Tartrate der TypenLn 2(H2 T)3·xH2O undLnH5 T 2·xH2O einiger Seltenerdmetalle

The following compounds were isolated and more closely studied by means of thermal analysis, X-ray scattering and IR absorption spectra and determination of solubilities: Pr₂(H₂ T)₃ · 6 H₂O, Nd₂(H₂ T)₃ · 6 H₂O, Sm₂(H₂ T)₃ · 5 H₂O, Gd₂(H₂ T)₃ · 5 H₂O, Tb₂(H₂ T)₃ · 5 H₂O, Dy₂(H₂ T)₃ · 5 H₂O, Ho₂(H₂ T)₃ · 5 H₂O, Er₂(H₂ T)₃ · 5 H₂O, PrH₅ T ₂ · 2 H₂O, NdH₅ T ₂ · 2 H₂O, SmH₅ T ₂ · 2 H₂O, GdH₅ T ₂ · 3 H₂O, TbH₅ T ₂ · 3 H₂O, DyH₅ T ₂ · 3 H₂O, HoH₅ T ₂ · 3 H₂O, ErH₅ T ₂ · 3 H₂O.     

Superconducting LaRu2P2 and other alkaline earth and rare earth metal ruthenium and osmium phosphides and arsenides with ThCr2Si2 structure

The ThCr₂Si₂-type compounds MRu₂P₂ (M = Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb), MOs₂P₂ (M = Sr, Ba, Eu), and MRu₂As₂ (M = Ca, Sr, Ba, La, Eu) were prepared by sintering techniques and/or by reaction of the elemental components in a tin flux. The crystal structures of SrRu₂P₂ and LaRu₂P₂ were refined from single-crystal diffractometer data to residuals of R = 0.019 (224 structure factors, 11 variable parameters) and R = 0.028 (510 F's, 11 variables), respectively. LaRu₂P₂ is diamagnetic and becomes superconducting at 4.1 K. No transition to a superconducting state was observed down to 1.8 K for the compounds MFe₂P₂ (M = Ca, Sr, Ba, La), MRu₂P₂ (M = Ca, Sr, Ba, Y), and MOs₂P₂ (M = Sr, Ba).     

Characterization of quasi-one-dimensional S=1/2 Heisenberg antiferromagnets Sr2Cu(PO4)2 and Ba2Cu(PO4)2 with magnetic susceptibility, specific heat, and thermal analysis

Properties of Sr₂Cu(PO₄)₂ and Ba₂Cu(PO₄)₂ having [Cu(PO₄)₂]_∞ linear chains in their structures with Cu-O-P-O-Cu linkages were studied by magnetic susceptibility (T=2-400 K, H=100 Oe) and specific heat measurements (T=0.45-21 K). Magnetic susceptibility versus temperature curves, χ(T), showed broad maxima at T_M=92 K for Sr₂Cu(PO₄)₂ and T_M=82 K for Ba₂Cu(PO₄)₂ characteristic of quasi-one-dimensional systems. The χ(T) data were excellently fitted by the spin susceptibility curve for the uniform S=1/2 chain (plus temperature-independent and Curie-Weiss terms) with g=2.153(4) and J/k_B=143.6(2) K for Sr₂Cu(PO₄)₂ and g=2.073(4) and J/k_B=132.16(9) K for Ba₂Cu(PO₄)₂ (Hamiltonian H=JΣS_iS_i+1). The similar J/k_B values were obtained from the specific heat data. No anomaly was observed on the specific heat from 0.45 to 21 K for both compounds indicating that the temperatures of long-range magnetic ordering, T_N, were below 0.45 K. Sr₂Cu(PO₄)₂ and Ba₂Cu(PO₄)₂ are an excellent physical realization of the S=1/2 linear chain Heisenberg antiferromagnet with k_BT_N/J<0.34% together with Sr₂CuO₃ (k_BT_N/J≈0.25%) and γ-LiV₂O₅ (k_BT_N/J<0.16%). Sr₂Cu(PO₄)₂ and Ba₂Cu(PO₄)₂ were stable in air up to 1280 and 1150 K, respectively.     

The electronic structure of FeO 4 2− , RuO4, RuO 4 − , RuO 4 2− and OsO4 by the HFS-DVM method

The electronic structures of FeO ₄ ^2? , RuO₄, RuO ₄ ^? , RuO ₄ ^2? and OsO₄ have been investigated using the Hartree-Fock-Slater Discrete Variational Method. The calculated ordering of the valence orbitals is 2t ₂, 1e, 2a ₁, 3t ₂ andt ₁ with thet ₁ orbital as the highest occupied. The first five charge transfer bands are assigned as:t ₁→2e(v ₁), 3t ₂→2e(v ₂),t ₁→4t ₂(v ₃), 3t ₂→4t ₂(v ₄) and 2a ₁→4t ₂(v ₅). It is suggested that ad-d transition should be observed at 1.5 eV in RuO ₄ ^? and RuO ₄ ^2? .     

Synthesis of a new class of unsymmetrical PCP′ pincer ligands and their palladium (II) complexes: X-ray structure determination of PdCl{C6H3-2-CH2PPh2-6-CH2PBu2}

The unsymmetrical PCP′ pincer ligands {C₆H₄-1-CH₂PPh₂-3-CH₂PBu^t₂} and {C₆H₄-1-CH₂PPh₂-3-CH₂PPrⁱ₂} and the corresponding palladium complexes: PdCl{C₆H₃-2-CH₂PPh₂-6-CH₂PBu^t₂} and PdCl{C₆H₃-2-CH₂PPh₂-6-CH₂PPrⁱ₂} have been synthesized in good yields. The molecular structure of PdCl{C₆H₃-2-CH₂PPh₂-6-CH₂PBu^t₂} was determined through a single crystal X-ray diffraction study. The palladium center was found to be located into a slightly distorted square planar environment in which the {C₆H₄-1-CH₂PPh₂-3-CH₂PBu^t₂} ligand is coordinated as a tridentate, PCP pincer type chelate. The complex, PdCl{C₆H₃-2-CH₂PPh₂-6-CH₂PPrⁱ₂} catalyzes the Heck coupling of iodobenzene with styrene.     

Synthesis, structure and reactivity of binuclear metal-metal bonded molybdenum(V) and tungsten(V) thioselenohalides: Molecular structure of Mo2(μ-S2)2Cl6(SeCl2)2 and W2(μ-S2)2Cl6(SeCl2)2

Thioselenohalide complexes Mo₂(μ-S₂)₂Cl₆(SeCl₂)₂ (I), Mo₂(μ-S₂)₂Br₆(SeBr₂)₂ (II), and W₂(μ-S₂)₂Br₆(SeBr₂)₂ (III) were synthesized by the reactions of corresponding metal halides or carbonyls or molybdenum metal with excesses of S₂ X ₂+Se₂ X ₂ mixtures. The complex W₂(μ-S₂)₂Cl₆(SeCl₂)₂ (IV) was obtained by an exchange reaction between (III) and excess of Se₂Cl₂. Coordination of the neutral SeX ₂ ligands to thiohalidesM ₂(μ-S₂)₂ X ₆ results in higher thermal stability, and suggests the possibility to synthesize SeX ₂ complexes of the unstable parent tungsten thiohalides. An unusual oxidative addition reaction of (I) was detected: {fx27-1} Both (I) and (IV) were characterized by X-ray crystal structure analysis. They are isostructural and form discrete molecules. Bridging S ₂ ^2? ligands are coordinated perpendicularly to the metal-metal bond;d(M?M)=2.8066 Å and 2.793 Å for I and IV, respectively. Nonequivalence of chlorine atoms which are bound to the metal atom, relate to nonequivalence of halogen atoms in the complexesM ₂(μ?S₂)₂ X ₈ ^2? . Chlorine atomstrans to SeCl₂ ligands form short bonds with the metal; the corresponding³⁵Cl NQR frequency is increased. The selenium dichloride ligand is ambidentate. The selenium atom binds as a donor to the metal and as an acceptor to two chlorine atoms which are also bound covalently to the same metal atom.     

New three-dimensional inorganic frameworks based on the uranophane-type sheet in monoamine templated uranyl-vanadates

Seven new uranyl vanadates with mono-protonated amine or tetramethylammonium used as structure directing cations, (C₂NH₈)₂{[(UO₂)(H₂O)][(UO₂)(VO₄)]₄}·H₂O (DMetU5V4) (C₂NH₈){[(UO₂)(H₂O)₂][(UO₂)(VO₄)]₃}·H₂O (DMetU4V3), (C₅NH₆)₂{[(UO₂)(H₂O)][(UO₂)(VO₄)]₄}·H₂O (PyrU5V4), (C₃NH₁₀){[(UO₂)(H₂O)₂][(UO₂)(VO₄)]₃}·H₂O (isoPrU4V3), (N(CH₃)₄){[(UO₂)(H₂O)₂][(UO₂)(VO₄)]₃}·H₂O (TMetU4V3), (C₆NH₁₄){[(UO₂)(H₂O)₂][(UO₂)(VO₄)]₃}·H₂O (CHexU4V3), and (C₄NH₁₂){[(UO₂)(H₂O)][(UO₂)(VO₄)]₃} (TButU4V3) were prepared from mild-hydrothermal reactions using dimethylamine, pyridine, isopropylamine, tetramethylammonium hydroxide, cyclohexylamine and tertiobutylamine, respectively, with uranyl nitrate and vanadium oxide in acidic medium. The structures were solved using single-crystal X-ray diffraction data. The compounds exhibit three-dimensional uranyl-vanadate inorganic frameworks built from uranophane-type uranyl-vanadate layers pillared by uranyl polyhedra with cavities in between occupied by protonated organic moieties. In the uranyl-vanadate layers the orientations of the vanadate tetrahedra give new geometrical isomers leading to unprecedented pillared systems and new inorganic frameworks with U/V=4/3. Crystallographic data: (DMetU5V4) orthorhombic, Cmc2₁ space group, a=15.6276(4), b=14.1341(4), c=13.6040(4) Å; (DMetU4V3) monoclinic, P2₁/n space group, a=10.2312(4), b=13.5661(7), c=17.5291(7) Å, β=96.966(2); (PyrU5V4), triclinic, P1 space group, a=9.6981(3), b=9.9966(2), c=10.5523(2) Å, α=117.194(1), β=113.551(1), γ=92.216(1)°; (isoPrU4V3) monoclinic, P2₁/n space group, a=10.3507(1), b=13.6500(2), c=17.3035(2) Å, β=97.551(1)°; (TMetU4V3) orthorhombic, Pbca space group, a=17.1819(2), b=13.6931(1), c=21.4826(2) Å; (CHexU4V3), triclinic P−1 space group, a=9.8273(6), b=11.0294(7), c=12.7506(8) Å, α=98.461(3), β=96.437(3), γ=105.955(3)°; (TButU4V3), monoclinic, P2₁/m space group, a=9.8048(4), b=17.4567(8), c=15.4820(6) Å, β=106.103(2).     

Influence of Oxygen Nonstoichiometry on the Spectral Properties of Solid Solutions LaNb2−2xTa2xVO9−δ (x=0-0.4) and LaTa2−2xNb2xVO9−δ (x=0-0.1)

Phase equilibria in the LaVO₄-Nb₂O₅-Ta₂O₅ system were analyzed. New solid solutions LaTa_2−2xNb_2xVO_9−δ (x=0-0.1) and LaNb_2−2xTa_2xVO_9−δ (x=0-0.4) were detected in this system. The structures of the vanadate-niobate LaNb₂VO₉ and vanadate-tantalate LaTa₂VO₉ are not known. The structures of the vanadate-tantalate LaTa₂VO₉ and LaTa₂VO₉-based solid solutions are similar to the structure of LaTa₇O₁₉, which refers to the hexagonal crystal system. The influence of the oxygen nonstoichiometry δ(x) on crystallochemical characteristics and spectral properties of these solid solutions were examined by the X-ray phase analysis, IR and radio spectroscopic methods. A correlation between the nonstoichiometry δ(x) and the volume of a unit cell V(x) of solid solutions LaTa_2−2xNb_2xVO_9−δ was found. The IR spectrum of LaTa₂VO_9−δ transformed in going from δ=0 to δ≠0. Two types of VO₄ tetrahedra were formed in solid solutions LaNb_2−2xTa_2xVO_9−δ depending on δ(x).     

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.     

1,4-dicyanobutene-bridged binuclear rhodium(I) complexes and their catalytic activities

Reactions of Rh(ClO₄)(CO)(PPh₃)₂ with dicyano olefins, cis-NCCHCH-CH₂CH₂CN (c-DC1B), rans-NCCHCHCH₂CH₂CN (t-DC1B), trans-NCCH₂CHCHCH₂CN (t-DC2B), and NCCH₂CH₂CH₂CN (DCB) produce the binuclear dicationic rhodium(I) complexes, [(CO)(PPh₃)₂RhNCACNRh-(PPh₃)₂(CO)](ClO₄)₂ (NCACN = c-DC1B 1), t-DC1B (2), t-DC2B (3), DCB (4). Complexes 1 and 2 are catalytically active for the hydrognation of c-DC1B and t-DC1B, respectively, to give DCB, while complex 3 catalyze the isomerization of t-DC2B to give c-DC1B and t-DC1B, and the hydrogenation of t-DC2B to DCB at 100°C.     

Reactions of the Dirhenium(II) Complexes Re2 X 4(μ-dppm)2 (X=Cl, Br; dppm=Ph2PCH2PPh2) with Isocyanides. Part XV: A Fifth Structural Isomer of the [Re2Cl3(μ-dppm)2(CO)(CNXyl)2]+ Cation (Xyl = 2, 6-Dimethylphenyl)

The reaction of the unsymmetrical, coordinatively unsaturated dirhenium(II) complex [(XylNC)(OC)CIRe(μ-dppm)₂ReCl₂]O₃SCF₃ (dppm = Ph₂PCH₂PPh₂) with one equivalent of XylNC in CH₂Cl₂ affords a fifth structural isomer of the [Re₂Cl₃(μ-dppm)₂(CO)(CNXyl)₂] ⁺ cation; this is believed to have a CO-bridged structure of the type [(XylNC)ClRe(μ-Cl)(μ-CO)(μ-dppm)₂ReCl(CNXyl)]⁺. The latter complex reacts with a further equivalent of XylNC in the presence of Tl⁺ to form the [Re₂Cl₂(μ-dppm)₂(CO)(CNXyl)₃]²⁺ cation, which has been shown by IR spectroscopy, and by the X-ray crystallographic characterization of its neutral congener Re₂Cl₂(μ-dppm)₂(CO)(CNXyl)₃, to contain a very weak and unsymmetrical CO bridge.     

Magnetostructural correlations in heteroleptic nickel(II) complexes

Heteroleptic nickel(II) complexes with the general formula Ni(L)_m(H₂O)_n(X)_k, have been synthesized and structurally characterized; L stands for neutral N-donor ligands: 4-benzofuropyridine (bzfupy), dimethylfuropyridine (Me₂fupy) and 1,2-dimethylimidazole (Me₂iz), X = acetate or Cl⁻. The structures of the complexes [Ni(bzfupy)₂(ac)₂(H₂O)₂], [Ni(Me₂fupy)₂(H₂O)₄](ac)₂ and [Ni(Me₂iz)₄(H₂O)₂]Cl₂ · 3H₂O are formed from {NiO₂O′₂N₂}, {NiO₄N₂} and {NiN₄O₂} chromophores, respectively. These complexes and two other previously characterized complexes, [Ni(pz)₄(ac)₂], pz – pyrazole, and [Ni(L^NN)₂(H₂O)₂], L^NN – bidentate chelating ligand, were subjected to magnetochemical investigation down to 2 K (susceptibility and magnetization measurements). They show magnetic behaviour typical for zero-field splitting systems. The axial parameter of the zero-field splitting, D, adopts either positive or negative values and correlates with the axial distortion of the coordination polyhedra.     

Extraction of selected metallic cations by two sterically hindered di-acidic phosphorus-based extractants, (GO)PO(OH)2

The extraction of Eu³⁺, Am³⁺ and UO₂²⁺ from an aqueous acidic chloride phase into a solution of a phosphorus-based extractant of the type (GO)PO(OH)₂, where G is 2,6-dimethyl heptyl-4 or 2,6,8-trimethyl nonyl-4, has been studied as a function of concentration of the extractant in the organic phase and of the hydrogen ion in a 1.0 F (NaCl + HCl) aqueous phase. The “nonyl” and “dodecyl” compounds are respectively represented as H₂M(DIBM)P and H₂M(2,6,8-TM-N-4)P. In systems employing benzene as the carrier diluent, the extraction stoichiometries, where H₂Y represents either of the extractants, are: M_A³⁺ + 2H₂Y)_po ⇌ M(H_4p−3Y_2p)_O + 3H_A⁺, K_S=K[H⁺]³/F²UO₂²⁺ + 2H₂Y)_po ⇌ UO₂(H_4p−2Y_2p)_O + 2H_A⁺, K_S=K[H⁺]²/F² In systems employing n-heptane as carrier diluent and H₂M(2,6,8-TM-N-4)P as extractant, the stoichiometries are: M_A³⁺ + H₂Y)_po ⇌ M(H_2p−3Y_q)_O + 3H_A⁺, K_s=K[H⁺]³/F²UO₂²⁺ + H₂Y)_qo ⇌ UO₂(H_2q−2Y_q)_O + 2H_A⁺, K_S=K[H⁺]²/F² The K_s values, nine in all, for UO₂²⁺, Am³⁺ and Eu³⁺ in the system H₂Y in carrier diluent vs an aqueous 1.0 F (NaCl + HCl) phase have been calculated.     

A one-dimensional organic-inorganic hybrid based on the bimolecular {[Cu(en)2]2[Cu2Si2W22O78]} polyoxometalate

A one-dimensional coordination polymer [Cu(en)₂]₂[Cu(en)₂(H₂O)]₂{[Cu(en)₂]₂[Cu₂Si₂W₂₂O₇₈]}·4.5H₂O (en=ethylenediamine), which represents the first example of one-dimensional organic-inorganic hybrid based on the bimolecular Keggin polyoxometalates {[Cu(en)₂]₂[Cu₂Si₂W₂₂O₇₈]}⁸⁻ has been hydrothermally synthesized and characterized by elemental analyses, IR, TG and single crystal X-ray diffraction. Crystal data: C₂₄H₈₅Cu₈N₂₄O_84.5Si₂W₂₂, monoclinic, P2₁/c, a=18.8126(3), b=23.0896(4), c=26.0711(4) Å, β=96.3790(10)°, V=11254.5(3) Å³, T=293(2) K; Z=4, μ=23.983 mm⁻¹, R₁=0.0628, wR₂=0.1210 [I>2σ], R₁=0.0854, wR₂=0.1285 (all data ).     

The crystal structure of the monohydrate R2Mo6O21·H2O (R=Pr, Nd, Sm, and Eu): a layer structure containing disordered [Mo2O7] groups

Although R₂O₃:MoO₃=1:6 (R=rare earth) compounds are known in the R₂O₃-MoO₃ phase diagrams since a long time, no structural characterization has been achieved because a conventional solid-state reaction yields powder samples. We obtained single crystals of R₂Mo₆O₂₁·H₂O (R=Pr, Nd, Sm, and Eu) by thermal decomposition of [R₂(H₂O)₁₂Mo₈O₂₇]·nH₂O at around 685-715 °C for 2 h, and determined their crystal structures. The simulated XRD patterns of R₂Mo₆O₂₁·H₂O were consistent with those of previously reported R₂O₃:MoO₃=1:6 compounds. All R₂Mo₆O₂₁·H₂O compounds crystallize isostructurally in tetragonal, P4/ncc (No. 130), a=8.9962(5), 8.9689(6), 8.9207(4), and 8.875(2) Å; c=26.521(2), 26.519(2), 26.304(2), and 26.15(1) Å; Z=4; R₁=0.026, 0.024, 0.024, and 0.021, for R=Pr, Nd, Sm, and Eu, respectively. The crystal structure of R₂Mo₆O₂₁·H₂O consists of two [Mo₂O₇]²⁻-containing layers (A and B layers) and two interstitial R(1)³⁺ and R(2)³⁺ cations. Each [Mo₂O₇]²⁻ group is composed of two corner-sharing [MoO₄] tetrahedra. The [Mo₂O₇]²⁻ in the B layer exhibits a disorder to form a pseudo-[Mo₄O₉] group, in which four Mo and four O sites are half occupied. R(1)³⁺ achieves 8-fold coordination by O²⁻ to form a [R(1)O₈] square antiprism, while R(2)³⁺ achieves 9-fold coordination by O²⁻ and H₂O to form a [R(2)(H₂O)O₈] monocapped square antiprism. The disorder of the [Mo₂O₇]²⁻ group in the B layer induces a large displacement of the O atoms in another [Mo₂O₇]²⁻ group (in the A layer) and in the [R(1)O₈] and [R(2)(H₂O)O₈] polyhedra. A remarkable broadening of the photoluminescence spectrum of Eu₂Mo₆O₂₁·H₂O supported the large displacement of O ligands coordinating Eu(1) and Eu(2).     

Synthesis and X-ray structure of two isomeric aminocarbene complexes of tungsten containing a free carbon-carbon double bond

The reaction of allylamine with (CO)₅WC(OCH₂CH₃)CH₃ gives two isomeric aminocarbene complexes (CO)₅WC(NHCH₂CHCH₂)CH₃ 2E and 2Z. Refluxing of a solution of this mixture in benzene gives the complexes (CO)₄WC(η²NHCH₂CHCH₂)CH₂ (3) and 2E, which have been separated. 2E was fully characterized by X-ray diffraction. Crystals of 2E are monoclinic, space group P2₁/n with Z = 4, a 7.188(3), b 14.312(2), c 12.530(2) Å and β 91.06(3)°.The same mixture when treated with lithium diisopropylamide (LDA) followed by allyl bromide gives a mixture of (CO)₅WC(N(CH₂CHCH₂)₂)CH₃ (4) and 2Z. These complexes were separated, and 2Z fully characterized by X-ray diffraction. Crystals of 2Z are monoclinic, space group P2₁/c, with Z = 4, a 6.593(5), b 14.584(3), c 13.323(1) Å and β 95.13(4)°.     

Syntheses, structures, characterizations and charge-density matching of novel amino-templated uranyl selenates

Five hybrid organic-inorganic uranyl selenates have been synthesized, characterized and their structures have been determined. The structure of (C₂H₈N)₂[(UO₂)₂(SeO₄)₃(H₂O)] (EthylAUSe) is monoclinic, P2₁, a=8.290(1), b=12.349(2), c=11.038(2) Å, β=104.439(4)°, V=1094.3(3) Å³, Z=2, R₁=0.0425. The structure of (C₇H₁₀N)₂[(UO₂)(SeO₄)₂(H₂O)]H₂O (BenzylAUSe) is orthorhombic, Pna2₁, a=24.221(2), b=11.917(1), c=7.4528(7) Å, V=2151.1(3) Å³, Z=4, R₁=0.0307. The structure of (C₂H₁₀N₂)[(UO₂)(SeO₄)₂(H₂O)](H₂O)₂ (EDAUSe) is monoclinic, P2₁/c, a=11.677(2), b=7.908(1), c=15.698(2) Å, β=98.813(3)°, V=1432.4(3) Å³, Z=4, R₁=0.0371. The structure of (C₆H₂₂N₄)[(UO₂)(SeO₄)₂(H₂O)](H₂O) (TETAUSe) is monoclinic, P2₁/n, a=13.002(2), b=7.962(1), c=14.754(2) Å, β=114.077(2)°, V=1394.5(3) Å³, Z=4, R₁=0.0323. The structure of (C₆H₂₁N₄)[(UO₂)(SeO₄)₂(HSeO₄)] (TAEAUSe) is monoclinic, P2₁/m, a=9.2218(6), b=12.2768(9), c=9.4464(7) Å, β=116.1650(10)°, V=959.88(12) Å³, Z=2, R₁=0.0322. The inorganic structural units in these compounds are composed of uranyl pentagonal bipyramids and selenate tetrahedra. In each case, tetrahedra link bipyramids through vertex-sharing, resulting in chain or sheet topologies. The charge-density matching principle is discussed relative to the orientations of the organic molecules between the inorganic structural units.     

Syntheses, structures, optical properties, and theoretical calculations of Cs2Bi2ZnS5, Cs2Bi2CdS5, and Cs2Bi2MnS5

Three new compounds, Cs₂Bi₂ZnS₅, Cs₂Bi₂CdS₅, and Cs₂Bi₂MnS₅, have been synthesized from the respective elements and a reactive flux Cs₂S₃ at 973 K. The compounds are isostructural and crystallize in a new structure type in space group Pnma of the orthorhombic system with four formula units in cells of dimensions at 153 K of a=15.763(3), b=4.0965(9), c=18.197(4) Å, V=1175.0(4) Å³ for Cs₂Bi₂ZnS₅; a=15.817(2), b=4.1782(6), c=18.473(3)  Å, V=1220.8(3)  ų for Cs₂Bi₂CdS₅; and a=15.830(2), b=4.1515(5), c=18.372(2) Å, V=1207.4(2) Å³ for Cs₂Bi₂MnS₅. The structure is composed of two-dimensional _∞²[Bi₂MS₅²⁻] (M=Zn, Cd, Mn) layers that stack perpendicular to the [100] axis and are separated by Cs⁺ cations. The layers consist of edge-sharing _∞¹[Bi₂S₆⁶⁻] and _∞¹[MS₃⁴⁻] chains built from BiS₆ octahedral and MS₄ tetrahedral units. Two crystallographically unique Cs atoms are coordinated to S atoms in octahedral and monocapped trigonal prismatic environments. The structure of Cs₂Bi₂MS₅, is related to that of Na₂ZrCu₂S₄ and those of the AMM′Q₃ materials (A=alkali metal, M=rare-earth or Group 4 element, M′= Group 11 or 12 element, Q=chalcogen). First-principles theoretical calculations indicate that Cs₂Bi₂ZnS₅ and Cs₂Bi₂CdS₅ are semiconductors with indirect band gaps of 1.85 and 1.75 eV, respectively. The experimental band gap for Cs₂Bi₂CdS₅ is ≈1.7 eV, as derived from its optical absorption spectrum.     

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.     

Reaction chemistry of tricarbonyl-η-pentadienylmanganese: Straightforward synthesis of stable manganese carbonyl terminal thiolates and a dinuclear bis(ethylenediaminyl) complex

Tricarbonyl-η⁵-pentadienylmanganese reacts with mercaptans RSH, R = Ph, C₆F₅, m-NH₂C₆H₄, p-NH₂C₆H₄, and HSCH₂CH₂ in the presence of ECH₂CH₂E, E = -PPh₂ or -NH₂ to give novel stable terminal thiolate mononuclear complexes fac-Mn(CO)₃(SR)(Ph₂PCH₂CH₂PPh₂-κ²-P,P′) for R = Ph, C₆F₅, m-NH₂C₆H₄, p-NH₂C₆H₄, and HSCH₂CH₂ and fac-Mn(CO)₃(SR)(H₂NCH₂CH₂NH₂-κ²-N,N′) for R = Ph and C₆F₅. Upon reaction of tricarbonyl-η⁵-pentadienylmanganese with ethylenediamine a dinuclear complex [fac-Mn(CO)₃(μ-H₂NCH₂CH₂NH-κ²-N,N′)]₂ was formed wherein the diaminyl ligand functions in the capacity of chelating and bridging ligand.