BaLn2Se4 (Ln = Er,Tm and Yb)

The compounds BaLn₂Se₄ (Ln = rare‐earth metal = lanthanide = Er, Tm and Yb), namely barium di(erbium/thulium/ytterbium) tetraselenide, crystallize in the orthorhombic space group Pnma in the CaFe₂O₄ structure type. In this structure type, all atoms possess m symmetry. The Ln atoms are octahedrally coordinated by six Se atoms. A three‐dimensional channel structure is formed by the corner‐ and edge‐sharing of these LnSe₆ octahedra. The Ba atoms are coordinated to eight Se atoms in a bicapped trigonal–prismatic arrangement, and they occupy the channels of the three‐dimensional framework.     

RE[CH2（CH2）4CONC4H9]3（NO3）3（RE=La,Dy）的合成和晶体结构

采用Ｘ－射线四园衍射仪测定了Ｄｙ「Ｃｈ２（ＣＨ２）４ＣＯＮＣ４Ｈ９」３（ＮＯ３）３和Ｌａ「ＣＨ２（ＣＨ２）４ＣＯＮＣ４Ｈ３」３（ＮＯ３）３的晶体结构。两个配合物具有相似的结构，均属单斜晶系，空间群为Ｐ２１／ｃ。晶体参数：Ｄｙ「Ｌａ」：ａ＝１．８５６４（３）「１．８５６４（２）」ｎｍ，ｂ＝０．９７６９（２）「０．９８３４（１）」ｎｍ，ｃ＝２．１８６３（６）「２．２００３８（７）」ｎｍ，β＝９６．０８     

Ln4(CH2)4 cubane-type rare-earth methylidene complexes consisting of "(C5Me4SiMe3)LnCH2" units (Ln = Tm, Lu)

Tetranuclear cubane-type rare-earth methylidene complexes consisting of four "Cp'LnCH(2)" units, [Cp'Ln(μ(3)-CH(2))](4) (4-Ln; Ln = Tm, Lu; Cp' = C(5)Me(4)SiMe(3)), have been obtained for the first time through CH(4) elimination from the well-defined polymethyl complexes [Cp'Ln(μ(2)-CH(3))(2)](3) (2-Ln) or mixed methyl/methylidene precursors such as [Cp'(3)Ln(3)(μ(2)-Me)(3)(μ(3)-Me)(μ(3)-CH(2))] (3-Ln). The reaction of the methylidene complex 4-Lu with benzophenone leads to C═O bond cleavage and C═C bond formation to give the cubane-type oxo complex [Cp'Lu(μ(3)-O)](4) and CH(2)═CPh(2), while the methyl/methylidene complex 3-Tm undergoes sequential methylidene addition to the C═O group and ortho C-H activation of the two phenyl groups of benzophenone to afford the bis(benzo-1,2-diyl)ethoxy-chelated trinuclear complex [Cp'(3)Tm(3)(μ(2)-Me)(3){(C(6)H(4))(2)C(O)Me}] (6-Tm).     

Preparation and crystal structure of the Isotypic Carbides Ln4Ni2C5 (Ln = Er,Tm, Yb and Lu)

The title compounds were prepared from the elemental components in a lithium flux. Their crystal structure was determined for the ytterbium compound from single-crystal X-ray data. It is orthorhombic, Pmm2, a = 352.88(6) pm, b = 1 143.0(3) pm, c = 366.16(6) pm, Z = 1, R = 0.020 for 1 261 structure factors and 29 variable parameters. The structure may be viewed as an intergrowth of slabs consisting of the CeNiC₂ and the ScC (NaCl type) structures. It thus contains C₂ pairs with a C? C distance of 138(1) pm and isolated carbon atoms. Together with the nickel atoms the C₂ pairs form one-dimensionally infinite building elements [Ni₂C₄]_n. The fifth carbon atom is octahedrally coordinated by ytterbium atoms. Accordingly the compound may be rationalized to a first approximation with the formula (Yb³⁺)₄[Ni₂C₄^8?]C^4?. Yb₄Ni₂C₅ shows Curie-Weiss behaviour with a magnetic moment of μ_exp = 4.44 μ_B per ytterbium atom in good agreement with the theoretical moment of μ_eff = 4.53 μ_B for Yb³⁺.     

(NH2CH2CH2NH3)4[WⅤO2(OC6H4O)2]2(NH3CH2CH2NH3)·H2O的合成、晶体结构、EPR以及与同构物的比较

Cis-dioxo-catecholatotungsten(Ⅴ) complex (NH₂CH₂CH₂NH₃)₄[W^ⅤO₂(OC₆H₄O)₂]₂(NH₃CH₂CH₂NH₃)·H₂O (1) was synthesized at room temperature by the reaction of tetrabutyl ammonium decatungstate with catechol in the mixed solvent of CH₃OH, CH₃CN and NH₂CH₂CH₂NH₂. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P2₁/c,a=0.712 8(3) nm, b=3.082 3(11) nm, c=0.982 8(4) nm, β=102.639(6)°, V=2.106 8(14) nm³, Z=2, R₁=0.062 8, wR₂=0.183 7. Compared the complex with its analogous complexes (NH₂CH₂CH₂NH₃)₃[Mo^ⅤO₂(OC₆H₄O)₂], it is found that the coordination structure of W have no changes in the processing of electron transfer of tungsten-containing enzymes from the result of the similarity of the EPR spectra of the complexes and flavoenzyme from milk. CCDC: 272937.     

[(NH2CH2CH2NH3)2WⅥO2(NHC6H4NH)2]2(NH2CH2CH2NH2)·H2O配合物的合成与晶体结构

Cis-dioxo-tungsten(Ⅵ) complex, (NH₂CH₂CH₂NH₂)[(NH₂CH₂CH₂NH₃)₂W^ⅥO₂(NHC₆H₄NH)₂]₂·H₂O is synthesized at room temperature by the reaction of sodium tungstate with o-phenylenediamine. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P2₁/ c, a=0.712 8(2) nm, b=3.081 1(10) nm, c=0.981 9(3) nm, β=102.615(4)°, V=2.104 4(11) nm³, Z=2, μ=55.26 cm^-1, F(000)=1 176. Compared the complex with its analogous biomimetic complexes of the cofactor of molybdoenzymes and tungstoenzymses, it is found that the variance of the coordination atoms and the metal ions center have no influence on the coordination feature, and exhibits distored octahedral coordination with cis-dioxo o-phenylenediamine. CCDC: 252834.     

Coordination polyhedra LnOn (Ln = Er, Tm, Yb, Lu) in crystal structures

The Voronoi-Dirichlet polyhedra (VDP) and the method of intersecting spheres were used to analyze crystal structures of 728 compounds containing 976 crystallographically non-equivalent sorts of LnO_n polyhedra (Ln = Er, Tm, Yb, Lu). The Ln C.N. vary from 3 to 10, and 14 sorts of coordination polyhedra are present in the structures. Despite the great diversity of C.N., the volume of the VDP was found to depend only on the nature of the Ln atom and its valence state.     

新型三维开放骨架稀土硫酸盐[Ln4(H2O)4(SO4)10](C4N2H12)4(H2O)4(Ln=Gd,Eu)的合成、结构及荧光性质

以哌嗪为模板剂,在水-乙醇混合溶剂体系中溶剂热合成了两个具有三维开放骨架结构的稀土硫酸盐[Ln4(H2O)4(SO4)10](C4N2H12)4(H2O)4（Ln = Gd,化合物1和Eu,化合物2）,并对其进行了结构表征、热重以及荧光光谱分析. 单晶结构解析表明,化合物1和2属于同构异质,均结晶于单斜晶系,P21/c空间群,化合物1,a = 19.691(3) ?,b = 19.249(3) ?,c = 13.186(2) ?,β = 92.33(0)o,V = 4993.5(1) ?3, Z =4. 化合物2,a = 19.7233(8) ?,b = 19.2791(8) ?,c = 13.2095(5) ?,β = 92.329(1)o,V = 5018.7(3) ?3, Z =4. 两个化合物在ab平面上由SO4,GdO8和GdO9多面体共边或共角交错连接形成含有八元环和十六元环的二维层状结构,该二维层沿c方向平行排列,相邻层通过SO4四面体相连形成具有孔道的三维开放骨架结构,其孔道之中包含平衡骨架负电荷的质子化哌嗪分子. 化合物2的固体荧光光谱分析显示其在397nm激发波长下,表现出典型的Eu3+发光性质.       

Unimolecular reactions of the isolated immonium ions CH3CH = NH+C4H9, CH3CH2Ch = NH+C4H9 and (CH3)2C = NH+C4H9

The reactions of ten metastable immonium ions of general structure R¹R²C?NH⁺C₄H₉ (R¹ = H, R² = CH₃, C₂H₅; R¹ = R² = CH₃) are reported and discussed. Elimination of C₄H₈ is usually the dominant fragmentation pathway. This process gives rise to a Gaussian metastable peak; it is interpreted in terms of a mechanism involving ion-neutral complexes containing incipient butyl) cations. Metastable immonium ions ontaining an isobutyl group are unique in undergoing a minor amount of imine (R¹R²C?NH) loss. This decomposition route, which also produces a Gaussian metastable peak, decreases in importance as the basicity of the imine increases. The correlation between imine loss and the presence of an isobutyl group is rationalized by the rearrangement of the appropriate ion-neutral complexes in which there are isobutyl cations to the isomeric complexes containing the thermodynamically more stable tert-butyl cations. A sizeable amount of a third reaction, expulsion of C₃H₆, is observed for metastable n-C₄H₉ ⁺NH?CR¹R² ions; in contrast to C₄H₈ and R¹R²C?NH loss, C₃H₆ elimination occurs with a large kinetic energy release (40–48 kJ mol^?1) and is evidenced by a dish-topped metastable peak. This process is explained using a two-step mechanism involving a 1,5-hydride shift, followed by cleavage of the resultant secondary open-chain cations, CH₃CH⁺ CH₂CH₂NHCHR¹R².     

Synthesis and thermal decomposition of (NH4)2[MIIIF5(H2O) (M=Al,Fe and Cr)

Ammonium pentafluorometallate monohydrates were prepared by different methods and characterized by chemical analysis, IR spectrometry and X-ray diffraction. Unit cell parameters were determined for the Fe and Cr compounds, which were found to be isostructural with the known Al compound. The IR spectra, X-ray diffraction patterns and lattice data on the compounds are very similar, and point to the existence of isolated [M^IIIF₅(H₂O)]^2– octahedra. The water is coordinated to theM ^III cation.Dehydration and thermal decomposition were investigated by thermal analysis (TG, DTG, DTA) on the Q-derivatograph and by high-temperature X-ray diffraction. Different dehydration temperatures and products were found, depending on the nature of theM ^III cation. NH₄F is liberated in several steps (Al or Fe) or continuously (Cr), leading to the formation ofM ^III fluorides.

---

Zusammenfassung Ammoniumpentafluormetallat-monohydrate (NH₄)₂MeF₅ · H₂O (M=Fe, Al, Cr) wurden nach verschiedenen Methoden präpariert und durch chemische Analyse, IR-Spektren und Röntgenbeugung charakterisiert. Die Elementarzellen-Parameter der mit der Al-Verbindung isostrukturellen Fe- und Cr-Verbindung wurden ermittelt. IR-Spektren, Röntgenbeugungsdiagramme und Gitterdaten aller drei Verbindungen sind einander sehr ähnlich und beweisen das Vorliegen isolierter [M^IIIF₅(H₂O)]^2– -Oktaeder, in denen Wasser mit dem Kation koordiniert ist. Entwässerung und thermische Zersetzung wurden durch simultane TG-DTG-DTA und durch Hochtemperatur-Röntgenbeugung untersucht. Abhängig vom KationM ^III werden unterschiedliche Reaktionsprodukte und -temperaturen gefunden. Unter kontinuierlicher (M=Cr) oder schrittweiser Freisetzung von NH₄F (Fe, Al) wird das jeweilige Fluorid M^IIIF₃3 gebildet.

---

, . , , . , . [M^IIIF₅(H₂O)]^2–, ^III. Q- , , . , M^III. , , — , .

     

Methanesulfonates of high-valent metals: syntheses and structural features of MoO2(CH3SO3)2, UO2(CH3SO3)2, ReO3(CH3SO3), VO(CH3SO3)2, and V2O3(CH3SO3)4 and their thermal decomposition under N2 and O2 atmosphere

Oxide methanesulfonates of Mo, U, Re, and V have been prepared by reaction of MoO(3), UO(2)(CH(3)COO)(2)·2H(2)O, Re(2)O(7)(H(2)O)(2), and V(2)O(5) with CH(3)SO(3)H or mixtures thereof with its anhydride. These compounds are the first examples of solvent-free oxide methanesulfonates of these elements. MoO(2)(CH(3)SO(3))(2) (Pbca, a=1487.05(4), b=752.55(2), c=1549.61(5) pm, V=1.73414(9) nm(3), Z=8) contains [MoO(2)] moieties connected by [CH(3)SO(3)] ions to form layers parallel to (100). UO(2)(CH(3)SO(3))(2) (P2(1)/c, a=1320.4(1), b=1014.41(6), c=1533.7(1) pm, β=112.80(1)°, V=1.8937(3) nm(3), Z=8) consists of linear UO(2)(2+) ions coordinated by five [CH(3)SO(3)] ions, forming a layer structure. VO(CH(3)SO(3))(2) (P2(1)/c, a=1136.5(1), b=869.87(7), c=915.5(1) pm, β=113.66(1)°, V=0.8290(2) nm(3), Z=4) contains [VO] units connected by methanesulfonate anions to form corrugated layers parallel to (100). In ReO(3)(CH(3)SO(3)) (P1, a=574.0(1), b=1279.6(3), c=1641.9(3) pm, α=102.08(2), β=96.11(2), γ=99.04(2)°, V=1.1523(4) nm(3), Z=8) a chain structure exhibiting infinite O-[ReO(2)]-O-[ReO(2)]-O chains is formed. Each [ReO(2)]-O-[ReO(2)] unit is coordinated by two bidentate [CH(3)SO(3)] ions. V(2)O(3)(CH(3)SO(3))(4) (I2/a, a=1645.2(3), b=583.1(1), c=1670.2(3) pm, β=102.58(3), V=1.5637(5) pm(3), Z=4) adopts a chain structure, too, but contains discrete [VO]-O-[VO] moieties, each coordinated by two bidentate [CH(3)SO(3)] ligands. Additional methanesulfonate ions connect the [V(2)O(3)] groups along [001]. Thermal decomposition of the compounds was monitored under N(2) and O(2) atmosphere by thermogravimetric/differential thermal analysis and XRD measurements. Under N(2) the decomposition proceeds with reduction of the metal leading to the oxides MoO(2), U(3)O(7), V(4)O(7), and VO(2); for MoO(2)(CH(3)SO(3))(2), a small amount of MoS(2) is formed. If the thermal decomposition is carried out in a atmosphere of O(2) the oxides MoO(3) and V(2)O(5) are formed.     

The thermal characteristics of potassium oxalato lanthanates: K3LnOx3 · n H2O (Ln=La−Tb) and K8Ln2Ox7 · 14 H2O (Ln=Tb−Yb,Y)

The title compounds were studied by TG, DTA, DSC, IR and absorption spectroscopy. The complexes go through dehydration (70–200°C), an irreversible exothermic process (in air or N₂ atmosphere, 250–300°C) and decomposition to a mixture of oxides and carbonates (385–700°C). The exothermic process occurs without weight loss and corresponding heats of reaction fall in the range 0–26 kJ/mol. The absorption spectrum of the Nd complex in the range 5000–6000 Å was employed to monitor perturbations in the coordination sphere of Nd³⁺ arising from the exothermic process. Involvement of the Nd³⁺ cation is implied and the heats of reaction show a close relationship to the radii of Ln³⁺. The interpretation of these data was made with the aid of valuable structural information obtained previously.     

Synthesis and characterisation of TlLn(SO4)2·xH2O (Ln=La-Tb)

The compounds TlLn(SO₄)₂·2H₂OLn=La, Ce, Pr, Nd and Tl[Ln(SO₄)₂(H₂O)₃]·H₂OLn=Nd, Sm, Eu, Gd, Tb have been isolated from aqueous solutions of the corresponding sulfates. The dihydrates are all isomorphous and crystallize monoclinic, space groupP2₁/n,Z=4. The compounds which belong to the second type are also isomorphous and crystallize in monoclinic space groupP 2₁/c withZ=4.The dehydration has been studied by thermogravimetry, differential scanning calorimetry and isothermal weight change determination. The dihydrates dehydrate in a single step. For the tetrahydrates the reaction is more complex, however no intermediate phases could be isolated.The unit cell parameters, the dehydration temperatures and the dehydration enthalpies are correlated to the ionic radii ofLn ³⁺.

---

Synthese und Charakterisierung von TlLn(SO₄)₂·xH₂O (Ln=La-Tb)

Zusammenfassung Die Verbindungen TlLn(SO₄)₂·2H₂OLn=La, Ce, Pr, Nd und Tl[Ln(SO₄)₂(H₂O)₃]·H₂OLn=Nd, Sm, Eu, Gd, Tb wurden aus wäßrigen Lösungen der entsprechenden Sulfate isoliert. Die Dihydrate sind alle isomorph und kristallisieren monoklin, RaumgruppeP 2₁/n,Z=4. Die Verbindungen des zweiten Typs sind auch isomorph und kristallisieren in der monoklinen RaumgruppeP 2₁/c mitZ=4.Die Dehydration wurde mit TG, DSC und dem isothermalen Gewichtsverlust untersucht. Die Entwässerung der Dihydrate verläuft in einer Stufe, die von Tetrahydraten aber in mehreren Stufen mit keiner isolierbaren Zwischenphase.Die Gitterkonstanten, die Dehydratations-Temperaturen und -Enthalpien wurden mit den Ionenradien vonLn ³⁺ korreliert.

     

席夫碱稀土配合物(3,5-t-Bu_2-2-OC_6H_2CH=N-8-C_9H_6N)_3Ln(Ln=Eu,Yb)的合成及晶体结构

以席夫碱钠盐[NaL(THF)]2(L=3,5-t-Bu2-2-OC6H2CH=N-8-C9H6N)(1)为前体,与无水LnCl3(Ln=Eu,Yb)按物质的量比3∶2在四氢呋喃体系中室温反应24 h,高产率地得到均配型席夫碱稀土配合物LnL3[Ln=Eu(2),Yb(3)].两个配合物都通过了元素分析、红外光谱及单晶X射线衍射表征,其中配合物2属于三斜晶系,P 1空间群,a=1.28670(14)nm,b=1.32775(14)nm,c=2.3254(2)nm,α=93.435(2)°,β=96.487(2)°,γ=112.692(2)°.配合物3属于单斜晶系,P21/c空间群,a=1.72004(9)nm,b=1.81911(9)nm,c=2.85093(15)nm,β=106.376(1)°.     

Ordered phases in Ln-S systems (Ln = Tm, Yb)

The structures of known defect ordered phases present in Ln-X systems (50-60 at.% X) are analyzed and systematized according to the concentration of cation vacancies as cubic and trigonal phases. The structures of the defect phases present in Ln-X systems (X = S, Se, Te) are modeled by ordering the cation vacancies along (111) in the basic NaCl structure (ao~5.6 A). The following structures were derived: α-NaFeO₂ and defect structures on its basis Sc_I.37[]_0.62S₂, CaHo₂Se₄ (a_hex = 2a₀√2/4, Chex = 2a₀√3 a_R = 2a₀√6/4, α_R = 33?), CaY₂Se₄ ( a_hex = 2a₀√2/2, c_hex = 2a₀√3: a_R = 2a₀√2/2, α_R = 60?), and EuEr₂Te₄ ( a_hex = a₀√6/2, c_hex = a₀√3 ). All these phases except the last one may be obtained from NaCl by using direct rhombohedral distortion, and the last phase is a superstructure of a rhombohedral cell with parameters a_R ~ 2a₀√2/2, α_R ~ 60?. The solutionmelt method (eutectic mixture 1.86NaCl-NiCl₂ with Tm(Yb):S from 1:3 to 1:10) was used to synthesize poly crystalline samples containing two new trigonal defect phases of possible composition Ln_1+x+[]_1-xS² with cell parameters a = 3.835(7), c = 18.89(4) Å and a = 3.83(3), c= 18.78(1) A (I) and also a = 7.749(7), c = 18.46(3) Å and a = 7.74(1), c = 18.41(3) A (II) in Tm-S and Yb-S systems, respectively. It is maintained that the crystal structure of phase I with x ~ 0.37 (space group R3m) is derived from the NaCl structure and is close to Sc_1.37[]_0.63S₂ and the crystal structure of phase II with x~0.34 (space group P3cl) is derived from the Ni As structure. Possible ordering of cations with different formal charges accompanied by variation of symmetry is discussed.     

The thermal decomposition of (NH4)[VO(O2)2(NH3)]

The compound, (NH₄)[VO(O₂)₂(NH₃)], thermally decomposes to ammonium metavanadate, which then decomposes to vanadium pentoxide. Using a heating rate of 5 deg·min^–1, the first decomposition step occurs between 74° and 102°C. The transformation degree dependence of the activation energy (-E) is shown to follow a decreasing convex form, indicating that the first decomposition step is a complex reaction with a change in the limiting stage of the reaction. Infrared spectra indicated that the decomposition proceeds via the gradual reduction of the ratio of the (NH₄)₂O to V₂O₅ units from the original 11 ratio in ammonium metavanadate, which may be written as (NH₄)₂O·V₂O₅, to V₂O₅.The assistance of Professor A. M. Heyns (University of Pretoria) and Professor K. L. Range (University of Regensburg) is gratefully acknowledged as well as the financial assistance of the University of Pretoria and the FRD.     

配合物[NH3(CH2)4NH3]Co(hedpH2)(H2O)2的水热合成与表征(hedpH4=1-羟亚乙基二膦酸)

采用水热合成法以丁二胺作为模板剂合成了钴的有机二膦酸超分子化合物[NH3(CH2)4NH3]Co(hedpH2)2(H2O)2 [hedpH4 = 1-羟亚乙基二膦酸, CH3C(OH)(PO3H2)2]。用元素分析、红外光谱、紫外-可见光谱、热重分析以及单晶结构解析对其进行了表征。该化合物的化学式为:C8H30N2CoO16P4,Mr = 593.15,晶体属单斜晶系,空间群C2/c,晶胞参数a = 16.128(2), b = 12.427(1), c = 12.610(2) ? b = 121.389(9), V = 2157.3(4) 3, Z = 4, Dc = 1.826 g/cm3, m(MoKa) = 1.172 mm-1, F(000) = 1228。结构用直接法解出,最终偏离因子R = 0.0285, wR = 0.0747。该化合物的结构包含单核的Co(hedpH2)2- 阴离子,阴离子之间通过氢键连结形成具有空隙的三维超分子骨架结构,双质子化的丁二胺分子位于空隙中。