On the system cerium-platinum-silicon

Phase relations in the ternary system Ce-Pt-Si have been established for the isothermal section at 800 °C based on X-ray powder diffraction, metallography, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) techniques on about 120 alloys, which were prepared by various methods employing arc-melting under argon or powder reaction sintering. Nineteen ternary compounds were observed. Atom order in the crystal structures of τ₁₈-Ce₅(Pt,Si)₄ (Pnma; a=0.77223(3) nm, b=1.53279(8) nm c=0.80054(5) nm), τ₃-Ce₂Pt₇Si₄ (Pnma; a=1.96335(8) nm, b=0.40361(4) nm, c=1.12240(6) nm) and τ₁₀-CePtSi₂ (Cmcm; a=0.42943(2) nm, b=1.67357(5) nm, c=0.42372(2) nm) was determined by direct methods from X-ray single-crystal CCD data and found to be isotypic with the Sm₅Ge₄-type, the Ce₂Pt₇Ge₄-type and the CeNiSi₂-type, respectively. Rietveld refinements established the atom arrangement in the structures of Pt₃Si (Pt₃Ge-type, C2/m, a=0.7724(2) nm, b=0.7767(2) nm, c=0.5390(2) nm, β=133.86(2)°), τ₁₆-Ce₃Pt₅Si (Ce₃Pd₅Si-type, Imma, a=0.74025(8) nm, b=1.2951(2) nm, c=0.7508(1) nm) and τ₁₇-Ce₃PtSi₃ (Ba₃Al₂Ge₂-type, Immm, a=0.41065(5) nm, b=0.43221(5) nm, c=1.8375(3) nm). Phase equilibria in Ce-Pt-Si are characterised by the absence of cerium solubility in platinum silicides. Cerium silicides and cerium platinides, however, dissolve significant amounts of the third component, whereby random substitution of the almost equally sized atom species platinum and silicon is reflected in extended homogeneous regions at constant Ce content such as for τ₁₃-Ce(Pt_xSi_1−x)₂, τ₆-Ce₂Pt_3+xSi_5−x or τ₇-CePt_2−xSi_2+x.     

Synthesis and structural characterization of A3In2Ge4 and A5In3Ge6 (A=Ca, Sr, Eu, Yb)—New intermetallic compounds with complex structures, exhibiting Ge-Ge and In-In bonding

Reported are the synthesis and the structural characterization of four new polar intermetallic phases, which exist only with mixed alkaline-earth and rare-earth metal cations in narrow homogeneity ranges. (Sr_1-xCa_x)₅In₃Ge₆ and (Eu_1-xYb_x)₅In₃Ge₆ (x≈0.7) crystallize in the orthorhombic space group Pnma with two formula units per unit cell (own structure type, Pearson symbol oP56). The lattice parameters are as follows: a=13.109(3)-13.266(3) Å, b=4.4089(9)-4.4703(12) Å, and c=23.316(5)-23.557(6) Å. (Sr_1-xCa_x)₃In₂Ge₄ and (Sr_1-xYb_x)₃In₂Ge₄ (x≈0.4-0.5) adopt another novel monoclinic structure-type (space group C2/m, Z=4, Pearson symbol mS36) with lattice parameters in the range a=19.978(2)-20.202(2) Å, b=4.5287(5)-4.5664(5) Å, c=10.3295(12)-10.3447(10) Å, and β=98.214(2)-98.470(2)°, depending on the metal cations and their ratio. The polyanionic sub-structures in both cases are based on chains of InGe₄ corner-shared tetrahedra. The A₅In₃Ge₆ structure (A=Sr/Ca or Sr/Yb) also features Ge₄ tetramers, and isolated In atoms in nearly square-planar environment, while the A₃In₂Ge₄ structure (A=Sr/Ca or Eu/Yb) contains zig-zag chains of In and Ge strings with intricate topology of cis- and trans-bonds. The experimental results have been complemented by tight-binding linear muffin-tin orbital (LMTO) band structure calculations.     

Reaction of chlorine with platinum(IV) triamine containing N,N-dimethylethylenediamine. The crystal structure of [Pt{(CH3)2N(CH2)2NH2}PyCl3]Cl·H2O[Pt{(CH3)2N(CH2)2NCl}PyCl3], and [Pt{(CH3)2N(CH2)2NH2}PyCl4]

The Platinum(II) diamine with N,N-dimethylethylenediamine (N,N-dimeEn) [Pt{(CH₃)₂N(CH₂)₂NH₂}Cl₂] (I) was synthesized. The reaction of the diamine with pyridine gave Pt(II) tetramine [Pt{(CH₃)₂N(CH₂)₂NH₂}Py₂]Cl₂ (II), which was oxidized with chlorine to give Pt(IV) triamine Pt{[(CH₃)₂N(CH₂)₂}PyCl₃]Cl · H₂O (III). The reaction of III with chlorine (chloroamidation) yielded chloroimide [Pt{(CH₃)₂N(CH₂)₂NCl}PyCl₃] (IV). The IR spectra of complexes I–IV and UV/Vis spectra of III and IV were studied. X-Ray diffraction analysis was performed for III (monoclinic crystals, space group P2₁/c, a = 7.7437(6), b = 8.1100(7), c = 28.52992(2) Å, β = 93.7280(10)°, Z = 4, R _hkl = 0.0420) and IV (orthorhombic crystals, space group Pna2₁, a = 15.7825(12), b = 7.4447(6), c = 12.3099(6) Å, Z = 4, R _hkl = 0.0539). During oxidation of Pt(II) tetramine with chlorine, the pyridine molecule is removed from the cis position relative to the (CH₃)₂N group (trans position relative to the NH₂ group) of N,N-dimethylethylenediamine. The reaction of chloroimide complex IV with concentrated HCl (dechloroamidation) at 20°C afforded the initial complex III; that at 100°C, gave triamine III together with Pt(IV) diamine [Pt(N,N-dimeEn)Cl₄] (V) (monoclinic crystals, space group P2₁/n, a = 7.1278(5), b = 11.5384(8), c = 12.7501(9) Å, β = 93.23(10)°, Z = 4, R _hkl = 0.0239).     

New Gallium Phosphate Frameworks Containing 1,4-Diaminobutane and 1,5-Diaminopentane: [NH3(CH2)xNH3][Ga4(PO4)4(HPO4)] and [NH3(CH2)xNH3][Ga(PO4)(HPO4)] (x=4 and 5)

Two new gallium phosphates, [NH₃(CH₂)₄NH₃][Ga₄(PO₄)₄ (HPO₄)] (I) and [NH₃(CH₂)₄NH₃][Ga(PO₄)(HPO₄)] (II), have been synthesized under solvothermal conditions in the presence of 1,4-diaminobutane and their structures determined using room-temperature single-crystal X-ray diffraction data. Compound (I) (M_r=844.90, triclinic, space group P-1, a=9.3619(3), b=10.1158(3) and c=12.6456(5) Å, α=98.485(1), β=107.018(2) and γ=105.424(1)°; V=1070.39 ų, Z=2, R=3.68% and R_w=4.40% for 2918 observed data [I>3(σ(I))]) consists of GaO₄ and PO₄ tetrahedra and GaO₅ trigonal bipyramids linked to generate an open three-dimensional framework containing 4-, 6-, 8-, and 12-membered rings of alternating Ga- and P-based polyhedra. 1,4-Diaminobutane dications are located in channels bounded by the 12-membered rings in the two-dimensional pore network and are held to the framework by hydrogen bonding. Compound (II) (M_r=350.84, monoclinic, space group P2₁/c, a=4.8922(1), b=18.3638(6) and c=13.7468(5) Å, β=94.581(1)°; V=1227.76 ų, Z=4, R=2.95% and R_w=3.37% for 2050 observed data [I>3(σ(I))]) contains chains of edge-sharing 4-membered rings of alternating GaO₄ and PO₄ tetrahedra constituting a backbone from which hang ‘pendant’ PO₃(OH) groups. Hydrogen bonding between the GaPO framework and the diamine dications holds the structure together. A previously reported phase, [NH₃(CH₂)₄NH₃][Ga₄(PO₄)₄(HPO₄)] (V), structurally related but distinct from its stoichiometric equivalent, (I), has been prepared as a pure phase by this method. Two further materials, [NH₃(CH₂)₅NH₃][Ga₄(PO₄)₄(HPO₄)] (III) (tricli- nic, lattice parameters from PXD: a=9.3565(4), b=5.0156(2) and c=12.7065(4) Å, α=96.612(3), β=102.747(4) and γ=105.277(3)°) and [NH₃(CH₂)₅NH₃][Ga(PO₄)(HPO₄)] (IV) (M_r=364.86, monoclinic, space group P2₁/n, a=4.9239(2), b=13.2843(4) and c=19.5339(7) Å, β=96.858(1)°; V=1268.58 ų, Z=4, R=3.74% and R_w=4.44% for 2224 observed room-temperature data [I>3(σ(I))]), were also prepared under similar conditions in the presence of 1,5-diaminopentane. (III) and (IV) are structurally related to, yet distinct from (I) and (II) respectively.     

Chemical behavior of ortho-hydroquinone-based bis(pyrazol-1-yl)methane ligands in the presence of palladium(II) chloride

The synthesis, structural characterization, and coordination behavior of ditopic ortho-hydroquinone-based bis(pyrazol-1-yl)methane ligands (ortho-(OH)₂C₆H₃-4-CHpz₂, ortho-(OH)₂C₆H₃-4-CH(3-Phpz)₂, and ortho-(OH)₂C₆H₃-4-CH(3-tBupz)₂) with pyrazole, 3-phenylpyrazole, and 3-tert-butylpyrazole as donors are described. The reaction of a soluble PdCl₂-source with ortho-(OH)₂C₆H₃-4-CHpz₂ in acetonitrile yielded the related square-planar N,N-coordinated Pd(II) dichloride complex, whereas treatment of ortho-(OH)₂C₆H₃-4-CH(3-Phpz)₂ or ortho-(OH)₂C₆H₃-4-CH(3-tBupz)₂ with PdCl₂ in acetonitrile resulted in degradation of these ligands. The Pd(II) complexes trans-(3-PhpzH)₂PdCl₂ and trans-(3-tBupzH)₂PdCl₂ were isolated and fully characterized including X-ray diffraction analyses.     

Ligand substitution of FeRu2(CO)12 and Fe2Ru(CO)12 with tertiary phosphines and phosphites

Ligand substitution of the mixed-metal clusters FeRu₂(CO)₁₂ and Fe₂Ru(CO)₁₂ with triphenylphosphine and trimethylphosphite has been studied. Mono- and di-substituted derivatives have been synthesized and characterized structurally. The following crystal and molecular structures are reported: Fe₂Ru(CO)₁₁PPh₃: triclinic, space group P$\text{1}$, a 9.203(2), b 11.903(3), c 15.117(4) Å, α 81.54(2), β 87.28(2), γ 66.72(2)°, Z = 2; Fe₂Ru(CO)₁₁P(OMe)₃: orthorhombic, space group Pna2₁, a 17.220(5), b 14.572(4), c 8.708(6) Å, Z = 4, FeRu₂(CO)₁₁PPh₃: monoclinic, space group P2₁/n, a 11.435(3), b 16.034(5), c 16.642(4) Å, β 93.35(2)°, Z = 4; FeRu₂(CO)₁₀(PPh₃)₂: orthorhombic, space group Pccm, a 14.854(4), b 17.180(7), c 16.786(12) Å, Z = 4.Ligand substitution is found to occur preferentially at the ruthenium centers of the FeRu₂ and Fe₂Ru clusters. Monosubstitution causes expansion of both of the clusters while the overall geometry is practically unchanged. Disubstitution of FeRu₂(CO)₁₂ causes contraction of the cluster and leads to a formation of carbonyl bridges. The structural trends have been interpreted in terms of electronic and packing effects of ligand substitution. The X-ray structures of Fe₂Ru(CO)₁₂ and FeRu₂(CO)₁₂ are not known; the ligand substitution studies indicate that Fe₂Ru(CO)₁₂ has the same structure as Fe₃(CO)₁₂, and that FeRu₃(CO)₁₂ does not have a Ru₃(CO)₁₂ structure as postulated previously from the IR studies.     

Synthesis and structural investigation of the compounds containing HF2 anions: Ca(HF2)2, Ba4F4(HF2)(PF6)3 and Pb2F2(HF2)(PF6)

Three new compounds Ca(HF₂)₂, Ba₄F₄(HF₂)(PF₆)₃ and Pb₂F₂(HF₂)(PF₆) were obtained in the system metal(II) fluoride and anhydrous HF (aHF) acidified with excessive PF₅. The obtained polymeric solids are slightly soluble in aHF and they crystallize out of their aHF solutions. Ca(HF₂)₂ was prepared by simply dissolving CaF₂ in a neutral aHF. It represents the second known compound with homoleptic HF environment of the central atom besides Ba(H₃F₄)₂. The compounds Ba₄F₄(HF₂)(PF₆)₃ and Pb₂F₂(HF₂)(PF₆) represent two additional examples of the formation of a polymeric zigzag ladder or ribbon composed of metal cation and fluoride anion (MF⁺)_n besides PbF(AsF₆), the first isolated compound with such zigzag ladder. The obtained new compounds were characterized by X-ray single crystal diffraction method and partly by Raman spectroscopy. Ba₄F₄(HF₂)(PF₆)₃ crystallizes in a triclinic space group P1¯ with a=4.5870(2) Å, b=8.8327(3) Å, c=11.2489(3) Å, α=67.758(9)°, β=84.722(12), γ=78.283(12)°, V=413.00(3) Å³ at 200 K, Z=1 and R=0.0588. Pb₂F₂(HF₂)(PF₆) at 200 K: space group P1¯, a=4.5722(19) Å, b=4.763(2) Å, c=8.818(4) Å, α=86.967(10)°, β=76.774(10)°, γ=83.230(12)°, V=185.55(14) ų, Z=1 and R=0.0937. Pb₂F₂(HF₂)(PF₆) at 293 K: space group P1¯, a=4.586(2) Å, b=4.781(3) Å, c=8.831(5) Å, α=87.106(13)°, β=76.830(13)°, γ=83.531(11)°, V=187.27(18) Å³, Z=1 and R=0.072. Ca(HF₂)₂ crystallizes in an orthorhombic Fddd space group with a=5.5709(6) Å, b=10.1111(9) Å, c=10.5945(10) Å, V=596.77(10) Å³ at 200 K, Z=8 and R=0.028.     

Studies of the oxovanadium-organophosphonate system: Formation of pyrodiphosphonate and pyrophosphophosphonate units through metal-mediated ligand condensations. The crystal and molecular structures of (Ph4P)2[VO{RP(O)2OP(O)2 R}2] (R=Me,Ph) and (Ph4P)2(n-Bu4N)[(VO)6V{t-BuP(O)2OPO3}6]

Under solvothermal conditions and in the presence of oxovanadium species. organophosphonates undergo self-condensation reactions or condensation with phosphate to yield pyrodiphosphonate {RP(O)₂OP(O)₂ R}², or organophos-phonatophosphate units {RP(O)₂OPO₃}^3-. In this fashion, the reactions of (Ph₄P)[VO₂Cl₂] withRPO₃H₂ (R=CH₃,Ph) and Et₃N in CH₃CN at 110°C yielded (Ph₄P)₂ [VO{RP(O)₂P(O)₂ R}₂](R = CH₃(1), Ph (2)). However, the reaction of {Ph₄P}[VO₂Cl₂],t-BuPO₃H₂ and (n-Bu₄N)H₂PO₄ in acetonitrile at 125°C produced an unusual mixed valence V(IV)/V(III) cluster (Ph₄P)₂ (n-Bu₄N)[(VO)₆V{Me₃CP(O)₂OPO₃}₆] ?3CH₃CN (3). Compounds1 and2 exhibit mononuclear molecular anions with the V(IV) center in the common square pyramidal coordination mode. The organodiphosphonate ligands adopt a bidentate coordination mode. The molecular anion of3 consists of a shell constructed of six V(IV) square pyramids linked by pentadentate {Me₃CP(O)₂OPO₃}^3- groups. Each organophosphonatophosphate ligand bridges four {VO₅}square pyramids of the shell and directs the fifth oxygen donor toward the interior of the cluster, so as to bond to an octahedral V(III) located at the center of the cluster cavity. Crystal data:1, C₂₆H₂₆O_5.5P₃V_0.5: triciinic Pl,a=10.836(2)A,b=ll.418(2)A,c=11.486(2)A,α=82.58(2)°,ß=75.29(2)°,γ=75.61(2)°,V=1328.1(7)A³,Z=2, D_calc=l.362gcm^-3;2, C₃₆H₃₂O_6.5P₃V_0.5: monoclinic P2₁/c,a=12.823(3)A,b=14.318(3)A,c=18.581(4)A,ß=94.76(3)°,V=3999.7(13)A³,Z=4, D_calc=l.342gcm^-3 3, C₉₄H₁₃₉N₄O₄₂P₁₄V₇, triclinic Pl,a=13.589(3)A,b=17.835(4)A,c=38.915(8)A,α=81.64(2)°,ß=81.58(2)°,γ=82.87(2)°,V=9180(3)A³,Z=3, D_calc=l.512gcm^-3.     

On the crystal chemistry of Tm2Ni1.896(4)In, Tm2.22(2)Ni1.81(1)In0.78(2), Tm4.83(3)Ni2In1.17(3), and Er5Ni2In

The rare earth-nickel-indides Tm₂Ni_1.896(4)In, Tm_2.22(2)Ni_1.81(1)In_0.78(2), Tm_4.83(3)Ni₂In_1.17(3), and Er₅Ni₂In were synthesized from the elements by arc-melting and subsequent annealing for the latter three compounds. Three indides were investigated by X-ray powder and single crystal diffraction: Mo₂FeB₂ type, P4/mbm, Z=2, a=731.08(4), c=358.80(3) pm, wR₂=0.0201, 178 F² values, 13 variables for Tm₂Ni_1.896(4)In, a=734.37(7), c=358.6(1) pm, wR₂=0.0539, 262 F² values, 14 variables for Tm_2.22(2)Ni_1.81(1)In_0.78(2), and Mo₅SiB₂ type, I4/mcm, a=751.0(2), c=1317.1(3) pm, wR₂=0.0751, 317 F² values, 17 variables for Tm_4.83(3)Ni₂In_1.17(3). X-ray powder data for Er₅Ni₂In revealed a=754.6(2) and c=1323.3(5) pm. The Mo₂FeB₂ type structures of Tm₂Ni_1.896(4)In and Tm_2.22(2)Ni_1.81(1)In_0.78(2) are intergrowths of slightly distorted CsCl and AlB₂ related slabs, however, with different crystal chemical features. The nickel sites within the AlB₂ slabs are not fully occupied in both indides. Additionally In/Tm mixing is possible at the center of the CsCl slab, as is evident from the structure refinement of Tm_2.22(2)Ni_1.81(1)In_0.78(2). The Mo₅SiB₂ type structures of Tm_4.83(3)Ni₂In_1.17(3) and Er₅Ni₂In can be considered as an intergrowth of distorted CuAl₂ and U₃Si₂ related slabs in an ABA′B′ stacking sequence along the c-axis. Again, one thulium site shows Tm/In mixing. The U₃Si₂ related slab has great structural similarities with the Mo₂FeB₂ type structure of Tm₂Ni_1.896(4)In and Tm_2.22(2)Ni_1.81(1)In_0.78(2). The crystal chemical peculiarities and chemical bonding in these intermetallics are briefly discussed.     

Neutron powder diffraction and magnetic measurements on RbTil3, RbVI3, and CsVI3

CsVI₃ (a = 8.124(1) c = 6.774(1)Å,Z = 2, P6₃/mmc at 293 K) adopts the BaNiO₃ structure. Three-dimensional magnetic ordering takes place atT_c = 32(1)K. At 1.2 K the magnetic moment is 1.64(5) μ_B and it forms a 120° spin structure in the basal plane. RbVI₃ (a = 13.863(2) c = 6.807(1) Å,Z = 6, P6₃cmor P3¯c1 at 293 K) and RbTiI₃ (a = 14.024(3) Å,c = 6.796(2) Å,Z = 6, P6₃cm orP3¯c1 at 293 K) adopt a distorted BaNiO₃ structure, probably isostructural with KNiCl₃.T_c of RbVI₃ is 25(1) K. At 1.2 K, RbVI₃ has a spin structure similar to the one of CsVI₃ with a magnetic moment of 1.44(6) μ_B. RbTiI₃ shows no magnetic ordering at 4.2 K. It is shown that a deviation from the 120° structure is expected for compounds with a distorted BaNiO₃ structure such as RbVI₃. The cell dimensions of CsTiI₃ are reported.     

Open-Framework Cobalt (II) Phosphates with Sodalite-Related Architectures

Three new framework cobalt (II) phosphates have been synthesized hydrothermally in the presence of piperazine as a structure-directing agent. Crystal data: compound I, [C₄N₂H₁₂][Co(HPO₄)₂], monoclinic space group=P2₁/n 001(no. 14), a=8.5521(10) Å, b=13.5791(15) Å, c=10.0405(11) Å, β=96.855(2)°, V=1157.7(2) ų, Z=4, M=339.04, D_c= 1.945 g m−3, MoKα, λ=0.71073 Å, R₁(F₀)=0.053; compound II, [C₄N₂H₁₁][Co₂(PO₄)(H₂PO₄)₂], monoclinic space group=C2/c (no. 15), a=13.444(5) Å, b=12.874(5) Å, c=8.224(2) Å, β=94.64(2)°, V=1418.8 (2)A 3, Z=8, M=494.96, D_c=2.317 g cm−3, MoKα, λ=0.71073 Å ,R₁(F₀)=0.047; compound III, [C₄N₂H₁₂]₂[Co₄(HPO₄)₆], monoclinic space group=P2₁/c (no. 14) a=12.8780(13) Å, b=26.671(3) Å, c=8.2592(8) Å, β=96.931(2)°, V=2816.0(5) Å3, Z=4, M=987.90, D_c=2.330gcm-3, MoKα, λ=0.71073 Å, R₁(F₀)=0.048. The structure of I consists of one-dimensional chains built up of corner-shared four rings (Co₂P₂) which are key structural units that form the sodalite cage. Compounds II and III have interrupted sodalite-type structures resulting from the removal of Co²⁺ atoms from sites related by two-fold axes passing through the four rings of the normal sodalite cage structure. The modes of the interruptions in II and III differ in relation to the structure of a regular sodalite cage.     

Synthesis and crystal structure of three silver indium double phosphates

Three new silver indium double phosphates Ag₃In(PO₄)₂ (I), β-(II) and α-Ag₃In₂(PO₄)₃ (III) were synthesized by solid state method (I and II—700 °C, III—900 °C). Compounds I and II crystallize into a monoclinic system (I—sp. gr. C2/m, Z=2, a=8.7037(1)Å, b=5.4884(1)Å, c=7.3404(1)Å, β=93.897(1)°; II—sp. gr. C2/c, Z=4, a=12.6305(1)Å, b=12.8549(1)Å, c=6.5989(1)Å, β=113.842(1)°), and compound III crystallize into a hexagonal system (sp. gr. R-3c, Z=6, a=8.9943(1)Å, c=22.7134(1)Å). Their crystal structures were determined by the Rietveld analysis (I—R_p=6.47, R_wp=8.54; II—R_p=5.67, R_wp=6.40; III—R_p=7.30, R_wp=9.91). Structure of Ag₃In(PO₄)₂ is related to the sodium chromate structure type and is isotypic to α-Na₃In(PO₄)₂. The polymorphous modifications of β- and α-Ag₃In₂(PO₄)₃ are isostructural to sodium analogs (β- and α-Na₃In₂(PO₄)₃) and are related to alluaudite (II) and NASICON (III) structure types. Compounds I and II are not stable at temperature above 850 °C. Ag₃In(PO₄)₂ is decomposed providing silver orthophosphate Ag₃PO₄ and α-Ag₃In₂(PO₄)₂. β-Ag₃In₂(PO₄)₃ is transformed to α-Ag₃In₂(PO₄)_3.     

Structure and magnetic properties of RE2CuIn3 (RE=Ce, Pr, Nd, Sm and Gd)

The ternary copper indides RE₂CuIn₃≡RECu_0.5In_1.5 (RE=Ce, Pr, Nd, Sm and Gd) were synthesized from the elements in sealed tantalum tubes in an induction furnace. They crystallize with the CaIn₂-type structure, space group P6₃/mmc, with a statistical occupancy of copper and indium on the tetrahedral substructure. These indides show homogeneity ranges RECu_xIn_2−x. Single crystal structure refinements were performed for five crystals: CeCu_0.66In_1.34 (a=479.90(7) pm, c=768.12(15) pm), PrCu_0.52In_1.48 (a=480.23(7) pm, c=759.23(15) pm), NdCu_0.53In_1.47 (a=477.51(7) pm, c=756.37(15) pm), SmCu_0.46In_1.54 (a=475.31(7) pm, c=744.77(15) pm), and GdCu_0.33In_1.67 (a=474.19(7), c=737.67(15) pm). Temperature-dependent susceptibility measurements show antiferromagnetic ordering at T_N=4.7 K for Pr₂CuIn₃ and Nd₂CuIn₃ and 15 K for Sm₂CuIn₃. Fitting of the susceptibility data of the samarium compound revealed an energy gap ΔE=39.7(7) K between the ground and the first excited levels.     

Rare earth metal-rich indides RE14Rh3−xIn3 (RE=Y, Dy, Ho, Er, Tm, Lu)

The rare earth (RE) metal-rich indides RE₁₄Rh_3-xIn₃ (RE=Y, Dy, Ho, Er, Tm, Lu) can be synthesized from the elements by arc-melting or induction melting in tantalum crucibles. They were investigated by X-ray diffraction on powders and single crystals: Lu₁₄Co₃In₃ type, space group P4₂/nmc, Z=4, a=961.7(1), c=2335.5(5) pm, wR2=0.052, 2047 F² values, 62 variables for Y₁₄Rh₃In₃, a=956.8(1), c=2322.5(5) pm, wR2=0.068, 1730 F² values, 63 variables for Dy₁₄Rh_2.89(1)In₃, a=952.4(1), c=2309.2(5) pm, wR2=0.041, 1706 F² values, 63 variables for Ho₁₄Rh_2.85(1)In₃, a=948.6(1), c=2302.8(5) pm, wR2=0.053, 1977 F² values, 63 variables for Er₁₄Rh_2.86(1)In₃, a=943.8(1), c=2291.5(5) pm, wR2=0.065, 1936 F² values, 63 variables for Tm₁₄Rh_2.89(1)In₃, and a=937.8(1), c=2276.5(5) pm, wR2=0.050, 1637 F² values, 63 variables for Lu₁₄Rh_2.74(1)In₃. Except Yb₁₄Rh₃In₃, the 8g Rh1 sites show small defects. Striking structural motifs are rhodium-centered trigonal prisms formed by the RE atoms with comparatively short Rh-RE distances (271-284 pm in Y₁₄Rh₃In₃). These prisms are condensed via common corners and edges building two-dimensional polyhedral units. Both crystallographically independent indium sites show distorted icosahedral coordination. The icosahedra around In2 are interpenetrating, leading to In2-In2 pairs (309 pm in Y₁₄Rh₃In₃).     

Framework polymers based on octahedral chalcocyanide cluster [Re6Q8(CN)6]4−/3− anions (Q = Se, Te) and [Nd(Bipy)n]3+ Complexes (n = 1, 2)

Interaction of salts of the cluster anions {Re [Re₆Q₈(CN)₆]^4?/3? (Q = Se, Te) with Nd salts in the presence of 2,2′-bipyridyl (Bipy) ligand brings about new coordination polymers: Pr ₄ ⁿ N[{Nd(Bipy)(H₂O)₄} {Re₆Se₈(CN)₆}] · 2H₂O (I) (space group C2/c, a = 18.2918(16) Å, b = 14.9972(13) Å, c = 37.513(3) Å, β = 102.046(4)°, V = 10064.2(15) ų, Z = 8), [{Nd(Bipy)₂(H₂O)} {Re₆Se₈(CN)₆}] (II) (space group C2/c, a = 15.8668(3) Å, b = 13.5403(3) Å, c = 20.5189(4) Å, β = 110.135(1)°, V = 4138.89(15) Å₃, Z = 4), and [{Nd(Bipy)(EtOH)(H₂O)₄}{Re₆Te₈(CN)₆}] · EtOH (III) (space group $P\bar 1$ , a = 9.4733(6) Å, b = 12.5326(8) Å, c = 17.2374(11) Å, α = 96.561(2)°, β = 90.310(2)°, γ = 94.876(2)°, V = 4138.89(15) Å₃, Z = 4). The compounds synthesized are characterized by single-crystal X-ray diffraction and IR methods. Compounds I and III have layered (2D) structures, compound II is a framework (3D) polymer.     

Crystal structure of oxo(diperoxo)bipyridylmolybdenum(VI)

Yellow oxo(diperoxo)bipyridylmolybdenum(VI), C₁₀H₈MoN₂O₅, M_r = 332.1 crystallizes in the monoclinic space group P2₁/n, a = 6.261(3), b = 12.726(1) c = 13.752(3)A, β = 91.84(2)°, V = 1095.2(5)A³, Z = 4, D_c = 2.014(1) g/cm³, MoKα(λ = 0.7107A), μ = 11.8 cm^?1, T = 22(1)°C, R = 0.034, ωR = 0.040, number of reflections in least squares (F₀ > 2σ(F₀)) = 1125. The molybdenum coordination (distorted trigonal bipyramidal) is as in the corresponding chromium complex, C₁₀H₈CrN₂O₅ which has closely similar bond angles but is not isomorphous. The difference in MoN_apex and MoN_eq bond distances (2.312(5) and 2.199(5)A) is similar to that in the CrN_apex and CrN_eq distances (2.23(2) and 2.11(2)A). The MO distances for each peroxo ligand (ave. 1.910(2) and 1.950(2)A) are significantly different and slightly longer than those in the chromium complex as is the OO distance of 1.459(6)A. The latter is indicative of greater negative charge on the O₂ ligands, approaching that of O^2?₂ in the molybdenum complex.     

New crystal modification of the di(nitrato)di(aqua)palladium(II) complex β-trans-[Pd(NO3)2(H2O)2]

Single crystals of a new modification of the di(nitrato)di(aqua)palladium(II) complex β-trans-[Pd(NO₃)₂(H₂O)₂] were obtained. Their crystal structure was determined: monoclinic crystal system, a = 5.7469(4) Å, b = 5.3942(6) Å, c = 10.0956(10) Å, β = 97.401(3)°, P2₁/c, Z = 2, d _calc = 2.851 g/cm³, Bruker X8 APEX CCD, MoK _α , 836 independent reflections, room temperature. The square-plane coordination of the Pd atom is formed by four oxygen atoms (Pd-O(NO₃) 2.003(3) Å and Pd-O(H₂O) 2.021(4) Å) and completed to a distorted bipyramid by two intramolecular contacts (Pd…O(NO₃) 2.893 Å). A comparative crystal-chemical analysis with α-trans-[Pd(NO₃)₂(H₂O)₂] was carried out.     

Synthesis, crystal structure and magnetic characterization of metal(II) coordination polymers based on 2-carboxyethylphosphonic acid and 1,10-phenanthroline (metal=Cu, Co, Cd)

Three non-isostructural metal(II) coordination polymers (metal=copper, cobalt, cadmium) were synthesized under the same mild hydrothermal conditions (T=408 K) by mixture of the corresponding metal acetate with 2-carboxyethylphosphonic acid and 1,10-phenanthroline (1:1:1 M ratio) and their structures were determined by single-crystal X-ray diffraction. Cu₂(HO₃PCH₂CH₂COO)₂(C₁₂H₈N₂)₂(H₂O)₂ and Cd₂(HO₃PCH₂CH₂COO)₂(C₁₂H₈N₂)₂ are triclinic (space group P-1) with a=7.908(5) Å, b=10.373(5) Å, c=11.515(5) Å, α=111.683(5)°, β=95.801(5)°, γ=110.212(5)° (T=120 K), and a=8.162(5) Å, b=9.500(5) Å, c=11.148(5) Å, α=102.623(5)°, β=98.607(5)°, γ=113.004(5)° (T=293 K), respectively. In contrast, [Co₂(HO₃PCH₂CH₂COO)₂(C₁₂H₈N₂)₂(μ-OH₂)](H₂O) is orthorhombic (space group Pbcn) with a=21.1057(2) Å, b=9.8231(1) Å, c=15.4251(1) Å (T=120 K). For these three compounds, structural features, including H-bond network and the π-π stacking interactions, and thermal stability are reported and discussed. None of the materials present a long-range magnetic order in the range of temperatures investigated from 300 K down to 1.8 K.     

Syntheses and structural studies on two cycloruthenapentadienyl complexes: [(CO)3RuC4(CH2OH)4]Ru(CO)3·H2O and [(CO)3RuC4(CH2CH2OH)2(C2H5)2]Ru(CO)3

Syntheses and single-crystal X-ray diffraction studies have been completed on two cycloruthenapentadienyl (CO)₆Ru₂L₂ derivatives, with L = CH₂OHC = CCH₂OH and C₂H₅C=CCH₂CH₂OH respectively. Crystal data are as follows: for [(CO)₃RuC₄(CH₂OH)₄]Ru(CO)₃·H₂O, P2₁/c, a 13.72(1), b 9.501(4), c 14.86(1) Å, β 101.10(6)°, R_w = 0.052 for 1911 reflections; for [(CO)₃RuC₄(CH₂CH₂OH)₂(C₂H₅)₂]Ru(CO)₃, P2₁/c, a 9.191(3), b 16.732(4), c 14.903(3) Å, β 113.61(4)°, R_w = 0.042 for 2865 reflections. Both compounds are built up from binuclear units, each unit being regarded as a Ru(CO)₃ fragment π-bonded to a cycloruthenapentadienyl ring. The molecular parameters are compared with those of known cyclometallapentadienyl complexes of transition metals. The presence of a semi-bridging CO group is discussed.