Hexaaquacobalt(II) bis(hypophosphite) and hexaaquacobalt(II)/nickel(II) bis(hypophosphite)

The title compounds, hexa­aqua­cobalt(II) bis­(hypophosphite), [Co(H₂O)₆](H₂­PO₂)₂, and hexa­aqua­cobalt(II)/nickel(II) bis(hypophosphite), [Co_0.5Ni_0.5(H₂O)₆](H₂PO₂)₂, are shown to adopt the same structure as hexa­aqua­magnesium(II) bis­(hypophosphite). The packing of the Co(Ni) and P atoms is the same as in the structure of CaF₂. The Co^II(Ni^II) atoms have a pseudo‐face‐centred cubic cell, with a = b～ 10.3 Å, and the P atoms occupy the tetrahedral cavities. The central metal cation has a slightly distorted octahedral coordination sphere. The geometry of the hypophosphite anion in the structure is very close to ideal, with point symmetry mm2. Each O atom of the hypophosphite anion is hydrogen bonded to three water mol­ecules from different cation complexes, and each H atom of the hypophosphite anion is surrounded by three water mol­ecules from further different cation complexes.     

Ammonium bis(tetraethylammonium) hexacyanidoferrate(III) trihydrate

In the structure of the title salt, (NH₄)(C₈H₂₀N)₂[Fe(CN)₆]·3H₂O, the O atom of one of the water molecules shares its crystallographic site with the N atom of the ammonium cation in a 1:1 ratio. The second O atom from the two crystallographically independent water molecules is disordered over two positions separated by 0.551 (1) Å. The water molecules and ammonium cations form tetrameric hydrogen‐bonded units that, along with the complex anion, form the hydrophilic part of the structure. The hydrophobic part of the structure, represented by the tetraethylammonium cation, is located in cube‐like cavities of the hydrophilic framework.     

Photoelectron spectroscopy and density functional theory study of TiAlO(y) (-) (y=1-3) and TiAl(2)O(y) (-) (y=2-3) clusters

Small titanium-aluminum oxide clusters, TiAlO(y) (-) (y=1-3) and TiAl(2)O(y) (-) (y=2-3), were studied by using anion photoelectron spectroscopy. The adiabatic detachment energies of TiAlO(y) (-) (y=1-3) were estimated to be 1.11±0.05, 1.70±0.08, and 2.47±0.08eV based on their photoelectron spectra; those of TiAl(2)O(2) (-) and TiAl(2)O(3) (-) were estimated to be 1.17±0.08 and 2.2±0.1eV, respectively. The structures of these clusters were determined by comparison of density functional calculations with the experimental results. The structure of TiAlO(-) is nearly linear with the O atom in the middle. That of TiAlO(2) (-) is a kite-shaped structure. TiAlO(3) (-) has a kite-shaped TiAlO(2) unit with the third O atom attaching to the Ti atom. TiAl(2)O(2) (-) has two nearly degenerate Al-O-Ti-O-Al chain structures that can be considered as cis and trans forms. TiAl(2)O(3) (-) has two low-lying isomers, kite structure and book structure. The structures of these clusters indicate that the Ti atom tends to bind to more O atoms.     

Nitrosodicyanmethanid-Komplexe von Palladium(II) und Platin(II)

Crystal and Molecular Structure of 1,8-Dihydroxy-3,6-dithiaoctan-bis-mercury(II) Chloride The crystal structure of 1,8-dihydroxy-3,6-dithiaoctane-bis-mercury(II) chloride has been determined by X-ray crystal structure analysis. The compound crystallizes monoclinic, space group C2/c with a = 15.311(2), b = 5.870(2), c = 17.479(2) Å, β = 102.76° and 4 formula units per unit cell. The structure was solved by heavy atom technique and refined to a final R value of R = 0.050. Mercury is digonally coordinated by an S and a Cl ligator. In consequence of weak interactions to an oxygen atom of the ligand as well as to three further Cl ions the coordination number is increased to six and a strongly distorted octahedron is formed. The crystal structure is built up from polymeric complex molecules.     

金属间化物（Sm_（1－x）Y_x）_2Fe_（17）N_y中的各向异性机制探讨

通过Ｘ射线衍射和穆斯堡尔谱等手段研究金属间化物（Ｓｍ１－ｘＹｘ）２Ｆｅ１７Ｎｙ中的各向异性产生机制。结果表明，（１）Ｓｍ次格子的单轴各向异性较强，对总的各向异性贡献起主导机制；（２）Ｎ原子的占位与自旋磁结构密切相关，而与晶体结构无关，Ｎ原子的双重占位导致单轴各向异性；（３）Ｙ原子的择优占位导致晶体结构的变化，而对各向异性影响较小。     

X-ray crystal structure of manganese(II) bis(ethylenediphosphinetetraacetato)nickelate(II) hexadecahydrate

X-ray structure analysis of the title compound (diffractometer data, R = 0.061 for 2805 reflections) confirmed the structure proposed on the basis of spectral evidence for the series of isostructural complexes, M₃[NiL₂ (H₂O)₁₆, where H₄L = (HO₂CCH₂)₂PCH₂CH₂P(CH₂CO₂H)₂ and M = Mn, Fe, Co, Ni, Zn or Cd. The compound studied is monoclinic, P2₁/c, a = 9.990(3), b = 28.51(2), c = 14.828(9) Å, β =94.50(5)°, Z = 4. Nickel(II) is coordinated by two P,P-chelating ligand anions in a rather distorted square planar environment. The carboxyl groups of the ligand are not coordinated to nickel; three of them remain free and five are bonded, together with 10 of the total of 16 water molecules, to the manganese(II) ions. The environments of three manganese ions thus formed are all nearly octahedral but differ in the number and bonding mode of the carboxyls (monodentate and/or bridging bidentate). The carboxyl-to-manganese bonds produce a three-dimensional structure of the compound which is further stabilized by hydrogen bonding.     

Structure of Diacetato bis (2,4,6 Trimethyl Pyridine) Copper(II)

(2.4.6 trimethyl pyridine)₂ Cu(CH₃COO)₂ has been obtained as violet needles by slow evaporation. The crystals belong to the monoclinic system, space group P2_1/C with two molecules in a unit cell of dimension: a = 7.842 (1), b = 16.384 (2), c = 8.320 (2) Å, β = 101.91 (1)°. The structure was solved by heavy atom method and refined by a least squares method (R = 0.029). The coordination of copper is 4 + 2. The atom arrangements of this structure is very near to the copper acetate one solvated by one water molecule and two 3.4 dimethyl pyridine molecules.     

Iron(III) dihydrogenphosphate(I)

The structure of rhombohedral (R) iron(III) tris­[di­hydrogen­phosphate(I)] or iron(III) hypophosphite, Fe(H₂PO₂)₃, has been determined by single‐crystal X‐ray diffraction. The structure consists of [001] chains of Fe³⁺ cations in octa­hedral sites with symmetry bridged by bidentate hypophosphite anions.     

Synthesis and structure of trans-diaquabis(dimethylsulfoxide)bis(3,5-dinitrobenzoato)copper(II)

Single crystal of [Cu(DMSO)₂(3,5-DNB)₂(OH₂)₂], where DMSO-dimethylsulfoxide, 3,5-DNB-3,5-dinitrobenzoate, has been synthesized and its crystal structure is determined. Crystals belong to monoclinic symmetry, space group is P2₁/n, Z = 2, a = 10.911(4) Å, b = 5.362(2) Å, c = 22.673(7) Å, β = 92.06(2)°, V = 1325.8(1) ų, T = 293 K. Final value of R = 0.040 was obtained for 1804 independent reflections with I > 3σ(I). The structure is built from complex molecules.     

Crystal structure of bis(triphenylphosphine) bis(N,N′-dibutylthiourea)silver(I) nitrate

A mixed-ligand silver(I) complex of triphenylphosphine and N,N′-dibutylthiourea (Dbtu), [Ag(Ph₃P)₂(Dbtu)₂]NO₃, is prepared and its structure in the solid state is determined by X-ray crystallography. X-ray structure of this complex shows that it is mononuclear with the silver atom coordinated by two PPh₃ and two dibutylthiourea ligands adopting a distorted tetrahedral geometry. The crystal structure shows the formation of 1-D chains through intermolecular hydrogen bonding interactions between N-H of Dbtu and nitrate ions. The new complex is also characterized by IR and NMR (¹H and ³¹P) spectroscopy. The spectroscopic data are discussed in terms of the nature of bonding. A similar mixedligand complex is also prepared for tetramethylthiourea (Tmtu), but the structure of the resulting compound shows that it is a bis(phosphine) complex, [Ag(PPh₃)₂NO₃] rather than a mixed-ligand complex.     

Biomimetic oxovanadium(IV) and (V) complexes with a tridentate (N,N,O)-donor hydrazonic ligand. Two X-ray crystal structure modifications of (2-acetylpyridine-benzoylhydrazonato)dioxovanadium(V)

Two oxovanadium(IV) and (V) complexes with 2-acetylpyridine-benzoylhydrazone have been prepared and characterized. The analytical methods used included elemental analysis, i.r., FAB⁺ m.s., ⁵¹V-n.m.r. and e.p.r. X-ray diffractometry from single crystals as well as from microcrystalline material were also performed. Molecular modeling was used to calculate the complex structures in a vacuum and their vibrational frequencies. Octahedral coordination is suggested for the complex acetylacetonato(2-acetylpyridine-benzoylhydrazonato)-oxovanadium(IV) (1), for which good agreement was verified between calculated and observed i.r. data. Two crystal structure modifications of (2-acetylpyridine-benzoylhydrazonato)dioxovanadium(V) (2) have been determined by X-ray diffraction methods. In both crystalline modifications the molecular structure of the complex shows a distorted trigonal bipyramidal VN₂O₃ coordination. The molecular structure, found experimentally for (2), was compared with the theoretically calculated one. The results validate the theoretical method.     

锌银双金属硫氰酸根络合物ZnAg_2(SCN)_4的晶体结构

本文报导了双金属硫氰酸根络合物ZnAg_2(SCN)_4的晶体结构。晶体属单斜晶系,空间群为Cc,晶胞参数:a=19.720(6),b=7.712(2),c=7.813(1);β=96。50°(2)°。每个晶胞含4个ZnAg_2(SCN)_(40)在CAD-4四圆衍射仪上用MoKα射线收集了I≥2σ(I)的971个独立衍射数据。晶体结构采用重原子法解出,用三维付立叶合成及全矩阵最小二乘法修正,偏离因子R为0.062。 在这一个结构冲,硫氰酸根作为三配位“桥”基,以其N端和Zn络合,以其S端同时与两个Ag络合,通过共价配键将整个结构联成三维的无穷骨架。Zn和Ag原子的邻近原子呈畸变的四面体配位构型。     

Copper(ii) halogenopropionates: low-temperature crystal and molecular structure of bis(2,2-dichloropropionato)-di(methyl-3-pyridylcarbamate)copper(ii) and bis(2-bromopropionato)-di (2-pyridylmethanol)copper(ii)

The synthesis and characterization of [Cu(CH₃CCl₂CO₂)₂(3-mpyc)₂] (1) (3-mpyc?=?methyl-3-pyridylcarbamate) and [Cu(CH₃CHBrCO₂)₂(2-pyme)₂] (2) (2-pyme?=?2-pyridylmethanol) are reported. The compounds under study were characterized by IR, electronic spectroscopy and X-ray analysis. The molecular structure of both Complexes 1 and 2 is mononuclear. The coordination environment around each copper(II) atom is a distorted tetragonal bipyramid.     

Bis(tetraphenylcyclobutadien)palladium(0)

Tetraphenylcyclobutadienepalladium dichloride reacts with 1,2,3,4-tetraphenyl-1,4-dilithiumbutadiene or with sodium with abstraction of halide to give the sandwich compound bis(tetraphenylcyclobutadiene)palladium(0). The structure of the latter is elucidated by spectroscopic methods and its reactions with Br₂, H₂, K and HNO₃ are described.     

Studies on Binuclear Co(II) and Cu(II) Complexes of Tridentate N-(2-Carboxyphenyl)Salicylideneimine

Homo Cu(II) and Co(II) binuclear complexes H[MLClMCl₂] formed by using the donor properties of the cis two oxygen atoms of the tridentate N-(2-carboxyphenyl)-salicylaldimine Schiff base derived from salicylaldehyde and anthranilic acid have been synthesized. It was found that the Cu(II) “complexed ligand” readily reacts with CoCl₂ to form mononuclear Co(II) and binuclear oxygen bridged Co(II) complex [Co₂-L₂](H₂O)₂. The structure of the so prepared complexes was investigated using microchemical analysis, molar conductance measurements as well as electronic and vibrational spectral studies. It was concluded that in the Cu(II) binuclear complex, the Cu(II) ion inside the “complexed ligand” has a planar structure while the other Cu(II) ion is distorted away from planarity. In the Co(II) binuclear complex, the Co atom of the “complexed ligand” is distorted from tetrahedral structure when it coordinates to the second Co atom.     

CsR(R(6)CoI(12))2 (R = Gd, Er) and (CeI)0.26(Ce(6)MnI(9))2: two new structure types featuring R(6)Z clusters

Compounds adopting two new structure types containing discrete lanthanide clusters have been found, CsR(R6CoI12)2 (R = Gd or Er) and (CeI)0.26(Ce6MnI9)2. CsEr(Er6CoI12)2 and CsGd(Gd6CoI12)2 were synthesized in reactions of CsI, RI3, CoI2, and R metals (3:19:6:23) heated to 750 degrees C for 500 h followed by slow cooling (0.1 degrees C/min). The X-ray crystal structure of CsEr(Er6CoI12)2 was solved in the Pa3 space group with a = 18.063(2) A at 250 K (Z = 4, R1 [I > 2sigma(I)] = 0.0459). (CeI)0.26(Ce6MnI9) was synthesized by combining KI, CeI3, MnI2, and Ce metal and heating to 850 degrees C for 500 h. The single-crystal X-ray structure for (CeI)0.26(Ce6MnI9)2 was solved in the trigonal, P3 (147) space group with lattice parameters of a = 11.695(1) A and c = 10.8591(2) A (Z = 2, R1 [I > 2sigma(I)] = 0.0895). Elemental analyses (X-ray photoelectron spectroscopy (XPS) and atomic absorption spectroscopy (AAS)) were performed and show the absence of potassium in the structure. A disorder model was refined for the atoms in the large cavity. The magnetic susceptibility data for CsGd(Gd6CoI12)2 is consistent with strong intracluster ferromagnetic coupling, but intercluster antiferromagnetic coupling suppresses the susceptibility below 70 K.     

Structure of 1-(arylselanyl)naphthalenes. 2. G dependence in 8-G-1-(p-YC(6)H(4)Se)C(10)H(6).

The structures of 8-G-1-(p-YC(6)H(4)Se)C(10)H(6) (1 (G = Cl) and 2 (G = Br): Y = H (a), OMe (b), Me (c), Cl (d), Br (e), COOEt (f), and NO(2) (g)) were investigated by X-ray crystallographic analysis, NMR spectroscopy, and ab initio MO calculations. The structures of all members in 1 and 2 are concluded to be type B, which is in striking contrast to the type A structure for 4d-g (4 (g(n)), where G = H). The Se-C(i) bond of the p-YC(6)H(4)Se group in 8-G-1-(p-YC(6)H(4)Se)C(10)H(6) is almost perpendicular to the naphthyl plane in type A, and it is located on the plane in type B. The chlorine and bromine substitution at the 8-position in 1 and 2 dramatically changes the type A structure of 4 (g(n)) to type B. The nonbonded G- - -Se-C 3c-4e type interaction must contribute to stabilize the type B structure. The type B structure in 1 and 2 should also be more stabilized than the same structure in 4 by the 3c-4e type interaction: The structure of 4b is type B in the crystals and type B would be more stable for 4c and might be for 4a in solutions. Ab initio MO calculations are performed on 8-G-1-(p-YC(6)H(4)Se)C(10)H(6), 8-G-C(10)H(6)SeH-1, and models HG- - -SeH(2), where G = Cl, Br, and F, to clarify the reason for the dramatic change in the structures. The type B structure is optimized to be more stable than the type A for all species examined, which supports the observations. The energy differences between type B and type A are larger for the models than for the naphthalenes. While the superiority of the type B for the former is Br > Cl > F, that of the latter is Br approximately Cl >/= F. These results show that the main factor of the structural change from type A to type B is the nonbonded G- - -Se-C 3c-4e interaction. The electronic effect of halogens through the naphthalene pi-framework would also contribute to some extent, although the direct comparison of the evaluated values between the naphthalene systems and the models is not so easy. Factors to stabilize the two structures of 1, 2, 4, and 8-(MeSe)-1-(p-YC(6)H(4)Se)C(10)H(6) are reexamined from a viewpoint of the nonbonded G- - -Se-C 3c-4e interaction (G dependence), together with the electronic effect of Y (Y dependence).     

Synthesis and Crystal Structure of Dichlorobis(dimethylsulfoxide)oxoperoxo Molybdenum(VI)

Hydrogen peroxide reacts with [MoO₂Cl₂(dmso)₂] to produce orange crystals of the title complex, [MoO(O₂)Cl₂(dmso)₂]. The structure is orthorhombic with distorted pentagonal bipyramidal geometry around the molybdenum ion. A short O‐O bond length suggested the presence of a superoxide, but electron paramagnetic resonance measurements definitely supported the peroxo structure.     

Mixed valence in YBaFe(2)O(5)

YBaFe(2)O(5) has been synthesized by heating a nanoscale citrate precursor in a carefully controlled reducing environment. Successful synthesis of a single-phase sample can only be achieved in a narrow window of oxygen partial pressures and temperatures. YBaFe(2)O(5) adopts an oxygen-deficient perovskite-type structure, which contains double layers of corner sharing FeO(5) square pyramids separated by Y(3+) ions. At T(N) congruent with 430 K, tetragonal (P4/mmm) and paramagnetic YBaFe(2)O(5) orders antiferromagnetically (AFM) experiencing a slight orthorhombic distortion (Pmmm). Around this temperature, it can be characterized as a class-III mixed valence (MV) compound, where all iron atoms exist as equivalent MV Fe(2.5+) ions. The magnetic structure is characterized by AFM Fe-O-Fe superexchange coupling within the double layers and a ferromagnetic Fe-Fe direct-exchange coupling between neighboring double layers. Upon cooling below approximately 335 K, a premonitory charge ordering (2Fe(2.5+) --> Fe(2.5+delta) + Fe(2.5)(-delta)) into a class-II MV phase takes place. This transition is detected by differential scanning calorimetry, but powder diffraction techniques fail to detect any volume change or a long-range structural order. At approximately 308 K, a complete charge ordering (2Fe(2.5+) --> Fe(2+) + Fe(3+)) into a class-I MV compound takes place. This charge localization triggers a number of changes in the crystal, magnetic, and electronic structure of YBaFe(2)O(5). The magnetic structure rearranges to a G-type AFM structure, where both the Fe-O-Fe superexchange and the Fe-Fe direct-exchange couplings are antiferromagnetic. The crystal structure rearranges (Pmma) to accommodate alternating chains of Fe(2+) and Fe(3+) running along b and an unexpectedly large cooperative Jahn-Teller distortion about the high-spin Fe(2+) ions. This order of charges does not fulfill the Anderson condition, and it rather corresponds to an ordering of doubly occupied Fe(2+) d(xz) orbitals. Comparisons with YBaMn(2)O(5) and YBaCo(2)O(5) are made to highlight the impact of changing the d-electron count.