,配体的变形性增大,稳定性增加,且C平面中心芳香性和内芳香性均增大,但P平面的中心芳香性却降低.     

Eu2+在M3La3(BO3)4(M=Ca,Sr,Ba)中的发光性质

本文研究了Eu²⁺离子在M_yAl_xBO_y+3/2(1+x)(M=Ca,Sr,Ba)基质中的发光性质及磷和卤素对发光的影响。 采用以H₂和N₂混合气体为还原气氛在高温下进行固相反应的方法合成了一系列磷光体。发现,在CaAl_xBO_2.5+3/2x基质中,当X在0.5～2的范围内时及在Sr_yAl₂BO_{4 6+}基质中,当y在2～6的范围时掺入的Eu³⁺不能被H₂还原为Eu²⁺。其他Eu²⁺激活的磷光体一般都产生f～d跃迁的宽带发射,发射峰的波长随着基质组成的不同可在400～600nm的区间的变化。     

配合物[M(CO)3(PPh2py)2](M=Fe,Ru)异构体的理论研究

对PPh2py配合物[M(CO)3(PPh2py)2](M=Fe, Ru)的三种构型的异构体1-6进行了研究. 其中PPh2py以两个P原子与M配位形成HH构型1(Fe)和4(Ru), 以一个P和一个N原子与M配位形成HT构型2(Fe)和5(Ru), 以两个N原子与M配位形成HH’构型3(Fe)和6(Ru). 结果表明, (1) PPh2py中P原子对HOMO轨道的贡献最大, PPh2py作为电子给体时易以P原子与金属原子结合. (2)从分子能量和相互作用能数据表明, 配合物中HH构型最稳定, HH'构型最不稳定, 这与合成产物为HH构型的结果一致. (3) 键长和Wiberg键级均表明P—M键比N—M键结合力强. P、M原子间存在σ键, 而N、Fe原子间仅存在nN→n*M或nN→σ*M-P的电荷转移作用. (4) HH构型中M对HOMO的贡献最大, PPh2py向M的电荷转移最强, 使M的负电荷最大, 故HH构型最易作为电子给体以M原子与第二个金属配位形成双核配合物.     

[M(en)3]2Sn2Se6(M=Mn,Zn)的制备及其热稳定性

用有机溶剂热生长技术(SolvothermalTechnique)制备过渡金属锰和锌硒化物[Mn(en)3]2Sn2Se6(Ⅰ),[Zn(en)3]2Sn2Se6(Ⅱ).用单晶X射线衍射技术对其进行晶体结构分析.[Zn(en)3]2Sn2Se6样品的热分析结果表明,该化合物的热分解分三步进行.光学性质测试表明它们是半导体材料,[Mn(en)3]2Sn2Se6的能带隙为1.76eV.[Zn(en)3]2Sn2Se6的能带隙为2.49eV.     

Thermal and calorimetric studies of M(IO3)2·6H2O and M(IO3)2·6D2O forM 2+=Ca2+ and Sr2+

Thermal and calorimetric studies were carried out on M(IO₃)₂·6H₂O and M(IO₃)₂·6D₂O forM ²⁺=Ca²⁺ and Sr²⁺, using DTA and DSC methods. The thermal behaviour of the ordinary and deuterated hydrates is outlined and the differences observed between them are discussed. The enthalpies of the phase transitions were determined. The H _f ^o for Ca(IO₃)₂·6H₂O, Ca(IO₃)₂·6H₂O(D₂O) and Sr(IO₃)₂·6H₂O(D₂O) were calculated from the H _deh data and comments are made on the isotope effect observed.

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Zusammenfassung Mittels DTA- und DSC-Methoden wurden Me(IO₃)₂·6H₂O und Me(IO₃)₂·6D₂O (mitMe ²⁺=Ca²⁺ und Sr²⁺) thermisch und kalorimetrisch untersucht. Es wird ein Überblick über das thermische Verhalten ordentlicher und deuterierter Hydrate gegeben, in dem auch die Unterschiede zwischen beiden diskutiert werden. Die Enthalpien der untersuchten Phasenumwandlungen wurden bestimmt. Aus den Daten für H_deh wurde H_f von Ca(IO₃)₂·6H₂O, Ca(IO₃)₂H₂O(D₂O) und Sr(IO₃)₂·6H₂O(D₂O) berechnet und Bemerkungen zum beobachteten Isotopeneffektes gemacht.

     

α-Na3M2(PO4)3 (M = Ti, Fe): absolute cationic ordering in NASICON-type phases

The structure of the fully ordered α-Na(3)Ti(2)(PO(4))(3) NASICON compound was elucidated using high-quality single-crystal data. The cation/vacancy distribution forms a homogeneous 3D arrangement and could represent the absolute cationic ordering available in the full Na(3)M(2)(PO(4))(3) series, as verified for M = Fe. For M = Ti, the reversible α → γ transition was observed at 85 °C, leading to the standard disordered R ?3c γ model. Through JPDF analysis, the most probable Na(+) zigzag M(2)-M(1) diffusion scheme was directly deduced using our accurate crystallographic data.     

Further studies of M3(μ3-O)(μ-X)3(μ-O2CCH3)3L3 (M=Mo,W) type clusters with nine core electrons

Four new compounds having nine cluster electrons and cores of the types Mo₃OCl₃, Mo₃OBr₃, and W₃OCl₃ are reported. Compound (1) prepared by reduction of [Bu₄N][Mo₃OCl₆(OAc)₃] in THF with metallic zinc, was shown by X-ray crystallography to be Mo₃OCl₄(OAc)₃ (THF)₂ (1). It forms crystals in space groupP2₁ with unit cell dimensionsa=9.472(2) Å,b=13.546(4) Å,c=9.652(2) Å, =101.70(2)°,V=1201(1) Å₃,Z=2. The [Mo₃(₃-O)(-Cl)₃]⁴⁺ core is surrounded by three -O₂CCH₃ anions, one Cl^–, and two THF and has Mo-Mo distances of 2.620(1) Å, 2.613(1) Å, and 2.530(1) Å, with the shortest bond between the two Mo atoms to which the THF molecules are coordinated. Compounds [Bu₄N]₂ [Mo₃OBr₆(O₂CCH₃)₃] · Me₂CO, (2) and [Mo₃OBr₃(O₂CCH₃)₃(PMe₃)₃]₃ · BF₄, (3) are the first two nine-electron Mo₃ species with a [Mo₃(₃-O) Br₃]⁴⁺ core. Both were obtained by zinc reduction of [Mo₃OBr₆(O₂CCH₃)₃]^– in the presence of (NBu₄) Br (2) or PMe₃ and NaBF₄ (3), and each was characterized crystallographically. Compound (2) crystallized in space group Cc with unit cell dimensionsa=25.037(5) Å,b=12.827(2) Å,c=21.484(4) Å, =122.96(1)⁰,V=5790(3) ų,Z=4. While the anion has no crystallographically required symmetry, its virtual symmetry is C_3v . The Mo-Mo distances are 2.619(2) Å, 2.610(3) Å, 2.644(2) Å, with a mean value of 2.624[14] Å. Compound (3) crystallized in space groupP2₁/c with unit cell dimensionsa=10.846(2) Å,b=25.033(5) Å,c=12.641(5) Å, =94.74(2)⁰,V=3420(2) ų,Z=4. The cation occupies a general position but has virtual C_3v symmetry, with Mo-Mo distances of 2.601(2) Å, 2.610(2) Å, 2.627(2) Å, with a mean value of 2.613[14] Å. Thus the anionic and cationic Mo₃ clusters in (2) and (3), respectively, have average Mo-Mo distances that are equal within experimental error. Compound (4), [NEt₄]₂ [W₃OCl₆(O₂CCH₃)₃] is the first 9-electron compound of this type containing tungsten. It was prepared by reduction of [Et₄N][W₃OCl₆(OAc)₃] in benzene with Na/Hg. It crystallized in space groupP2₁2₁2₁ with unit cell dimensionsa=11.076(2) Å,b=14.345(2) Å,c=21.026(3) Å,V=3574(1) ų,Z=4. The anion resides on a general position but has virtual C_3v symmetry, with W-W distances of 2.577(1) Å, 2.612(1) Å, 2.584(1) Å and a mean value of 2.591[15] Å.     

The reversible adduct formation of group III trialkyls with relatively involatile phosphines; X-ray crystal structures of (Me3M)2·(Ph2PCH2)2 (M = Al,Ga, In) and (Me3Al)3·(Ph2PCH2CH2)2PPh

The following adducts of Group III trialkyls with phosphines have been prepared, either by direct reaction in hydrocarbon solution or by displacement of ether from the metal trialkyl etherate: Me₃M·PPh₃ (M = Ga, In); Me₃In·P(2-MeC₆H₄)₃; (R₃M)₂·(Ph₂PCH₂)₂ (R = Me, M = Al, Ga, In; R = Et, M = Ga, In; R = Buⁱ, M = Al); (Me₃M)₃·(Ph₂PCH₂CH₂)₂PPh (M = Al, Ga, In) and (Me₃M)₄·(Ph₂PCH₂CH₂PPhCH₂)₂ (M = Al, Ga, In). The compounds were analysed by ¹H and ³¹P NMR spectra of (Me₃M)₂·(Ph₂PCH₂)₂ (M = Ga, In) showed little change between 193 K and room temperature. Thermal dissociation of the adducts in vacuo gave the free metal trialkyl with no detectable contamination by the respective phosphine. Crystals of (Me₃M)₂·(Ph₂PCH₂)₂ (M = Al, Ga, In) are iso-structural and the molecules contain two distorted tetrahedral metals bridged by the (Ph₂PCH₂)₂; the MP distances are 2.544(4), 2.546(4) and 2.755(4) Å, respectively. The X-ray crystal structure of (Me₃Al)₃·(Ph₂PCH₂CH₂)₂PPh shows the molecule to contain distorted tetrahedral aluminium atoms bonded to each of the three phosphorus atoms, with AlP distances of 2.536(9) and 2.510(9) Å for the terminal and central moieties, respectively; the unit cell contains two such molecules plus one benzene molecule (the crystallizing solvent).     

M(bpy)2+3(M=Fe,Ru,Os)电子结构与相关性质

报导了对配合物Ｍ（ｂｐｙ）＾２＋３（Ｍ＝Ｆｅ,Ｒｕ,Ｏｓ）的量子化学密度泛函法研究的结果。Ｂ３ＬＹＰ／ＬａｎＬ２ＤＺ方法与基组的水平上进行计算,探讨Ｍ（ｂｐｙ）＾２＋３电子结构特征及相关性质,特别是中心原子对配合物的配位键长、光谱性质,电荷布局及化学稳定性等的影响规律,为该类配合物的合成,为分析光、电、催化作用机理提供理论参考。     

M(bpy)2+3(M=Fe,Ru,Os)电子结构与相关性质

报导了对配合物(M=Fe,Ru,Os)的量子化学密度泛函(DFT)法研究的结果.在B3LYP/LanL2DZ方法与基组的水平上进行计算,探讨的电子结构特征及相关性质,特别是中心原子对配合物的配位键长、光谱性质、电荷布居及化学稳定性等的影响规律,为该类配合物的合成,为分析光、电、催化作用机理提供理论参考.     

[Ru(NH3)6](MoO4)Cl·3H2O and [M(NH3)6](ReO4)3·2H2O (M = Ru, Ir). Synthesis and crystal structure

X-ray crystallographic analysis is used to determine the crystal structures of [Ru(NH₃)₆](MoO₄)Cl·3H₂O and [M(NH₃)₆](ReO₄)₃·2H₂O (M = Ru, Ir) complex salts. The features of the fragment packing are studied.     

ChemInform Abstract: Are Cyclogallenes (M2(GaH)3) (M: Li,Na, K) Aromatic?

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

Comparative study of crystal structures of [M(NH3)5NO2]XY and [M(NH3)5ONO]XY. Crystal structure of [Co(NH3)5NO2](NO3)2·0.25H2O

The crystal structure of [Co(NH₃)₅NO₂](NO₃)₂·0.25H₂O has been determined. Co₁N₈O_8.25H_15.5, a=7.582(3), c=10.331(3) Å, V=593.9(5) ų, d_calc=1.782 g/cm³ for Z=2, space group I 4mm (C _4v ⁹ , No. 107). The structure is of the island type. Complex (distorted octahedral) cations are bonded to the NO ₃ ^? anions by electrostatic forces. Crystallization water is located in the vicinity of the labile NO₂ group.     

Synthesis,structures, and properties of the niobium and tantalum telluride cubane clusters [M4(μ4-O)(μ3-Te)4(CN)12]6– (M = Nb or Ta)

The new cubane cluster complex K₆[Ta₄(₄-O)(₃-Te)₄(CN)₁₂]·KOH·4H₂O was prepared from a mixture of TaTe₄ and KCN by the high-temperature synthesis followed by crystallization from aqueous solutions. The compound was characterized by cyclic voltammetry, X-ray diffraction analysis, and IR, Raman, and electronic spectroscopy. A comparative study of the clusters [M₄(₄-O)(₃-Te)(CN)₁₂]^6– (M = Nb or Ta) containing the ₄-O ligands was carried out. These clusters are the first molecular chalcogenide cubane complexes of Group V metals.     

(CH~3)~3M/PH~3(M=Ga,In)体系的密度泛函研究

用密度泛函理论方法对Me~3M/PH~3(Me=CH~3,M=Ga,In)体系及相关的一些分子进行了计算,得到优化几何构型、振动基频、电荷分布等参数和可能发生的化学反应的能量。为了比较,对Me~3Ga/NH~3体系也做了相应的研究。计算结果表明反应中间体Me~3M·YH~3(Y=N,P)具有稳定的结构,其生成反应是放热的。Me~3M·YH~3中的M－Y键比较弱,但当它们通过一个放热的分子内反应分解为Me~2MYH~2和CH~4后M－Y键大为增强。根据计算结果讨论了Me~3M/YH~3体系可能的热分解途径。由于Me~3M·YH~3单分子分解反应活化能比Me~3M中的M－C键直接均裂分解所需的能量要低得多,在有YH~3存在的情况下,Me~3M的热分解最有可能是首先形成Me~3M·YH~3及Me~2MYH~2中间体,然后进一步分解。用这一机理可以解释现有的实验事实。