Gd5-xYxTt4 (Tt = Si or Ge): effect of metal substitution on structure, bonding, and magnetism

A crystallographic study and theoretical assessment of the Gd/Y site preferences in the Gd 5- x Y x Tt 4 ( Tt = Si, Ge) series prepared by high-temperature methods is presented. All structures for the Gd 5- x Y x Si 4 system belong to the orthorhombic, Gd 5Si 4-type (space group Pnma). For the Gd 5- x Y x Ge 4 system, phases with x < 3.6 and x >or= 4.4 adopt the orthorhombic, Sm 5Ge 4-type structure. For the composition range of 3.6 相似文献   

Darstellung und elektronenmikroskopische Untersuchung neuer Verbindungen des Typs Ln3MO4Cl5 (Ln = La?Nd; M = Ge,V)

Preparation and Electronmicroscopic Investigation of New Compounds Ln₃MO₄Cl₅ (Ln = La? Nd; M = Ge, V) By heating mixtures of LnOCl, LnCl₃ und GeO₂ (2:1:1) in evacuated silica tubes (Pt-shells inside) the compounds Ln₃GeO₄Cl₅ (Ln = La? Nd) were prepared. The case that the temperature of preparation (La: T = 900°C, 8d; Ce: T = 800°C, 9d; Pr, Nd: T = 650°C, 13 d) had to be reduced from Ln = La to Ln = Nd indicates a decreasing thermodynamic stability in this direction. The compound La₃VO₄Cl₅ was prepared by heating (900°C, 8d) a mixture (2:1:1) of LaOCl, LaCl₃ and VO₂ and was investigated by electronmicroscopic techniques.     

Lithium dimer formation in the Li-conducting garnets Li(5+x)Ba(x)La(3-x)Ta2O12 (0 < x < or =1.6)

The garnet system Li(5+x)Ba(x)La(3-x)Ta2O12 shows an unprecedented Li+ content (x < or = 1.6) and short Li-Li distances of ca 2.44 A between majority occupied sites suggesting that the high Li+ mobility requires a complex cooperative mechanism.     

Solvothermal syntheses of [Ln(en)3(H2O)x(mu(3-x)-SbS4)] (Ln = La, x = 0; Ln = Nd, x = 1) and [Ln(en)4]SbS4.0.5en (Ln = Eu, Dy, Yb): a systematic study on the formation and crystal structures of new lanthanide thioantimonates(V)

New lanthanide thioantimonate(V) compounds, [Ln(en)3(H2O)x(mu(3-x)-SbS4)] (en = ethylenediamine, Ln = La, x = 0, Ia; Ln = Nd, x = 1, Ib) and [Ln(en)4]SbS4.0.5en (Ln = Eu, IIa; Dy, IIb; Yb, IIc), were synthesized under mild solvothermal conditions by reacting Ln2O3, Sb, and S in en at 140 degrees C. These compounds were classified as two types according to the molecular structures. The crystal structure of type I (Ia and Ib) consists of one-dimensional neutral [Ln(en)3(H2O)x(mu(3-x)-SbS(4))]infinity (x = 0 or 1) chains, in which SbS4(3-) anions act as tridentate or bidentate bridging ligands to interlink [Ln(en)3]3+ ions, while the crystal structure of type II (IIa, IIb, and IIc) contains isolated [Ln(en)4]3+ cations, tetrahedral SbS4(3-) anions, and free en molecules. A systematic investigation of the crystal structures of the five lanthanide compounds, as well as two reported compounds, clarifies the relationship between the molecular structure and the entity of the lanthanide(III) series, such as the stability of the lanthanide(III)-en complexes, the coordination number, and the ionic radii of the metals.     

Composition-structure relationships in polar intermetallics: experimental and theoretical studies of LaNi(1 + x)Al(6 - x) (x = 0.44)

A new ternary aluminide, LaNi(1 + x)Al(6 - x ) (x = 0.44), has been synthesized from La, Ni, and Al in sealed silica tubes. Its structure, determined by single-crystal X-ray diffraction, is tetragonal P4/mmm (No. 123) with Z = 1 and has the lattice parameters a = 4.200(8) and c = 8.080(8) angstroms. Refinement based on Fo2 yielded R1 = 0.0197 and wR2 = 0.020 [I > 2sigmaI]. The compound adopts a structure type previously observed in SrAu2Ga5 and EuAu2Ga5. The atomic arrangement is closely related to the one in BaAl4 as well as in other rare-earth gallide compounds such as LaNi0.6Ga6, HoCoGa5, Ce4Ni2Ga20, Ce4Ni2Ga17, Ce4NiGa18, and Ce3Ni2Ga15. This structure exhibits a large open cavity which may be filled by a guest atom. Band structure calculations using density functional theory have been carried out to understand the stability of this new compound.     

Electrospinning synthesis and luminescence properties of one-dimensional La(9.33)(SiO4)6O2: Ln3+ (Ln = Ce, Eu, Tb) microfibers

One-dimensional La(9.33)(SiO(4))(6)O(2): Ln(3+) (Ln = Ce, Eu, Tb) microfibers were fabricated by a simple and cost-effective electrospinning method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL) and low voltage cathodoluminescence (CL) as well as kinetic decay were used to characterize the resulting samples. SEM and TEM results indicated that the diameter of the microfibers annealed at 1000 °C for 3 h was 200-245 nm. The microfibers were further composed of fine and closely linked nanoparticles. La(9.33)(SiO(4))(6)O(2): Ln(3+) (Ln = Ce, Eu, Tb) phosphors showed the characteristic emission of Ce(3+) (5d → 4f), Eu(3+) ((5)D(0)→(7)F(J)) and Tb(3+) ((5)D(3,4)→(7)F(J)) under ultraviolet excitation and low-voltage electron beams (3-5 kV) excitation. An energy transfer from Ce(3+) to Tb(3+) was observed in the La(9.33)(SiO(4))(6)O(2): Ce(3+), Tb(3+) phosphor under ultraviolet excitation and low-voltage electron beam excitation. Luminescence mechanisms were proposed to explain the observed phenomena. Blue, red and green emission can be realized in La(9.33)(SiO(4))(6)O(2): Ln(3+) (Ln = Ce, Eu, Tb) microfibers by changing the doping ions. So the La(9.33)(SiO(4))(6)O(2): Ln(3+) (Ln = Ce, Eu, Tb) phosphors have potential applications in full-color field emission displays.     

Cation deficient layered Ruddlesden-Popper-related oxysulfides La2LnMS2O5 (Ln=La, Y; M=Nb, Ta)

The structures of the new oxysulfide Ruddlesden-Popper phases La2LnMS2O5 (Ln=La, Y; M=Nb, Ta) are reported together with an iodide-containing variant: La3-xNb1+xS2O5I2x (0相似文献   

Synthese und Struktur der Nitridoborat‐Nitride Ln4(B2N4)N (Ln = La,Ce) des Formeltyps Ln3+x(B2N4)Nx (x = 0, 1, 2)

Synthesis and Structure of Nitridoborate Nitrides Ln₄(B₂N₄)N (Ln = La, Ce) of the Formula Type Ln_3+x(B₂N₄)N_x (x = 0, 1, 2) The missing member of the formula type Ln_3+x(B₂N₄)N_x with x = 1 was synthesized and characterized for Ln = La and Ce. According to the single‐crystal X‐ray structure solution Ce₄(B₂N₄)N crystallizes in the space group C2/m (Z = 2) with the lattice parameters a = 1238.2(1) pm, b = 357.32(3) pm, c = 905.21(7) pm and β = 129.700(1)°. The anisotropic structure refinement converged at R1 = 0.039 and wR2 = 0.099 for all independent reflections. A powder pattern of La₄(B₂N₄)N was indexed isotypically with a = 1260.4(1) pm, b = 366.15(3) pm, c = 919.8(1) pm and β = 129.727(6)°. A structure rational for nitridoborates and nitridoborate nitrides containing B₂N₄ ions with the general formula Ln_3+x(B₂N₄)N_x with x = 0, 1, 2 is presented.     

Crystal growth, structure, and physical properties of LnCu2(Al,Si)5 (Ln = La and Ce)

LnCu(2)(Al,Si)(5) (Ln = La and Ce) were synthesized and characterized. These compounds adopt the SrAu(2)Ga(5) structure type and crystallize in the tetragonal space group P4/mmm with unit cell dimensions of a ≈ 4.2 ? and c ≈ 7.9 ?. Herein, we report the structure as obtained from single crystal X-ray diffraction. Additionally, we report the magnetic susceptibility, magnetization, resistivity, and specific heat capacity data obtained for polycrystalline samples of LnCu(2)(Al,Si)(5) (Ln = La and Ce).     

Crystal Structures of Ln（NO3）3（Ln=La,Yb）Complexes with 12—crown—4

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｓｏｆＬｎ（ＮＯ_３）_３（Ｌｎ＝Ｌａ，Ｙｂ）Ｃｏｍｐｌｅｘｅｓｗｉｔｈ１２－ｃｒｏｗｎ－４ＭａｏＪｉａｎｇ－Ｇａｏ；ＪｉｎＺｈｏｎｇ－Ｓｈｅｎｇ；ＹｕＦｅｎｇ－Ｌａｎ（ＬａｂｏｒａｔｏｒｙｏｆＲａｒｅＥａｒｔｈＣｈｅｍ...     

Synthese und Aufbau von (4-Picolinium)[LnCl4(H2O)3] (Ln = La,Ce, Pr,Nd)

Preparation and Crystal Structure of (4-Picolinium)[LnCl₄(H₂O)₃] (Ln = La, Ce, Pr, Nd) The complex water containing chlorides (4-Picolinium)[LnCl₄(H₂O)₃] (Ln = La, Ce, Pr, Nd) were prepared for the first time, and the crystal structures of (4-Picolinium)[LnCl₄(H₂O)₃] (Ln = La, Pr) were determined on single crystals by X-ray methods. The isotypic compounds crystallize with triclinic symmetry, space group P1 , Z = 2. Surprisingly there exist the dimeric complex anions [Ln₂Cl₈(H₂O)₆]^2? (Ln = La, Pr).     

KBi(2-x)Pbx (0 < x <or= 1): a Zintl phase evolving from a distortion of the cubic Laves-phase structure

The quasibinary system KBi(2-x)Pbx has been investigated, both experimentally and theoretically. Phases with compositions 0 < or = x < or = 1.2 were synthesized and structurally characterized by X-ray diffraction experiments. For low values of x (0 < or = x < 0.6), KBi(2-x)Pbx adopts the cubic Laves-phase structure MgCu2 (space group Fdm), which contains a rigid framework of corner-condensed symmetry-equivalent tetrahedra formed by randomly distributed Bi and Pb atoms. For compositions x > or = 0.6, these tetrahedra become alternately elongated and contracted. The distortion of the framework lowers the space-group symmetry to F43m (KBi(1.2)Pb(0.8), F43m, Z = 8, a = 9.572(1) A). Magnetometer measurements show that KBi2 (x = 0) is metallic and goes through a superconducting transition below 3.5 K. First principles calculations reveal that the Fd3m --> F43m distortion is largest for KBiPb (x = 1.0), which at the same time turns into a semiconductor. Thus, F43m KBiPb corresponds to a proper charge-balanced Zintl phase, K+[BiPb]-, with separated polyanionic tetrahedra, (Bi2Pb2)2-. However, it was not possible to prepare F43m KBiPb. Syntheses attempting to increase the Pb content in KBi(2-x)Pbx above x = 0.8 yielded additional, not yet characterized, ternary phases.     

K5LnLi2F10(Ln=La,Gd, Y)的合成和Ce^3^+在其中的发光

在Ar气氛中, 采用高温固相反应法合成了K5LnLi2F10(Ln=La, Ce, Gd, Y)化合物,X射线衍射图表明: 除K5YLi2F10外, 均具有与K5NdLi2F10(KNLF)相同的结构。计算了K5LnLi2F10(Ln=Ln, Ce, Gd)的晶胞参数和晶胞体积, 它们随着La^3^+, Ce^3^+,Gd^3^+的离子半径减小而有规律地减小, 测定了K5CexLn1-xLi2F10化合物的激发光谱和荧光光谱, 发现Ce^3^+的激发波长和发射波长随着La^3^+, Gd^3^+, Y^3^+离子的改变几乎不变, 并对这种现象进行了讨论。     

Two-phase synthesis of colloidal annular-shaped Ce(x)La(1-x)CO3OH nanoarchitectures assembled from small particles and their thermal conversion to derived mixed oxides

Undoped and cerium doped LaCO(3)OH annular-shaped nanoarchitectures with high specific surface area have been fabricated via the thermolysis of Ce(x)La(1-x)(oleate)(3) (x = 0-20 mol %) complexes in a toluene-water system containing tert-butylamine/oleylamine. The products exhibit 400 nm-sized monodisperse annular-shaped nanoarchitectures, which are constituted of 3-5 nm-sized primary particles. A possible mechanism of the reaction of Ce(x)La(1-x)(oleate)(3) and tert-butylamine for the formation of annular-shaped Ce(x)La(1-x)CO(3)OH nanoarchitectures is proposed. The thermal conversion of Ce(x)La(1-x)CO(3)OH to Ce(x)La(1-x)(CO(3))O(2) at 600 °C, to Ce(x)La(1-x)(OH)(3) at 800 °C, final to (Ce(x)La(1-x))(2)O(3-δ) at 900 °C were employed, while the original morphology was essentially unchanged. The dopant concentration was varied from 5 to 20 of cerium ions per LaCO(3)OH nanoparticle. The X-ray diffraction (XRD) results reveal that the cerium dopant could enter easily into the LaCO(3)OH structural lattice, whereas copper could unlikely enter into their lattice because of their large ionic radius difference. The cerium oxidation state was controlled by changing doping concentration. The X-ray photoelectron spectroscopy (XPS) results reveal that only one Ce(3+) oxidation state is in the as-synthesized Ce(x)La(1-x)CO(3)OH samples with cerium concentration ranging from 5 to 20 mol %, whereas both 3+ and 4+ ones coexisted in 20 mol % Ce:LaCO(3)OH structure. Remarkable luminescence emission intensity enhancement of 1.5-9.0 times were observed for Ce(x)La(1-x)CO(3)OH samples with cerium concentration ranging from 5 to 20 mol %, after doping with an undoped LaCO(3)OH.     

Acidities of 3d and 4f element sulfides are the key factor governing the type of phase diagram in MS-Ln2S3 (M = Mn,Fe; Ln = La-Lu) systems

An equation to calculate the acidity of simple sulfides and a relative acidity scale are proposed. A correlation between the type of phase diagram and the acid-base properties of constituent simple sulfides of the system is postulated. The similarity of the acid-base properties of simple sulfides provides that they have a eutectic-type diagram. Complex sulfides are formed when the difference between the relative acidities of simple sulfides exceeds some threshold value. The complex compounds formed in MnS-Ln₂S₃ (Ln = La, Ce) systems, namely Mn₂La₆S₁₁ and MnCe₂S₄, are classified with thiomanganates. The compounds formed in FeS-Ln₂S₃ (Ln = La, Ce, Pr) systems, namely FeLn₂S₄ (Ln = La, Ce) and FeLn₄S₇ (Ln = La-Pr), are classified with thioferrates. The strengthening of acidic properties in the Ln₂S₃ (Ln = La-Lu) series results in the formation of thiolanthanates: MnLn₂S₄ (Ln = Dy-Lu), MnLn₄S₇ (Ln = Tb-Tm), FeLu₂S₄, FeLn₄S₇ (Ln = Ho-Yb), and Fe₄Ln₂S₇ (Ln = Tm, Yb, Lu).     

Intermetallic compounds with near Zintl phase behavior: RE2Zn3Ge6 (RE = La, Ce, Pr, Nd) grown from liquid indium

A series of compounds has been discovered while investigating reactions of rare earth, transition metals, and Ge in excess indium. These compounds, RE2Zn3Ge6 (RE = La, Ce, Pr, Nd), are isostructural, crystallizing in the orthorhombic space group Cmcm with lattice parameters a = 5.9691(9) angstroms, b = 24.987(4) angstroms, and c = 5.9575(9) angstroms for La2Zn3Ge6, a = 5.9503(5) angstroms, b = 24.761(2) angstroms, and c = 5.9477(5) angstroms for the Ce analogue, a =5.938(2) angstroms, b = 24.708(8) angstroms, and c = 5.936(2) angstroms for Pr2Zn3Ge6, and a = 5.9094(7) angstroms, b = 24.619(3) angstroms, and c = 5.9063(5) angstroms for the Nd analogue. The structure is composed of PbO-like ZnGe layers and ZnGe4 cage layers and is related to the Ce4Zn8Ge(11-x) structure type. The bonding in the system can be rationalized using the Zintl concept resulting in a material that is expected to be a valence precise semiconductor, although its behavior is more consistent with it being a semimetal, making it an intermediate case. The results of band structure calculations and magnetic measurements of these compounds are discussed.     

Neue thermische Abbauprodukte von Ln2CeMO6Cl3 (M = Nb,Ta; Ln = La–Sm) – Darstellung von strukturverwandtem (La, Tb)3,5TaO6Cl4–x

Contributions on the Investigation of Inorganic Nonstoichiometric Compounds. XLV. New Thermal Decomposition Products of Ln₂CeMO₆Cl₃ – Preparation of Structure‐related (La, Tb)_3.5TaO₆Cl_4–x The thermal decomposition (T £ 900–1050°C) of Ln₂CeMO₆Cl₃ (M = Nb, Ta; Ln = La, Ce, Pr, Nd, Sm) leads to the formation of two mixed‐valenced phases (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ‘‘AB”︁”︁) and (Ln, Ce)_3.5MO₆Cl_4–x (phase ‘‘BB”︁”︁) and to the formation of chlorine according to redox‐reactions between Ce⁴⁺ and Cl^–. Single crystals of both phases (Ln, Ce)_3.25MO₆Cl_3.5–x (‘‘AB”︁”︁) and (Ln, Ce)_3.5MO₆Cl_4–x (‘‘BB”︁”︁) were obtained by chemical transport reactions using both powder of Ln₂CeMO₆Cl₃ (phase ‘‘A”︁”︁) and powder of (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ‘‘AB”︁”︁) as starting materials and chlorine (p{Cl₂; 298 K} = 1 atm) or HCl (p{HCl; 298 K} = 1 atm) as transport agent. A crystal of (La, Ce)_3.25NbO₆Cl_3.5–x (”︁AB”︁”︁) (space group: C2/m, a = 35.288(1) Å, b = 5.418(5) Å, c = 9.522(1) Å, β = 98.95(7)°, Z = 4) was investigated by x‐ray diffraction methods, a crystal of (Pr, Ce)_3.5NbO₆Cl_4–x (”︁BB”︁”︁) was investigated by synchrotron radiation (λ = 0.56 Å) diffraction methods. The lattice constants are a = 18.863(6) Å, b = 5.454(5) Å, c = 9.527(6) Å, β = 102.44(3)° and Z = 4. Structure determination in the space group C2/m (No. 12) let to R1 = 0.0313. Main building units are NbO₆‐polyhedra with slightly distorted trigonally prismatic environment for Nb and chains of face‐sharing Cl₆‐octahedra along [010]. The rare earth ions are coordinated by chlorine and oxygen atoms. These main structure features confirmed the expected relation to the starting material Ln₂CeMO₆Cl₃ (phase ”︁A”︁”︁) and to (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ”︁AB”︁”︁).     

Isolation of the new cubic phases RE4FeGa(12-x)Ge(x) (RE = Sm,Tb; x = 2.5) from molten gallium: single-crystal neutron diffraction study of the Ga/Ge distribution

The compounds RE4FeGa(12-x)Ge(x) (RE = Sm, Tb) were discovered in reactions employing molten Ga as a solvent at 850 degrees C. However, the isostructural Y4FeGa(12-x)Ge(x) was prepared from a direct combination reaction. The crystal structure is cubic with space group Imm, Z = 2, and a = 8.657(4) A and 8.5620(9) A for the Sm and Tb analogues, respectively. Structure refinement based on full-matrix least squares on F(o)2 resulted in R1 = 1.47% and wR2 = 4.13% [I > 2(I)] for RE = Sm and R1 = 2.29% and wR2 = 7.12% [I > 2(I)] for RE = Tb. The compounds crystallize in the U4Re7Si6 structure type, where the RE atoms are located on 8c (1/4, 1/4, 1/4) sites and the Fe atoms on 2a (0, 0, 0) sites. The distribution of Ga and Ge in the structure, investigated with single-crystal neutron diffraction on the Tb analogue, revealed that these atoms are disordered over the 12d (1/4, 0, 1/2) and 12e (x, 0, 0) sites. The amount of Ga/Ge occupying the 12d and 12e sites refined to 89(4)/11 and 70(4)/30%, respectively. Transport property measurements indicate that these compounds are metallic conductors. Magnetic susceptibility measurements and M?ssbauer spectroscopy performed on the Tb analogue show a nonmagnetic state for Fe, while the Tb atoms carry a magnetic moment corresponding to a mu(eff) of 9.25 mu(B).     

Crystal structure, chemical bonding, and phase relations of the novel compound Co4Al(7+x)Si(2-x) (0.27 < or = x < or = 1.05)

The title compound was detected and characterized during a systematic study of the Al-rich part of the Co-Al-Si system. The crystal structure was established via single-crystal X-ray diffraction. It represents a new type of structure of intermetallic compounds (Pearson symbol mC26, space group C2/m). The homogeneity range of the phase Co4Al(7+x)Si(2-x) (0.27(3) < or = x < or = 1.05(2)) and equilibria with neighboring phases were studied by electron probe microanalysis (EPMA) and X-ray powder diffraction. The lattice parameters of the compound were found to vary between Al-poor and Al-rich composition (a = 11.949(1)-12.042(1) A, b = 3.9986(4)-4.0186(4) A, c = 7.6596(8)-7.6637(9) A, and beta = 106.581(7)-106.140(7) degrees). A partial disorder caused by the Al/Si substitution in one of the five main group element positions was found, and different ordering models yielding different Al/Si occupation motifs and different distributions of interatomic distances are discussed in detail. Chemical bonding analysis with the electron localization function (ELF) reveals a covalently bonded Al/Si network and rather ionic interactions between Co and the network.     

Two new groups of homoleptic rare earth pyridylbenzimidazolates: (NC12H8(NH)2)[Ln(N3C12H8)4] with Ln = Y,Tb, Yb,and [Ln(N3C12H8)2(N3C12H9)2][Ln(N3C12H8)4](N3C12H9)2 with Ln = La,Sm, Eu

The compounds (NC(12)H(8)(NH)(2))[Ln(N(3)C(12)H(8))(4)], Ln = Y, Tb, Yb, and [Ln(N(3)C(12)H(8))(2)(N(3)C(12)H(9))(2)][Ln(N(3)C(12)H(8))(4)](N(3)C(12)H(9))(2), with Ln = La, Sm, Eu, were obtained by reactions of the group 3 metals yttrium and lanthanum as well as the lanthanides europium, samarium, terbium, and ytterbium with 2-(2-pyridyl)-benzimidazole. The reactions were carried out in melts of the amine without any solvent and led to two new groups of homoleptic rare earth pyridylbenzimidazolates. The trivalent rare earth atoms have an eightfold nitrogen coordination of four chelating pyridylbenzimidazolates giving an ionic structure with either pyridylbenzimidazolium or [Ln(N(3)C(12)H(8))(2)(N(3)C(12)H(9))(2)](+) counterions. With Y, Eu, Sm, and Yb, single crystals were obtained whereas the La- and Tb-containing compounds were identified by powder methods. The products were investigated by X-ray single crystal or powder diffraction and MIR and far-IR spectroscopy, and with DTA/TG regarding their thermal behavior. They are another good proof of the value of solid-state reaction methods for the formation of homoleptic pnicogenides of the lanthanides. Despite their difference in the chemical formula, both types (NC(12)H(8)(NH)(2))[Ln(N(3)C(12)H(8))(4)], Ln = Y (1), Tb (2), Yb (3), and [Ln(N(3)C(12)H(8))(2)(N(3)C(12)H(9))(2)][Ln(N(3)C(12)H(8))(4)](N(3)C(12)H(9))(2), Ln = La (4), Sm (5), Eu (6), crystallize isotypic in the tetragonal space group I4(1). Crystal data for (1): T = 170(2) K, a = 1684.9(1) pm, c = 3735.0(3) pm, V = 10603.5(14) x 10(6) pm(3), R1 for F(o) > 4sigma(F(o)) = 0.053, wR2 = 0.113. Crystal data for (3): T = 170(2) K, a = 1683.03(7) pm, c = 3724.3(2) pm, V = 10549.4(14) x 10(6) pm(3), R1 for F(o) > 4sigma(F(o)) = 0.047, wR2 = 0.129. Crystal data for (5): T = 103(2) K, a = 1690.1(2) pm, c = 3759.5(4) pm, V = 10739(2) x 10(6) pm(3), R1 for F(o) > 4sigma(F(o)) = 0.050, wR2 = 0.117. Crystal data for (6): T = 170(2) K, a = 1685.89(9) pm, c = 3760.0(3) pm, V = 10686.9(11) x 10(6) pm(3), R1 for F(o) > 4sigma(F(o)) = 0.060, wR2 = 0.144.