Contribution of disulfide S2(2-) anions to the crystal and electronic structures in ternary sulfides, Ba12In4S19, Ba4M2S8 (M=Ga, In)

Three semiconducting ternary sulfides have been synthesized from the mixture of elements with about 20% excess of sulfur (to establish oxidant rich conditions) by solid-state reactions at high temperature. Ba(12)In(4)S(19) ≡ (Ba(2+))(12)(In(3+))(4)(S(2-))(17)(S(2))(2-), 1, crystallizes in the trigonal space group R ?3 with a = 9.6182(5) ?, b = 9.6182(5) ?, c = 75.393(7) ?, and Z = 6, with a unique long period-stacking structure of a combination of monometallic InS(4) tetrahedra, linear dimeric In(2)S(7) tetrahedra, disulfide S(2)(2-) anions, and isolated sulfide S(2-) anions that is further enveloped by Ba(2+) cations. Ba(4)In(2)S(8) ≡ (Ba(2+))(4)(In(3+))(2)(S(2-))(6)(S(2))(2-), 2, crystallizes in the triclinic space group P ?1? with a = 6.236(2) ?, b = 10.014(4) ?, c = 13.033(5) ?, α = 104.236(6)°, β = 90.412(4)°, γ = 91.052(6)°, and Z = 2. Ba(4)Ga(2)S(8) ≡ (Ba(2+))(4)(Ga(3+))(2)(S(2-))(6)(S(2))(2-), 3, crystallizes in the monoclinic P2(1)/c with a = 12.739(5) ?, b = 6.201(2) ?, c = 19.830(8) ?, β = 104.254(6)° and Z = 4. Compounds 2 and 3 represent the first one-dimensional (1D) chain structure in ternary Ba/M/S (M = In, Ga) systems. The optical band gaps of 1 and 3 are measured to be around 2.55 eV, which agrees with their yellow color and the calculation results. The CASTEP calculations also reveal that the disulfide S(2)(2-) anions in 1-3 contribute mainly to the bottom of the conduction bands and the top of valence bands, and thus determine the band gaps.     

Tetrafluoroaurate(III) der Lanthaniden M2F[AuF4]5 (M = Tb,Dy, Ho,Er)

Tetrafluoroaurates(III) of Lanthanoides M₂F[AuF₄]₅ (M = Tb, Dy, Ho, Er) Tetrafluoroaurates(III) M₂F[AuF₄]₅ with M = Tb, Dy, Ho, Er, all yellow, have been obtained. From single crystal data they crystallize triclinic, space group P1 -C¹_i (No. 2) with Tb: a = 1 194,34(7) pm, b = 798,46(6) pm, c = 902,02(7) pm, α = 89,033(7)°, β = 88,990(6)°, γ = 89,006(7)°; Dy: a = 1 191,66(9) pm, b = 796,33(8) pm, c = 899,65(9) pm, α = 88,956(8)°, β = 89,056(8)°, γ = 88,972(8)°; Ho: a = 1 189,06(10) pm, b = 795,46(6) pm, c = 896,81(7) pm, α = 88,912(8)°, β = 89,101(7)°, γ = 88,873(8)°; Er: a = 1 185,20(40), b = 793,98(14), c = 893,83(20), α = 88,751(23)°, β = 89,187(26)°, γ = 88,884(9)°     

Unusual nitro-coordination of europium(iii) and terbium(iii) with pyridinyl ligands

A new ligand family based on picoline, bipyridine and terpyridine containing a nitro moiety has been synthesized and its coordination and sensitization ability for lanthanide ions has been studied. Three new complexes were characterized by X-ray single crystal diffraction and all three show uncommon coordination of the nitro moiety to the lanthanide ion. , a terpyridine-nitro derivative with Tb(NO(3))(3), crystallizes in the orthorhombic space group Pbca with a = 15.125(3), b = 13.776(3), c = 18.716(4) ?, and V = 3899.8(13) ?(3) and is isostructural with its Eu(iii) analog () with cell parameters a = 15.1341(4), b = 13.7070(4), c = 18.8277(5) ?. , a tripodal amine with a nitro-derivatized pyridine with Eu(CF(3)SO(3))(3), crystallizes in the triclinic space group P1[combining macron] with a = 11.067(2), b = 11.633(2), c = 12.772(3) ?, α = 110.94(3), β = 97.49(3), γ = 91.42(3)° and V = 1518.1(5) ?(3). Finally, ligand , a bipyridine-nitro derivative, crystallizes in the orthorhombic space group P2(1)/n with a = 3.7128(3), b = 11.7806(8), c = 19.9856(14) ?, β = 92.925(2)° and V = 873.01(11) ?(3). All four ligands show sensitization of Eu(iii) and Tb(iii) luminescence.     

Fluoroplatinate(IV) der Lanthaniden LnF[PtF6]. (Ln = Pr,Sm, Gd,Tb, Dy,Ho, Er)

Fluoroplatinates(IV) of the Lanthanides LnF[PtF₆] (Ln = Pr, Sm, Gd, Tb, Dy, Ho, Er) For the first time fluorides LnF[PtF₆] (Ln = Pr, Sm, Gd, Tb, Dy, Ho, Er), all yellow have been obtained. From single crystal data they crystallize monoclinic, space group P2₁/n?C (No. 14), Z = 4, Pr: a = 1 125.77(19) pm, b = 559.04(7) pm, c = 910.27(17) pm, β = 107.29(1)°; Sm: a = 1 114.63(31) pm, b = 552.70(12) pm, c = 898.02(20) pm, β = 107.24(2)°; Gd: a = 1 112.12(15) pm, b = 551.22(7) pm, c = 891.99(11) pm, β = 107.09(1)°; Tb (Powder data): a = 1 108.88(20) pm, b = 552.71(9) pm, c = 889.56(16) pm, β = 107.30(1)°; Dy: a = 1 100.28(23) pm, b = 547.77(8) pm, c = 882.41(13) pm, β = 107.32(1); Ho: a = 1 099.11(16) pm, b = 546.16(7) pm, c = 879.45(15) pm, β = 107.34(1)°; Er: a = 1 095.10(16) pm, b = 544.82(10) pm, c = 874.85(14) pm, β = 107.37(1)°.     

Solvothermal Syntheses of (H_2en)_2Sn_2S_6·en and[(H_2hmda)_3(Hhmda)_2](Sn_2S_6)_2Using SnCl_4 and S_8 as Starting Materials

1 INTRODUCTION Since Bedard et al. reported microporous tin(IV) sulfides synthesized by hydrothermal method in the presence of organic amine in 1989[1, 2], a number of thiostannates have been synthesized using hydro- or solvothermal techniques with organic amines as tem- plates. The structures of the resulting tin(IV) sulfi- des are related to the types of organic amines. Two- dimensional polyanions of the types of [Sn3S7]2- and [Sn4S9]2-, which are denoted as SnS-1 and SnS-3, respe…     

Ternary arsenides A2Zn2As3 (A = Sr, Eu) and their stuffed derivatives A2Ag2ZnAs3

The ternary arsenides A(2)Zn(2)As(3) and the quaternary derivatives A(2)Ag(2)ZnAs(3) (A = Sr, Eu) have been prepared by stoichiometric reaction of the elements at 800 °C. Compounds A(2)Zn(2)As(3) crystallize with the monoclinic Ba(2)Cd(2)Sb(3)-type structure (Pearson symbol mC28, space group C2/m, Z = 4; a = 16.212(5) ?, b = 4.275(1) ?, c = 11.955(3) ?, β = 126.271(3)° for Sr(2)Zn(2)As(3); a = 16.032(4) ?, b = 4.255(1) ?, c = 11.871(3) ?, β = 126.525(3)° for Eu(2)Zn(2)As(3)) in which CaAl(2)Si(2)-type fragments, built up of edge-sharing Zn-centered tetrahedra, are interconnected by homoatomic As-As bonds to form anionic slabs [Zn(2)As(3)](4-) separated by A(2+) cations. Compounds A(2)Ag(2)ZnAs(3) crystallize with the monoclinic Yb(2)Zn(3)Ge(3)-type structure (Pearson symbol mC32, space group C2/m; a = 16.759(2) ?, b = 4.4689(5) ?, c = 12.202(1) ?, β = 127.058(1)° for Sr(2)Ag(2)ZnAs(3); a = 16.427(1) ?, b = 4.4721(3) ?, c = 11.9613(7) ?, β = 126.205(1)° for Eu(2)Ag(2)ZnAs(3)), which can be regarded as a stuffed derivative of the Ba(2)Cd(2)Sb(3)-type structure with additional transition-metal atoms in tetrahedral coordination inserted to link the anionic slabs together. The Ag and Zn atoms undergo disorder but with preferential occupancy over four sites centered in either tetrahedral or trigonal planar geometry. The site distribution of these metal atoms depends on a complex interplay of size and electronic factors. All compounds are Zintl phases. Band structure calculations predict that Sr(2)Zn(2)As(3) is a narrow band gap semiconductor and Sr(2)Ag(2)ZnAs(3) is a semimetal. Electrical resistivity measurements revealed band gaps of 0.04 eV for Sr(2)Zn(2)As(3) and 0.02 eV for Eu(2)Zn(2)As(3), the latter undergoing an apparent metal-to-semiconductor transition at 25 K.     

Extreme differences in oxidation states: synthesis and structural analysis of the germanide oxometallates A10[Ge9]2[WO4] as well as A(10+x)[Ge9]2[W(1–x)Nb(x)O4] with A = K and Rb containing [Ge9]4- polyanions

Semitransparent dark-red or ruby-red moisture- and air-sensitive single crystals of A(10+x)[Ge(9)](2)[W(1-x)Nb(x)O(4)] (A = K, Rb; x = 0, 0.35) were obtained by high-temperature solid-state reactions. The crystal structure of the compounds was determined by single-crystal X-ray diffraction experiments. They crystallize in a new structure type (P2(1)/c, Z = 4) with a = 13.908(1) ?, b = 15.909(1) ?, c = 17.383(1) ?, and β = 90.050(6)° for K(10.35(1))[Ge(9)](2)[W(0.65(1))Nb(0.35(1))O(4)]; a = 14.361(3) ?, b = 16.356(3) ?, c = 17.839(4) ?, and β = 90.01(3)° for Rb(10.35(1))[Ge(9)](2)[W(0.65(1))Nb(0.35(1))O(4)]; a = 13.8979(2) ?, b = 15.5390(3) ?, c = 17.4007(3) ?, and β = 90.188(1)° for K(10)[Ge(9)](2)WO(4); and a = 14.3230(7) ?, b = 15.9060(9) ?, c = 17.8634(9) ?, and β = 90.078(4)° for Rb(10)[Ge(9)](2)WO(4). The compounds contain discrete Ge(9)(4-) Wade's nido clusters and WO(4)(2-) (or NbO(4)(3-)) anions, which are packed according to a hierarchical atom-to-cluster replacement of the Al(2)Cu prototype and are separated by K and Rb cations, respectively. The alkali metal atoms occupy the corresponding tetrahedral sites of the Al(2)Cu prototype. The amount of the alkali metal atoms on these diamagnetic compounds corresponds directly to the amount of W substituted by Nb. Thus, the transition metals W and Nb appear with oxidation numbers +6 and +5, respectively, in the vicinity of a [Ge(9)](4-) polyanion. The crystals of the mixed salts were further characterized by Raman spectroscopy. The Raman data are in good agreement with the results from the X-ray structural analyses.     

Structure and physical properties of ternary rare-earth cobalt bismuth intermetallics (RE)12Co5Bi (RE = Y, Gd, Tb, Dy, Ho, Er, Tm)

The rare-earth intermetallic compounds (RE)12Co5Bi (RE = Y, Gd, Tb, Dy, Ho, Er, Tm) were prepared by arc-melting and annealing at 600 degrees C. These compounds extend the previously known (RE)6M2+xX1-x (M = Co, Ni; X = Ga, In, Sn, Pb) series with the Ho6Co2Ga-type structure to X = Bi. The crystal structure of Ho12Co5Bi was refined by the Rietveld method from powder X-ray diffraction data obtained using synchrotron radiation (Pearson symbol oI36, orthorhombic, space group Immm, Z = 2, a = 9.37598(14) A, b = 9.37871(14) A, c = 9.85465(13) A). Unlike other Ho6Co2Ga-type compounds, the 2a site in Ho12Co5Bi is exclusively occupied by Co atoms. Four-probe electrical resistivity measurements on sintered polycrystalline samples of (RE)12Co5Bi indicated metallic behavior. Magnetic measurements revealed behavior ranging from frequency-dependent maxima in the ac susceptibility for Y12Co5Bi to possible ferrimagnetic ordering for Gd12Co5Bi to antiferromagnetic ordering with metamagnetic transitions for the remaining compounds. As confirmed by band structure calculations using Y12Co5Bi as a model compound, Y-Y and Y-Co interactions are the most important bonding components, but matrix effects are likely responsible for anomalously short Co-Co contacts in the structure.     

High-pressure preparation,crystal structure,and properties of alpha-(RE)2B4O9 (RE=Eu,Gd, Tb,Dy): oxoborates displaying a new type of structure with edge-sharing BO4 tetrahedra

High-pressure/high-temperature conditions of 10 GPa and 1150 degrees C were used to synthesize the new rare-earth oxoborates alpha-(RE)(2)B(4)O(9) (RE=Eu, Gd, Tb, Dy) in a Walker-type multianvil apparatus. Single-crystal X-ray structure determination of alpha-(RE)(2)B(4)O(9) (RE=Eu, Gd, Tb) revealed: C2/c, Z=20, alpha-Eu(2)B(4)O(9): a=2547.9(5), b=444.3(1), c=2493.8(5) pm, beta=99.82(3) degrees, R1=0.0277, wR2=0.0693 (all data); alpha-Gd(2)B(4)O(9): a=2539.0(1), b=443.3(1), c=2490.8(1) pm, beta=99.88(1) degrees, R1=0.0457, wR2=0.0643 (all data); alpha-Tb(2)B(4)O(9): a=2529.4(1), b=441.6(1), c=2484.3(1) pm, beta=99.88(1) degrees, R1=0.0474, wR2=0.0543 (all data). The isotypic compounds exhibit a new type of structure that is built up of BO(4) tetrahedra to form a network that incorporates the rare-earth cations. The most important feature is the existence of the new structural motif of edge-sharing BO(4) tetrahedra next to the known motif of corner-sharing BO(4) tetrahedra, which is realized in the presented compounds alpha-(RE)(2)B(4)O(9) (RE=Eu, Gd, Tb, Dy) for the second time. Furthermore, we report the temperature-resolved in-situ powder-diffraction measurements, DTA, IR/Raman spectroscopic investigations, and magnetic properties of the new compounds.     

Indium flux synthesis of RE4Ni2InGe4 (RE = Dy, Ho, Er, and Tm): an ordered quaternary variation on the binary phase Mg5Si6

The quaternary compounds RE4Ni2InGe4 (RE = Dy, Ho, Er, and Tm) were obtained as large single crystals in high yields from reactions run in liquid In. The title compounds crystallize in the monoclinic C2/m space group with the Mg(5)Si(6) structure type with lattice parameters a = 15.420(2) A, b = 4.2224(7) A, c = 7.0191(11) A, and beta = 108.589(2) degrees for Dy4Ni2InGe4, a = 15.373(4) A, b = 4.2101(9) A, c = 6.9935(15) A, and beta = 108.600(3) degrees for Ho4Ni2InGe4, a = 15.334(7) A, b = 4.1937(19) A, c = 6.975(3) A, and beta =108.472(7) degrees for Er4Ni2InGe4, and a = 15.253(2) A, b = 4.1747(6) A, c = 6.9460(9) A, and beta = 108.535(2) degrees for Tm4Ni2InGe4. RE4Ni2InGe4 formed in liquid In from a melt that was rich in the rare-earth component. These compounds are polar intermetallic phases with a cationic rare-earth substructure embedded in a transition metal and main group matrix. The rare-earth atoms form a highly condensed network, leading to interatomic distances that are similar to those found in the elemental lanthanides themselves. The Dy and Ho analogues display two maxima in the susceptibility, suggesting antiferromagnetic ordering behavior and an accompanying spin reorientation. The Er analogue shows only one maximum in the susceptibility, and no magnetic ordering was observed for the Tm compound down to 2 K.     

General synthesis and structural evolution of a layered family of Ln8(OH)20Cl4 x nH2O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y)

The synthesis process and crystal structure evolution for a family of stoichiometric layered rare-earth hydroxides with general formula Ln(8)(OH)(20)Cl(4) x nH(2)O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y; n approximately 6-7) are described. Synthesis was accomplished through homogeneous precipitation of LnCl(3) x xH(2)O with hexamethylenetetramine to yield a single-phase product for Sm-Er and Y. Some minor coexisting phases were observed for Nd(3+) and Tm(3+), indicating a size limit for this layered series. Light lanthanides (Nd, Sm, Eu) crystallized into rectangular platelets, whereas platelets of heavy lanthanides from Gd tended to be of quasi-hexagonal morphology. Rietveld profile analysis revealed that all phases were isostructural in an orthorhombic layered structure featuring a positively charged layer, [Ln(8)(OH)(20)(H(2)O)(n)](4+), and interlayer charge-balancing Cl(-) ions. In-plane lattice parameters a and b decreased nearly linearly with a decrease in the rare-earth cation size. The interlamellar distance, c, was almost constant (approximately 8.70 A) for rare-earth elements Nd(3+), Sm(3+), and Eu(3+), but it suddenly decreased to approximately 8.45 A for Tb(3+), Dy(3+), Ho(3+), and Er(3+), which can be ascribed to two different degrees of hydration. Nd(3+) typically adopted a phase with high hydration, whereas a low-hydration phase was preferred for Tb(3+), Dy(3+), Ho(3+), Er(3+), and Tm(3+). Sm(3+), Eu(3+), and Gd(3+) samples were sensitive to humidity conditions because high- and low-hydration phases were interconvertible at a critical humidity of 10%, 20%, and 50%, respectively, as supported by both X-ray diffraction and gravimetry as a function of the relative humidity. In the phase conversion process, interlayer expansion or contraction of approximately 0.2 A also occurred as a possible consequence of absorption/desorption of H(2)O molecules. The hydration difference was also evidenced by refinement results. The number of coordinated water molecules per formula weight, n, changed from 6.6 for the high-hydration Gd sample to 6.0 for the low-hydration Gd sample. Also, the hydration number usually decreased with increasing atomic number; e.g., n = 7.4, 6.3, 7.2, and 6.6 for high-hydration Nd, Sm, Eu, and Gd, and n = 6.0, 5.8, 5.6, 5.4, and 4.9 for low-hydration Gd, Tb, Dy, Ho, and Er. The variation in the average Ln-O bond length with decreasing size of the lanthanide ions is also discussed. This family of layered lanthanide compounds highlights a novel chemistry of interplay between crystal structure stability and coordination geometry with water molecules.     

Synthesis, Characterization, and Bonding of Two New Heteropolychalcogenides: alpha-CsCu(S(x)()Se(4-x)) and CsCu(S(x)()Se(6-x))

The Cs-Cu-Q (Q = S, Se) system has been investigated using copper metal, cesium chloride, and alkali-metal polychalcogenide salts under mild hydrothermal reaction conditions. Heteropolychalcogenide salts and mixtures of known polysulfide and polyselenide salts have been used as reagents. The reaction products contain the alpha-CsCuQ(4) and CsCuQ(6) structures. The alpha-CsCuQ(4) phase exhibits a smooth transition in lattice parameters from the pure sulfur to the pure selenium phases, based on Vegard's law. The CsCuQ(6) phase has been prepared as the pure sulfur analog and a selenium rich analog. The single-crystal structures of the disordered compounds alpha-CsCuS(2)Se(2) (P2(1)2(1)2(1), Z = 4, a = 5.439(1) ?, b = 8.878(2) ?, c = 13.762(4) ?) and CsCuS(1.6)Se(4.4) (P&onemacr;, Z = 2, a = 11.253(4) ?, b = 11.585(2) ?, c = 7.211(2) ?, alpha = 92.93 degrees, beta = 100.94 degrees, gamma = 74.51 degrees ) have been solved using a correlated-site occupancy model. These disordered structures display a polychalcogenide geometry in which the sulfur atoms prefer positions that are bound to copper. The optical absorption spectra of these materials have been investigated. The optical band gap varies as a function of the sulfur-selenium ratio. Extended Hückel crystal orbital calculations have been performed to investigate the electronic structure and bonding in these compounds in an attempt to explain the site distribution of sulfur and selenium.     

Investigation of the crystal structure of a basic bismuth(III) nitrate with the composition [Bi6O4(OH)4](0.54(1))[Bi6O5(OH)3](0.46(1))(NO3)(5.54(1))

A basic bismuth(III) nitrate with the composition [Bi(6)O(4)(OH)(4)](0.5)[Bi(6)O(5)(OH)(3)](0.5)(NO(3))(5.5) formed in a slow crystal growth mode has an ordered crystal structure with the monoclinic space group P2(1) and lattice parameters a = 15.850(3), b = 14.986(3), c = 18.230(4) ?, β = 107.329(17)° and volume V = 4133.6 ?(3) (Henry et al. 2003). In a very fast crystal growth mode the complex ions disorder in another P2(1) cell with slightly different lattice parameters a = 15.8404(1), b = 15.1982(1), c = 18.3122(1) ?, β = 106.829(1)° and V = 4219.8 ?(3). This cell can be related to two smaller cells: a monoclinic C2/m cell with a = 13.7161(1), b = 15.1943(1), c = 10.2399(1) ?, β = 98.586(1)° and V = 2110.1 ?(3) and a trigonal R3 cell with a = 15.18650(6), c = 15.8416(1) ? (hexagonal setting) and V = 3164.1 ?(3). These smaller cells correspond to average structures and hence the X-ray data do not account for the difference in the structures of the two different complex ions. However, when analysing neutron powder diffraction data, it is possible to distinguish between the two complex ions using a trigonal R3 cell with a = 15.1865(1) and c = 15.8416(1) ? (hexagonal setting). In a Rietveld type structure model refinement with a total of 28 atom sites (4 Bi, 3 N, 15 O and 6 H), the composition of this sample is determined to be [Bi(6)O(4)(OH)(4)](0.54(1))[Bi(6)O(5)(OH)(3)](0.46(1))(NO(3))(5.54(1)).     

Ternary rare-earth arsenides REZn3As3 (RE = La-Nd, Sm) and RECd3As3 (RE = La-Pr)

Ternary rare-earth zinc arsenides REZn(3)As(3) (RE = La-Nd, Sm) with polymorphic modifications different from the previously known defect CaAl(2)Si(2)-type forms, and the corresponding rare-earth cadmium arsenides RECd(3)As(3) (RE = La-Pr), have been prepared by reaction of the elements at 800 °C. LaZn(3)As(3) adopts a new orthorhombic structure type (Pearson symbol oP28, space group Pnma, Z = 4, a = 12.5935(8) ?, b = 4.1054(3) ?, c = 11.5968(7) ?) in which ZnAs(4) tetrahedra share edges to form ribbons that are fragments of other layered arsenide structures; these ribbons are then interconnected in a three-dimensional framework with large channels aligned parallel to the b direction that are occupied by La(3+) cations. All remaining compounds adopt the hexagonal ScAl(3)C(3)-type structure (Pearson symbol hP14, space group P6(3)/mmc, Z = 2; a = 4.1772(7)-4.1501(2) ?, c = 20.477(3)-20.357(1) ? for REZn(3)As(3) (RE = Ce, Pr, Nd, Sm); a = 4.4190(3)-4.3923(2) ?, c = 21.4407(13)-21.3004(8) ? for RECd(3)As(3) (RE = La-Pr)) in which [M(3)As(3)](3-) layers (M = Zn, Cd), formed by a triple stacking of nets of close-packed As atoms with M atoms occupying tetrahedral and trigonal planar sites, are separated by La(3+) cations. Electrical resistivity measurements and band structure calculations revealed that orthorhombic LaZn(3)As(3) is a narrow band gap semiconductor.     

Diverse closed cavities in condensed rare earth metal-chalcogenide matrixes: Cs[Lu7Q11] and (ClCs6)[RE21Q34] (RE = Dy, Ho; Q = S, Se, Te)

Two types of novel ordered chalcogenids Cs[Lu(7)Q(11)] (Q = S, Se) and (ClCs(6))[RE(21)Q(34)] (RE = Dy, Ho; Q = S, Se, Te) were discovered by high-temperature solid state reactions. The structures were characterized by single-crystal X-ray diffraction data. Cs[Lu(7)Q(11)] crystallize in the orthorhombic Cmca (no. 64) with a = 15.228(4)-15.849(7) ?, b = 13.357(3)-13.858(6) ?, c = 18.777(5)-19.509(8) ?, and Z = 8. (ClCs(6))[RE(21)Q(34)] crystallize in the monoclinic C2/m (no. 12) with a = 17.127(2)-18.868(2) ?, b = 19.489(2)-21.578(9) ?, c = 12.988(9)-14.356(2) ?, β = 128.604(2)-128.738(4)°, and Z = 2. Both types of compounds feature 3D RE-Q network structures that embed with dual tricapped cubes Cs(2)@Se(18) in the former or unprecedented matryoshka nesting doll structure cavities of (ClCs(6))@Se(32) in the latter. The band gap, band structure, as well as a structure change trend of the majority of A/RE/Q compounds are presented.     

Crystal Structures and Magnetic Properties of Novel [Ln(III)Cu(II)(4)] (Ln = Gd, Dy, Ho) Pentanuclear Complexes. Topology and Ferromagnetic Interaction in the Ln(III)-Cu(II) Pair

The first pentanuclear complexes of formula {Dy[Cu(apox)](2)[Cu(apox)(H(2)O)](2)}[ClO(4)](3).7H(2)O (1), {Ho[Cu(apox)][Cu(apox)(H(2)O)](3)}[PF(6)](3).4.5H(2)O (2), {Gd[Cu(apox)](2)[Cu(apox)(H(2)O)](2)}[ClO(4)](3).7H(2)O (3) and {Gd[Cu(apox)][Cu(apox) (H(2)O)](3)}[PF(6)](3).4.5H(2)O (4) (H(2)apox = N,N'-bis(3-aminopropyl)oxamide) have been synthesized. The crystal structures of complexes 1 and 2 have been determined by X-ray diffraction methods. Complexes 3 and 4 are isostructural with 1 and 2, respectively. Crystallographic data are as follows: 1 and 3, monoclinic, space group C2/c and Z = 4, with a = 14.646(6) ?, b = 29.496(7) ?, c = 16.002(7) ?, and beta = 111.76(2) degrees for 1 and a = 14.523(6) ?, b = 29.441(6) ?, c = 15.925(8) ?, and beta = 111.90(4) degrees for 3; 2 and 4, triclinic, P&onemacr;, and Z = 2, with a = 14.346(2) ?, b = 14.454(2) ?, c = 18.107(4) ?, alpha = 90.95(2) degrees, beta = 110.75(2) degrees, and gamma = 106.77(2) degrees for 2 and a = 14.365(6) ?, b = 14.496(5) ?, c = 18.172(7) ?, alpha = 91.27(3) degrees, beta = 110.74(3) degrees, and gamma = 106.67(3) degrees for 4. A tripositive ion is present in these structures, the electroneutrality being achieved by three uncoordinated perchlorate (1) or hexafluorophosphate (2) anions. The lanthanide cations are eight-coordinate with a pseudo-square-antiprismatic environment formed by carbonyl oxygen atoms from two [Cu(apox)] and two Cu(apox)(H(2)O)] (1) and one [Cu(apox)] and three [Cu(apox)(H(2)O)] (2) bidentate ligands. The temperature dependence of the magnetic susceptibility of complexes 1-4 was investigated in the range 1.8-300 K. The ligand-field effect, as well as the mixing of the free-ion states in Dy(III) and Ho(III), make extremely difficult the analysis of the overall antiferromagnetic interaction which is observed for complexes 1 and 2. The magnetic susceptibility data for complexes 3 and 4 have shown that the ground-state spin for the [Gd(III)Cu(II)(4)] unit is S = 11/2, the Gd(III)-Cu(II) interaction being ferromagnetic with an interaction parameter J(GdCu) = 0.85 cm(-)(1) (the interaction Hamiltonian is of the form H = -JS(A).S(B)). The field dependence of the magnetization at 2 K of 3 and 4 confirms the nature of the ground state and of the Gd(III)-Cu(II) interaction. The influence of the topology and of the type of bridging ligand on the nature and magnitude of the magnetic interaction in the Gd(III)-Cu(II) pair is analyzed and discussed in light of available magnetostructural data.     

Aluminosilicate relatives: Chalcogenoaluminogermanates Rb(3)(AlQ(2))(3)(GeQ(2))(7) (Q = S, Se)

The new compounds Rb(3)(AlQ(2))(3)(GeQ(2))(7) [Q = S (1), Se (2)] feature the 3D anionic open framework [(AlQ(2))(3)(GeQ(2))(7)](3-) in which aluminum and germanium share tetrahedral coordination sites. Rb ions are located in channels formed by the connection of 8, 10, and 16 (Ge/Al)S(4) tetrahedra. The isostructural sulfur and selenium derivatives crystallize in the space group P2(1)/c. 1: a = 6.7537(3) ?, b = 37.7825(19) ?, c = 6.7515(3) ?, and β = 90.655(4)°. 2: a = 7.0580(5) ?, b = 39.419(2) ?, c = 7.0412(4) ?, β = 90.360(5)°, and Z = 2 at 190(2) K. The band gaps of the congruently melting chalcogenogermanates are 3.1 eV (1) and 2.4 eV (2).     

New Zr(6)MTe(2) (M = Mn, Fe, Co, Ni, Ru, Pt), Zr(6)Fe(0.6)Se(2.4), and Zr(6)Fe(0.57)S(2.43) Intermetallics: Structural Links between Binary (Zr,Hf)(3)M Alloys and Porous Metal-Rich Tellurides

The synthesis of the group IV ternary chalcogenides Zr(6)MTe(2) (M = Mn, Fe, Co, Ni, Ru, Pt) and Zr(6)Fe(1)(-)(x)()Q(2+)(x)() (Q = S, Se) is reported, as are the single-crystal structures of Zr(6)FeTe(2), Zr(6)Fe(0.6)Se(2.4), and Zr(6)Fe(0.57)S(2.43). The structure of Zr(6)FeTe(2) was refined in the hexagonal space group P&sixmacr;2m (No. 189, Z = 1) with lattice parameters a = 7.7515(5) ? and c = 3.6262(6) ?, and the structures of Zr(6)Fe(0.6)Se(2.4) and Zr(6)Fe(0.57)S(2.43) were refined in the orthorhombic space group Pnnm (No. 58, Z = 4) with lattice parameters a = 12.737(2) ?, b = 15.780(2) ?, and c = 3.5809(6) ? and a = 12.519(4) ?, b = 15.436(2) ?, and c = 3.4966(6) ?, respectively. The cell parameters of Mn-, Co-, Ni-, Ru-, and Pt-containing tellurides were also determined. The Zr(6)ZTe(2) compounds are isostructural with Zr(6)CoAl(2), while Zr(6)Fe(1)(-)(x)()Q(2+)(x)() (Q = S, Se) were found to adopt a variant of the Ta(2)P-type structure. Chains of condensed M-centered, tetrakaidecahedra of zirconium constitute the basic structural unit in all these compounds. The modes of cross-linking that give rise to the Zr(6)FeTe(2) and Zr(6)Fe(1)(-)(x)()Q(2+)(x)() structures, differences among the title compounds, and the influence of chalcogen size differences are discussed. The stoichiometric nature of Zr(6)FeTe(2) and its contrast with sulfur and selenium congeners apparently result from a Te-Fe size mismatch. The importance of stabilization of both Zr(6)FeSe(2) and Zr(6)FeTe(2) compounds by polar intermetallic Zr-Fe bonding is underscored by a bonding analysis derived from electronic band structure calculations.     

Thiophosphate phase diagrams developed in conjunction with the synthesis of the new compounds KLaP(2)S(6), K(2)La(P(2)S(6))(1/2)(PS(4)), K(3)La(PS(4))(2), K(4)La(0.67)(PS(4))(2), K(9-)(x)La(1+x/3)(Ps(4))(4) (x = 0.5), K(4)Eu(PS(4))(2), and KEuPS(4)

An alkali-metal sulfur reactive flux has been used to synthesize a series of quaternary rare-earth metal compounds. These include KLaP(2)S(6) (I), K(2)La(P(2)S(6))(1/2)(PS(4)) (II), K(3)La(PS(4))(2) (III), K(4)La(0.67)(PS(4))(2) (IV), K(9-x)La(1+x/3)(PS(4))(4) (x = 0.5) (V), K(4)Eu(PS(4))(2) (VI), and KEuPS(4) (VII). Compound I crystallizes in the monoclinic space group P2(1)/c with the cell parameters a = 11.963(12) A, b = 7.525(10) A, c = 11.389(14) A, beta = 109.88(4) degrees, and Z = 4. Compound II crystallizes in the monoclinic space group P2(1)/n with a = 9.066(6) A, b = 6.793(3) A, c = 20.112(7) A, beta = 97.54(3) degrees, and Z = 4. Compound III crystallizes in the monoclinic space group P2(1)/c with a= 9.141(2) A, b = 17.056(4) A, c = 9.470(2) A, beta = 90.29(2) degrees, and Z = 4. Compound IV crystallizes in the orthorhombic space group Ibam with a = 18.202(2) A, b = 8.7596(7) A, c = 9.7699(8) A, and Z = 4. Compound V crystallizes in the orthorhombic space group Ccca with a = 17.529(9) A, b = 36.43(3) A, c = 9.782(4) A, and Z = 8. Compound VI crystallizes in the orthorhombic space group Ibam with a = 18.29(5) A, b = 8.81(2) A, c= 9.741(10) A, and Z = 4. Compound VII crystallizes in the orthorhombic space group Pnma with a = 16.782(2) A, b = 6.6141(6) A, c = 6.5142(6) A, and Z = 4. The sulfur compounds are in most cases isostructural to their selenium counterparts. By controlling experimental conditions, these structures can be placed in quasi-quaternary phase diagrams, which show the reaction conditions necessary to obtain a particular thiophosphate anionic unit in the crystalline product. These structures have been characterized by Raman and IR spectroscopy and UV-vis diffuse reflectance optical band gap analysis.     

镧系金属高氯酸盐与1.8-萘啶氮氧化物配合物的合成、性质和结构

本文合成了镧系金属高氯酸盐与1,8-萘啶氮氧化物形成的Ln(C8H6N2O)4(ClO4)3(Ln=Sm-Lu)的固体配合物. 进行了元素分析、红外光谱、差热-热重分析和摩尔电导测定, 并作了Eu(ClO4)2与1,8-萘啶氮氧化物配合物的X射线单晶结构分析. 结果表明Eu^3^+离子与4个配体的氧原子和氮原子配位, 配位数为8.