Synthesis and crystal chemistry of NH3(MoO3)3

NH₃(MoO₃)₃ crystallizes with hexagonal symmetry, space group $\text{P6}{}_3\text{m}$, lattice constants a = 10.568 Å, c = 3.726 Å, and Z = 2. The crystal structure has been determined by Patterson synthesis and refined assuming isotropic temperature factors to a final conventional R value of 0.085. The structure shows a three-dimensional arrangement built up of double chains of distorted MoO₆ octahedra, parallel to the [001] direction. The octahedral double chains are linked among each other through common oxygen atoms. In addition to the shared oxygen atoms, each molybdenum is coordinated to one terminal oxygen. MoO distances range from 1.645 to 2.378 Å and OMoO angles from 74.3 to 114.3°. These results are consistent with the fact that molybdenum in high-valence states shows octahedral coordination with terminal oxygens.     

Structure of two new borates YCa3(AlO)3(BO3)4 and YCa3(GaO)3(BO3)4

By replacing Mn in YCa₃(MnO)₃(BO₃)₄ with trivalent Al and Ga, two new borates with the compositions of YCa₃(MO)₃(BO₃)₄ (M=Al, Ga) were prepared by solid-state reaction. Structure refinements from X-ray powder diffraction data revealed that both of them are isostructural to gaudefroyite with a hexagonal space group P6₃/m. Cell parameters of a=10.38775(13)Å, c=5.69198(10)Å for the Al-containing compound and a=10.5167(3)Å, c=5.8146(2)Å for the Ga analog were obtained from the refinements. The structure is constituted of AlO₆ or GaO₆ octahedral chains interconnected by BO₃ groups in the ab plane to form a Kagomé-type lattice, leaving trigonal and apatite-like tunnels. It is found that most rare-earth and Cr, Mn ions can be substituted into the Y³⁺ and M³⁺ sites, respectively, and the preference of rare-earth ions to locate in the trigonal tunnel is correlated to the sizes of the M³⁺ ions.     

Synthesis and characterisation of HRuRh3(CO)12. Crystal structures of HRuRh3(CO)12, HRuRh3(CO)10(PPh3)2 and HRuCo3(CO)10(PPh3)2

A new ruthenium-rhodium mixed-metal cluster HRuRh₃(CO)₁₂ and its derivatives HRuRh₃(CO)₁₀(PPh₃)₂ and HRuCo₃(CO)₁₀(PPh₃)₂ have been synthesized and characterized. The following crystal and molecular structures are reported: HRuRh₃(CO)₁₂: monoclinic, space group P2₁/c, a 9.230(4), b 11.790(5), c 17.124(9) Å, β 91.29(4)°, Z = 4; HRuRh₃(CO)₁₀(PPh₃)₂·C₆H₁₄: triclinic, space group P$\text{1}$, a 11.777(2), b 14.079(2), c 17.010(2) Å, α 86.99(1), β 76.91(1), γ 72.49(1)°, Z = 2; HRuCo₃(CO)₁₀(PPh₃)₂·CH₂Cl₂: triclinic, space group P$\text{1}$, a 11.577(7), b 13.729(7), c 16.777(10) Å, α 81.39(4), β 77.84(5), γ 65.56°, Z = 2. The reaction between Rh(CO)₄^? and (Ru(CO)₃Cl₂)₂ tetrahydrofuran followed by acid treatment yields HRuRh₃(CO)₁₂ in high yield. Its structural analysis was complicated by a 80–20% packing disorder. More detailed structural data were obtained from the fully ordered structure of HRuRh₃(CO)₁₀(PPh₃)₂, which is closely related to HRuCo₃(CO)₁₀(PPh₃)₂ and HFeCo₃(CO)₁₀(PPh₃)₂. The phosphines are axially coordinated.     

Ga3(HPO3)4F4(H3DETA) (DETA=diethylenetriamine): A new open-framework fluorinated gallium phosphite with pentameric building unit

Ga₃(HPO₃)₄F₄(H₃DETA) is a new open-framework fluorinated gallium phosphite obtained by mild hydrothermal synthesis using diethylenetriamine as templated agent and characterized by single crystal X-ray diffraction, the powder X-ray diffraction, IR spectroscopy, TGA, ICP and elemental analyses. It crystallizes in the monoclinic space group C2/c, a=12.741(6) Å, b=12.068(6) Å, c=11.988(5) Å, β=94.902(8)^o, V=1836.6(15) Å³, Z=4. The construction of 3D open-framework structure in the title compound may be viewed as the assembly of pentameric building units and HPO₃ groups. The pentameric building unit is the first to be found, which lead to form the three types of channels along a-, b- and c-axes, respectively, in gallium phosphite. The triprotonated DETA cations are inserted within the 10-membered ring channels and interact with anions of the framework via hydrogen bonds.     

Selective formation of trans and cis(CH3CN) isomers of [Ru(bpy)(CO)2(CH3CN)2] (bpy=2,2-bipyridine) from [Ru(CO)2(CH3CN)3]2(PF6)2 using an electrochemical oxidation step

The selective in situ synthesis of trans and cis(CH₃CN)-[Ru(bpy)(CO)₂ (CH₃CN)₂]²⁺ isomers from the same [Ru(CO)₂ (CH₃CN)₃]₂²⁺ dimer precursor but using either an electrochemical-chemical or chemical-electrochemical process is described.     

The reaction of Ru3(CO)12 and Os3(CO)12 with PH2Ph; the x-ray crystal structures of HRu3(CO)10(PHPh) and H2Ru3(CO)9(PPh)

Twelve new trinuclear complexes containing terminal PH₂Ph, edge-bridging PHPh and/or capping PPh ligands have been isolated from the reaction of M₃(CO)₁₂ (M = Ru or Os) with PH₂Ph in refluxing solvents. HRu₃(CO)₁₀(PHPh) (IIIa) crystallises in the monoclinic space group P2₁/c with a = 8.761(3), b = 11.402(4), c = 22.041(7) Å,β = 98.89(2)°, and Z = 4. The structure was solved by a combination of direct methods and Fourier difference techniques, and refined by blocked-cascade least squares to R = 0.027 for 3676 unique observed intensities. The X-ray analysis shows that one edge of the Ru₃ triangle is bridged by a hydride and the PHPh ligand, and that the phosphorus-bound hydrogen atom lies over the metal triangle and the phenyl group away from it. This provides an explanation for the ready formation of the capped species H₂Ru₃(CO)₉(PPh) (Va) on pyrolysis of the edge-bridged complex as opposed to the previously reported conversion of HOs₃(CO)₁₀(NHPh) to an orthometallated derivative under similar conditions. An X-ray analysis of H₂Ru₃(CO)₉-(PPh) (Va) confirms the capped geometry. the complex crystallises in the monoclinic space group P2₁/n with a = 9.323(4), b = 15.110(6), c = 45.267(15) Å,β = 91.84(3)°, and Z = 12. the structure was solved and refined using the same techniques as described previously. The final residual R is 0.061 for 4839 reflections. Some reactions of Va show that the phosphorous cap is difficult to displace and stabilises the molecule with respect to decomposition to non-cluster species.     

Syntheses, structures, and properties of Ag4(Mo2O5)(SeO4)2(SeO3) and Ag2(MoO3)3SeO3

Ag₄(Mo₂O₅)(SeO₄)₂(SeO₃) has been synthesized by reacting AgNO₃, MoO₃, and selenic acid under mild hydrothermal conditions. The structure of this compound consists of cis-MoO₂²⁺ molybdenyl units that are bridged to neighboring molybdenyl moieties by selenate anions and by a bridging oxo anion. These dimeric units are joined by selenite anions to yield zigzag one-dimensional chains that extended down the c-axis. Individual chains are polar with the C₂ distortion of the Mo(VI) octahedra aligning on one side of each chain. However, the overall structure is centrosymmetric because neighboring chains have opposite alignment of the C₂ distortion. Upon heating Ag₄(Mo₂O₅)(SeO₄)₂(SeO₃) looses SeO₂ in two distinct steps to yield Ag₂MoO₄. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): orthorhombic, space group Pbcm, a=5.6557(3), b=15.8904(7), c=15.7938(7) Å, V=1419.41(12), Z=4, R(F)=2.72% for 121 parameters with 1829 reflections with I>2σ(I). Ag₂(MoO₃)₃SeO₃ was synthesized by reacting AgNO₃ with MoO₃, SeO₂, and HF under hydrothermal conditions. The structure of Ag₂(MoO₃)₃SeO₃ consists of three crystallographically unique Mo(VI) centers that are in 2+2+2 coordination environments with two long, two intermediate, and two short bonds. These MoO₆ units are connected to form a molybdenyl ribbon that extends along the c-axis. These ribbons are further connected together through tridentate selenite anions to form two-dimensional layers in the [bc] plane. Crystallographic data: (193 K; MoKα, λ=0.71073 Å): monoclinic, space group P2₁/n, a=7.7034(5), b=11.1485(8), c=12.7500(9) Å, β=105.018(1) V=1002.7(2), Z=4, R(F)=3.45% for 164 parameters with 2454 reflections with I>2σ(I). Ag₂(MoO₃)₃SeO₃ decomposes to Ag₂Mo₃O₁₀ on heating above 550 °C.     

Zn(C3H3N2)2: a novel diamagnetic insulator

We have prepared polycrystalline samples of Zn(C₃H₃N₂)₂ by a liquid-mix technique. Characterization of the obtained samples has been performed with the aid of elemental, thermogravimetric, infrared spectra and X-ray powder diffraction analysis. We have measured electric permittivity (ε′, ε″), ac-conductivity (σ_ac), magnetic susceptibility (χ) and specific heat (C_p). The obtained data indicate that this material is a new diamagnetic insulator. A maximum around is found in C_pT⁻³, and it is suggested that in addition to the Debye lattice contribution, there exists a low-frequency mode assigned as an Einstein mode contribution to the total specific heat. As a main result of the study, we found ε′ to be constant in a wide temperature range and to have a small value of 2.3 at room temperature. This feature in combination with other properties like crystallization, good thermal stability (up to 400°C), weak moisture sensitivity and simple synthesis makes Zn(C₃H₃N₂)₂ to be a promising candidate for good insulating material in various applications.     

Kristall- und molekülstruktur vonzwei metallcarbonyl-derivaten des PH3: (CO)3Cr(PH3)3 und (CO)5Cr(PH3)

The structures of two carbonylphosphine complexes of chromium were determined by X-ray analysis. cis-Tricarbonyltriphosphinechromium(0), [(CO)₃(PH₃)₃Cr], crystallizes in space group P2₁/m with a = 6.90± 0.01, b = 11.29±0.02, c = 6.41±0.01 Å, β = 93.80±0.08°, Z=2. The structure was solved by conventional methods and refined by least squares (R₁ = 0.056). The idealized octahedral molecule shows approximate C_3v, symmetry. The mean CrP-distance is 2.346±40.003 Å. Pentacarbonylphosphinechromium, [(CO)₅(PH₃)Cr], crystallizes in spacegroup Pnma with a = 12.23±0.02, b = 11.33±0.02, c = 6.61 ±0.01 Å, Z = 4. Cell dimensions and structural parameters are very similar to those of hexacarbonylchromium(0). In the crystal the PH₃ group is disordered over three mutually cis-positions of the coordination octahedron.     

Luminescence properties of efficient X-ray phosphors of YBa3B9O18, LuBa3(BO3)3, α-YBa3(BO3)3 and LuBO3

The samples of YBa₃B₉O₁₈, LuBa₃(BO₃)₃, α-YBa₃(BO₃)₃ and LuBO₃ powders have been synthesized by the solid-state reaction methods at high temperature and their X-ray excited luminescent properties were investigated. All the studied materials show a broad emission band in the wavelength range of 300-550 nm with the peak centers at about 385 nm for YBa₃B₉O₁₈ and LuBa₃(BO₃)₃, 415 nm for α-YBa₃(BO₃)₃ and 360 nm for LuBO₃ powders, respectively. Even though those compounds have the different atomic structures, they have the common structural feature of each yttrium or lutetium ion bonded to six separate BO₃ groups, i.e., octahedral RE(BO₃)₆ (RE=Lu or Y) moiety. This octahedral RE(BO₃)₆(RE=Lu or Y) moiety seems to be an important structural element for efficient X-ray excited luminescence of those compounds, as are the edge-sharing octahedral TaO₆ chains for tantalate emission.     

Hydrothermal Synthesis, Single-Crystal Structure Analysis, and Solid-State NMR Characterization of Zn2(OH)0.14(3)F0.86(3)(PO4)

The zinc fluoro phosphate Zn₂F(PO₄) has been produced by hydrothermal synthesis employing hydrofluoric acid as a mineralizer in a H₂O or D₂O medium. A single-crystal X-ray synchrotron diffraction analysis of Zn₂F(PO₄) shows that the zinc fluoro phosphate is monoclinic, a=9.690(1), b=12.793(1), and c=11.972(1) Å, β=108.265(1)°, space group P2₁/c, No. 14, Z=16. Reflections hkl with k=2n+1 are weak but significant and the structure shows pseudosymmetry. Zn₂F(PO₄) has the wagnerite-type M₂F(XO₄) structure with four Zn atoms each coordinated to four O atoms and one F atom while four other Zn atoms are coordinated to four O atoms and two F atoms. A difference Fourier map, calculated from the single-crystal X-ray data, shows additional electron density close to the four fluorine atoms, indicating a possible partial substitution of F⁻ by OH⁻ ions. This is unambiguously confirmed by ³¹P-{¹H} cross-polarization magic-angle spinning (MAS) and by ¹H/²H MAS NMR spectroscopy. The narrow line width observed for the ¹H resonance and the unique set of ²H quadrupole coupling parameters (obtained for the Zn₂F(PO₄) sample using D₂O as medium) show that ¹H/²H is present as OH(D) groups rather than as water of crystallization in the structure. Quantitative ¹H MAS NMR analysis shows that the composition of the sample is Zn₂(OH)_0.14(3)F_0.86(3)(PO₄). The high-speed ¹⁹F MAS NMR spectrum exhibits two resolved resonances with equal intensity, which are ascribed to an overlap of resonances from the four distinct fluorine sites in Zn₂(OH)_0.14(3)F_0.86(3)(PO₄).     

Bis(trifluoromethyl)dicarbonate, CF3OC(O)OC(O)OCF3

The synthesis of the new compound, bis(trifluoromethyl)dicarbonate, CF₃OC(O)OC(O)OCF₃, is carried out by reduction of bis(trifluoromethyl)trioxidicarbonate with excess of CO at 0 °C. The product is characterized by IR, Raman, ¹³C and ¹⁹F NMR spectroscopy and its properties are compared with those of the other members of the series CF₃OC(O)O_xC(O)OCF₃, x = 0-3. Single crystals are grown at −25 °C and the X-ray diffraction analysis shows the packing of syn-syn rotamers exhibiting C₂ symmetry. DFT calculations predict this rotamer as the most stable one and also structural and vibrational data are predicted reasonably well.     

Non-centrosymmetric Ba3Ti3O6(BO3)2

The compound previously reported as Ba₂Ti₂B₂O₉ has been reformulated as Ba₃Ti₃B₂O₁₂, or Ba₃Ti₃O₆(BO₃)₂, a new barium titanium oxoborate. Small single crystals have been recovered from a melt with a composition of BaTiO₃:BaTiB₂O₆ (molar ratio) cooled between 1100°C and 850°C. The crystal structure has been determined by X-ray diffraction: hexagonal system, non-centrosymmetric space group, a=8.7377(11) Å, c=3.9147(8) Å, Z=1, wR(F²)=0.039 for 504 unique reflections. Ba₃Ti₃O₆(BO₃)₂ is isostructural with K₃Ta₃O₆(BO₃)₂. Preliminary measurements of nonlinear optical properties on microcrystalline samples show that the second harmonic generation efficiency of Ba₃Ti₃O₆(BO₃)₂ is equal to 95% of that of LiNbO₃.     

1-methyl-(D3)-trishomocubane

The acid catalysed rearrangement of 8-methyl-pentacyclo(5.4.0.0^2,6.0^3,10.0^5,9)undecan-8-endo-o1 ($\text{8}$) to 3-methyl-(D₃)-trishomocuban-4-o1 ($\text{9}$) provided the key step to the synthesis of the title compound ($\text{11}$).     

Thiocarbonyl complexes of ruthenium(II). Synthesis of RuCl2(CS)(H2O)(PPh3)2 and RuHCl(CS)(PPh3)3

A high-yield synthesis of trans-RuCl₂(CS)(H₂O)(PPh₃)₂ from RuCl₂(PPh₃)₃ and CS₂ is described. The coordinated water molecule is labile, and introduction of CNR (R  p-toyl or p-chlorophenyl) leads to yellow trans-RuCl₂(CS)(CNR)(PPh₃)₂, which isomerises thermally to colourless cis-RuCl₂(CS)(CNR)(PPh₃)₂. Reaction of AgClO₄ with cis-RuCl₂(CS)(CNR)(PPh₃)₂ gives [RuCl(CS)(CNR)(H₂O)(PPh₃)₂]⁺, from which [RuCl(CS)(CO)(CNR)(PPh₃)₂]⁺ and [RuCl(CS)(CNR)₂(PPh₃)₂]⁺ are derived. Reaction of trans-RuCl₂(CS)(H₂O)(PPh₃)₂ with sodium formate gives Ru(η²-O₂CH)Cl(CS)(PPh₃)₂, which undergoes decarboxylation in the presence of (PPh₃) to give RuHCl(CS)(PPh₃)₃. Ru(η²-O₂CH)H(CS)(PPh₃)₂ and Ru(η²-O₂CMe)-H(CS)(PPh₃)₂ are also described.     

Photoinduced formation of phosphido-bridged clusters derived from Ru3(CO)9(PPh2H)3. Crystal and molecular structure of Ru3(μ-H)(μ-PPh2)3(CO)7

The new complex Ru₃(CO)₉(PPh₂H)₃ (I) was prepared by the direct thermal reaction of Ru₃(CO)₁₂ with PPh₂ H and was spectroscopically characterized. Irradiation of I with λ ≥ 300 nm leads to the formation of Ru₂(μ-PPh₂)₂(CO)₆ (II) and three new phosphido-bridged complexes, Ru₃(μ-H)₂(μ-PPh₂)₂(CO)₈ (III), Ru₃(μ-H)₂(μ-PPh₂)₂(CO)₇(PPh₂H) (IV) and Ru₃(μ-H)(μ-PPh₂)₃(CO)₇ (V). These complexes have been characterized spectroscopically and Ru₃ (μ-H)(μ-PPh₂)₃(CO)₇ by a complete single crystal X-ray structure determination. It crystallizes in the space group P2₁/n with a 20.256(3), b 22.418(6), c 20.433(5) Å, β 112.64(2)°, V 8564(4) ų, and Z = 8. Diffraction data were collected on a Syntex P2₁ automated diffractometer using graphite-monochromatized Mo-K_α radiation, and the structure was refined to R_F 4.76% and R_wF 5.25% for the 8,847 independent reflections with F₀ > 6σ(F₀). The structure consists of a triangular array of Ru atoms with seven terminal carbonyl ligands, three bridging diphenylphosphido ligands which bridge each of the RuRu bonds, and the hydride ligand which bridges one RuRu bond. Complex IV was also shown to give V upon photolysis and is thus an intermediate in the photoinduced formation of V from I.     

Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl₂(PPh₃)₂] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd₃Se(SePh)₃(PPh₃)₃]Cl (1) and [Pd₆Cl₂Se₄(SePh)₂(PPh₃)₆] (2). Complex 1 is triclinic, P1?, a=13.6310(2), b=16.2596(2), c=16.9899(3) Å, α=83.1738(5), β=78.9882(5), γ=78.7635(5)°. Complex 2 is monoclinic, C2/c, a=25.7165(9), b=17.6426(8), c=27.9151(14) Å, β=110.513(2)°. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd₆Cl₂Te₄(TeR)₂(PPh₃)₆] (R=Ph, C₄H₃S) that have been observed as one of the products in the oxidative addition of R₂Te₂ to [Pd(PPh₃)₄]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes.     

Hydro(solvo)thermal synthesis and structural characterization of a new organically templated gallophosphate: [H3N(CH2)2NH3]1/2·[Ga5 (PO4)4(OH)4]

A new three-dimensional open-framework gallophosphate: [H₃N(CH₂)₂NH₃]_1/2·[Ga₅ (PO₄)₄(OH)₄] has been prepared by hydro(solvo)thermal synthesis in presence of ethylenediamine (en) as structure-directing agent. Its structure was determined by means of single-crystal X-ray diffraction analysis with the following crystal data: monoclinic space group C2/m, a=10.1604(9) Å, b=12.0085(15) Å, c=7.1892(7) Å, β=90.797(6)°, V=877.08(16) Å³, Z=2, R₁=0.0264, wR₂=0.0764. The total numbers of measured reflections and unique reflections were 3508 and 1300, respectively. It is built up from a new secondary building unit (SBU) Ga₄P₄O₂₀(OH)₄, in which Ga atoms exhibit distorted trigonal bipyramidal coordination and P atoms are in tetrahedral coordination. The SBU Ga₄P₄O₂₀(OH)₄ are linked into a layer by bridge oxygen atoms. The GaO₄(OH)₂ octahedra link the layers into a three-dimentional framework. Diprotonated ethylenediamine was found in the channel of the framework. The material was characterized by IR spectroscopy, ¹H NMR spectra, thermogravimetric and differential thermal analyses and elemental analysis.     

New open-framework in the uranyl vanadates A3(UO2)7(VO4)5O (A=Li, Ag) with intergrowth structure between A(UO2)4(VO4)3 and A2(UO2)3(VO4)2O

New uranyl vanadates A₃(UO₂)₇(VO₄)₅O (M=Li (1), Na (2), Ag (3)) have been synthesized by solid-state reaction and their structures determined from single-crystal X-ray diffraction data for 1 and 3. The tetragonal structure results of an alternation of two types of sheets denoted S for _∞²[UO₂(VO₄)₂]⁴⁻ and D for _∞²[(UO₂)₂(VO₄)₃]⁵⁻ built from UO₆ square bipyramids and connected through VO₄ tetrahedra to _∞¹[U(3)O₅-U(4)O₅]⁸⁻ infinite chains of edge-shared U(3)O₇ and U(4)O₇ pentagonal bipyramids alternatively parallel to a- and b-axis to construct a three-dimensional uranyl vanadate arrangement. It is noticeable that similar _∞[UO₅]⁴⁻ chains are connected only by S-type sheets in A₂(UO₂)₃(VO₄)₂O and by D-type sheets in A(UO₂)₄(VO₄)₃, thus A₃(UO₂)₇(VO₄)₅O appears as an intergrowth structure between the two previously reported series. The mobility of the monovalent ion in the mutually perpendicular channels created in the three-dimensional arrangement is correlated to the occupation rate of the sites and by the geometry of the different sites occupied by either Na, Ag or Li. Crystallographic data: 293 K, Bruker X8-APEX2 X-ray diffractometer equipped with a 4 K CCD detector, MoKα, λ=0.71073 Å, tetragonal symmetry, space group P4¯m2, Z=1, full-matrix least-squares refinement on the basis of F²; 1,a=7.2794(9) Å, c=14.514(4) Å, R1=0.021 and wR2=0.048 for 62 parameters with 782 independent reflections with I?2σ(I); 3, a=7.2373(3) Å, c=14.7973(15) Å, R1=0.041 and wR2=0.085 for 60 parameters with 1066 independent reflections with I?2σ(I).