Crystal structure of 1:1 Complexes between urea and two crown ether derivatives of phthalic acid, 2,3,5,6,8,9,11,12,14,15-decahydrobenzo[1,4,7,10,13,16]hexaoxacyclo-octadecin-18,19-dicarboxylic acid (i) and 2,3,5,6,8,9,11,12-octahydro-benzo[1,4,7,10,13]pentaoxacyclopentadecin-15,16-dicarboxylic acid (II)

The crystal structures of the titlke compounds have been determined by X-ray diffraction. Urea, I crystallizes in the triclinic PI space group with cell dimensions a = 8.336(2), b = 11.009(2), c = 13.313(2) Å, α = 105.55(3), β = 103.62(3), γ = 104.63(3)° and Z = 2 final R value 0.072 for 2105 observations. Urea, II crystallizes in the orthorhombic P2₁2₁2₁ space group with cell dimensions a = 8.750(2), b = 10.844(3) and c = 21.215(3) Å and Z = 4, final R value 0.083 for 599 observations. All the hydrogen atoms were located in the complex urea, I ; urea molecules form hydrogen bonded dimers about centers of symmetry, these dimers are sandwiched between macrocyclic rings forming one simple and one bifurcated hydrogen bond from the “endo” hydrogen atoms to the ether oxygen atoms. These units are held by hydrogen bonding between the urea molecules and carboxylic acids in two other units; these hydrogen bonds are cyclic involving eight atoms -(N-H(exo)…O(keto)-C-O-H…O(urea)-C)-. Only one carboxylic acid group per molecule takes part in these hydrogen bonds, the other forms a short, 2.490(7) Å, internal bond to the acceptor keto oxygen atom. N(H)…O bonds range from 2.930(7) to 3.206(7) Å, O(H)…O is 2.475(6) Å. In the complex urea, II each urea is hydrogen bonded to three different host molecules and vice versa; the urea “endo” hydrogen atoms bond to the ether oxygen atoms, while both “exo” hydrogen atoms take part in cyclic hydrogen bonds to carboxylic acids. There is not internal hydrogen bond. N(H)…O bonds range from 2.83 to 3.26(2) A and the O-…O bonds are 2.55 and 2.56(2) Å.     

Isolation and X-ray Structure of [Ir(CNBu t ) 5 H](PF 6 ) 2

Reaction of tert -butyl isocyanide with [Ir(COD)Cl] 2 and NH 4 PF 6 yields [Ir(CNBu t ) 5 H](PF 6 ) 2 ( 1 ). The hydride ligand is observed by both proton NMR and infrared spectroscopy. Complex 1 is triclinic, P-1, a = 11.307(3), b = 14.619(3), c = 15.486(3) Å, f = 98.204(3), g = 106.851(3), n = 106.953(3)°, Z = 2, 6746 reflections [I S 2 σ (I)], R1 = 0.0397, w R 2 = 0.0984. The closest Ir-Ir interatomic distance within the crystal is 8.6 Å. EPR and cyclic voltammetry studies also support the identity of 1 .     

混合三烃基锡有机酸酯化合物构效关系 （Ⅰ）二环己基－甲基－2，4－二溴－β－甲基苯氧乙酸锡酯 及二环己基－甲基－2－甲氧基－4－丙烯基苯氧乙酸锡酯的晶体结构和分子结构

报道２，４－Ｂｒ２Ｃ６Ｈ３ＯＣＨ（ＣＮ３）ＣＯ２Ｓｎ（Ｃ６Ｈ１１）２ＣＵ３（１）和２－ＯＣＨ３－４－ＣＨ３ＣＨ＝ＣＨＣ６Ｈ３ＯＣＨ２ＣＯ２Ｓｎ（Ｃ６Ｈ１１）２ＣＨ３（Ｈ２Ｏ）（Ⅱ）的晶体结构和分子结构。（Ⅰ）单斜晶系，空间群Ｐ２１／ｃ，ａ＝１３．０６７（３），ｂ＝１０．５９４（３），ｃ＝１８．１５７（４），β＝１０６．９９（２）°，Ｚ＝４，Ｄｃ＝１．６７２ｇ／ｃｍ３，Ｖ＝２４０３．７３，μ＝４３．７３１ｃｍ－１，Ｍｒ＝６２２．９９，Ｆ（０００）＝１２３２；（Ⅱ）单斜晶系，空间群Ｐ２１／ｎ，ａ＝１０．４０９（１），ｂ＝　１２．５７０（２），ｃ＝２０．６６４（２），β＝８３．５１（１）°，Ｚ＝４，Ｄｃ＝１．２８１ｇ／ｃｍ３，Ｖ＝２６８６．４Ａ３，μ＝９．７６１ｃｍ－１，Ｍｒ＝５３９．２８，Ｆ（０００）＝１１２０．最后的偏离因子，化合物（Ⅰ）Ｒ＝０．０４６，Ｒω＝０．０４６；化合物（Ⅱ）Ｒ＝０．０４９，Ｒω＝０．０４７。晶体结构解析表明，化合物（Ⅰ）和（Ⅱ）中的锡均被配体的３个碳和２个氧原子配位，配位原子呈畸变三角双锥构型；化合物中的环己基均为椅式构象；化合物（Ⅱ）中，配位水分子和另一分子的羰基氧与芳环上的甲基氧?     

Zur Darstellung und Kristallstruktur von CrSO4 · 3 H2O

Preparation and Crystal Structure of CrSO₄ · 3 H₂O Evaporating a solution of Cr²⁺ in dilute sulphuric acid at 70°C light blue crystals of CrSO₄ · 3 H₂O were grown. Its x-ray powder diffraction pattern is quite similar to that of CuSO₄ · 3 H₂O. The crystal structure refinement of CrSO₄ · 3 H₂O (space group Ce, a = 5.7056(8) Å, b = 13.211(2) Å, c = 7.485(1) Å, β = 96.73(1)°, Z = 4) from single crystal data, using the parameters of the copper compound as starting values, results in a final R-value of R = 3.8%. The surrounding of the Cr²⁺ ion can be described as a strongly elongated octahedron. The basal plane of the CrO₆-octahedron consists of three hydrate oxygen atoms and one sulphate oxygen atom. The two more distant axial oxygen atoms also belong to sulphate groups. Thus they are forming chains of alterning CrO₆-octahedra and SO₄-tetrahedra along [110] and [1–10] linked via common corners. These chains are connected via sulphate groups and by bridging hydrogen bonds to a 3-dimensional network.     

A new binuclear germanium(IV) and copper(II) complex with 1,3-diamino-2-propanoltetraacetic acid: Crystal and molecular structure of [(H2O)(OH)Ge(μ-Hpdta)Cu(H2O)] · 3H2O

A heteronuclear germanium(IV) and copper(II) complex with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) has been synthesized for the first time. The compound has been characterized by elemental analysis, X-ray diffraction, thermogravimetry, and IR spectroscopy. The structure of the complex [(H₂O)(OH)Ge(μ-Hpdta)Cu(H₂O)] · 3H₂O (I) has been determined by single-crystal X-ray diffraction. The crystals of I are monoclinic, a = 1 5.327(4) Å, b = 11.626(3) Å, c =21.058(3) Å, β = 96.35(2)°, V = 3729.2(2) ų, Z = 8, space group C2/c, R1 = 0.0551 on 3090 reflections with I > 2σ(I). The structural units of the crystal of I are binuclear complex molecules [(H₂O)(OH)Ge(μ-Hpdta)Cu(H₂O)] and crystal water molecules. The germanium and copper atoms are linked by the bridging oxygen atom of the deprotonated isopropanol group of the Hpdta^5? ligand (Ge-O, 1.843(3) Å; Cu-O, 2.221(3) Å). The coordination spheres of the Ge and Cu atoms contain each one nitrogen atom (Ge-N, 2.090(4) Å; Cu-N, 2.000(4) Å) and two carboxyl oxygen atoms from four acetate arms of the heptadentate Hpdta^5? ligand (av. Ge-O, 1.909(3) Å; Cu-O, 1.948(3) Å). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atoms of the terminal hydroxy group (Ge-O, 1.786(3) Å) and a water molecule (Ge-O, 1.904(3)Å). The coordination polyhedron of the copper atom is completed to a prolate tetragonal pyramid (4 + 1) by the oxygen atom of a water molecule in the equatorial position (Cu-O, 1.955(4) Å) and the bridging O(11) atom (Hpdta^5?) in the apical position. Binuclear molecules are linked pairwise in a head-to-head manner via double Cu-O(2) bridges to form the centrosymmetric tetranuclear supramolecule {[(H₂O)(OH)Ge(μ-Hpdta)Cu(H₂O)]}₂. The coordination of the Cu atom is completed by the weak Cu-O(2A) contact (3.303 Å) to an asymmetrically elongated tetragonal bipyramid (4 + 1 +1). In the crystal, the complex molecules and crystal water molecules are combined by a system of hydrogen bonds into a three-dimensional framework.     

Strukturuntersuchungen an den Oxidnitriden SrTaO2N,CaTaO2N und LaTaON2 mittels Neutronen‐ und Röntgenbeugung

Structural Investigations on the Oxidenitrides SrTaO₂N, CaTaO₂N and LaTaON₂ by Neutron and X‐ray Powder Diffraction The crystal structures of the perovskite related oxidenitrides SrTaO₂N, LaTaON₂ and CaTaO₂N have been determined with special regard to the structures of the respective anionic partial structure. The structure refinements were performed by individual Rietveld analyses of both X‐ray and neutron powder diffractograms and in addition by joint refinements in order to confirm the results. Both refinement methods yield consistent structure solutions. At least the first two compounds have fully ordered anionic sublattices. The crystal structure of SrTaO₂N has been solved in the space group I4/mcm (a = 5.7049(3) Å, c = 8.0499(5) Å, R_p = 0.0706, R_wp = 0.0904, reflections: 70 (neutrons)/36 (X‐ray), R(F²)(n) = 0.147, R(F²)(X) = 0.0952), with an ordered anionic partial structure. LaTaON₂ crystallizes monoclinic (C2/m, a = 8.0922(3) Å, b = 8.0603(2) Å, c = 5.7118(2) Å, β = 134.815(1)°, R_p = 0.0592, R_wp = 0.0766, reflections: 235(n)/113(X), R(F²)(n) = 0.0944, R(F²)(X) = 0.165) and also shows a totally ordered distribution of the anions. In the case of CaTaO₂N (Pnma, a = 5.6239(3) Å, b = 7.8954(4) Å, c = 5.5473(3) Å, R_p = 0.0503, R_wp = 0.0656, reflections 206(n)/110(X), R(F²)(n) = 0.0985, R(F²)(X) = 0.0405) slightly unbalanced displacement parameters (neutron data, ordered O/N distribution model) hint at a partial exchange of oxygen and nitrogen.     

A new dinuclear molybdenum(V)-sulfur complex containing citrate ligand: Synthesis and characterization of K2.5Na2NH4[Mo2O2S2(cit)2].5H2O

The complex, K_2.5Na₂NH₄[Mo₂O₂S₂(cit)₂]·5H₂O (1), was obtained by crystallization from a solution of (NH₄)₂MoS₄, potassium citrate (K₃cit) and hydroxyl sodium in methanol and water under an atmosphere of pure nitrogen at ambient temperature. The crystals are triclinic, space group P1¯, a = 7.376 (3)Å, b = 14.620 (2) Å, c = 14.661 (1) Å, α = 71.10 (1)°, β = 81.77 (1)°, γ = 78.27(2)°, R = 0.0584 for 2545 observed (I > 2σ (I)) reflections. Single crystal structure analysis reveals that citrate ligand coordinated to molybdenum atom through two carboxylato oxygens and one deprotonated hydroxyl oxygen together with two bridging sulfur atoms and a terminal oxygen atom completes distorted coordination octahedron around each molybdenum atom. Principal dimensions are Mo = O₁, 1.707 Å (av); Mo-S_b, 2.341 Å (av); Mo-O_(hydroxyl), 2.021 Å (av); Mo-O_{(α-carboxyl)}, 2.1290 Å (av) and Mo-O_{(β-carboxyl)}, 2.268(av) Å. IR spectrum is in agreement with the structure.     

稀土氧化膦取代杯芳烃配合物的合成与结构

合成了一种新的氧化膦取代杯芳烃衍生物的稀土离子(La³⁺,Eu³⁺)硝酸盐配合物.通过元素分析和红外光谱对配合物进行了表征.在无水甲醇中培养出了配合物的单晶,用X射线单晶衍射法测定了其晶体结构.硝酸镧配合物晶体[L·La(OH₂)(NO₃)₂]NO₃{L为四(亚甲基二苯基氧化膦)杯[4]芳烃}属四方晶系,空间群P4₃2₁2,晶胞参数a=b=1.8977(4)nm,c=3.1087(11)nm;Z=4;V=11.196(5)nm³;D_c=1.097g/cm³,F(000)=3712,μ=0.491mm^-1,R₁=0.1181,wR₂=0.1930.硝酸铕配合物晶体[L·Eu(OH₂)(NO₃)₂]NO₃·CH₃OH属单斜晶系,空间群C2/c,晶胞参数a=2.88172(11)nm,b=5.4015(2)nm,c=2.01189(7)nm;β=133.4067(9)°,Z=8;V=22.7511(14)nm³,D_c=1.106g/cm³,F(000)=7464,R₁=0.0671,wR₂=0.1794.2个配合物的晶体结构相类似,配合物中配体的4个磷氧键上的氧原子、2个双齿配位的硝酸根中的4个氧原子还有1个水分子中的氧原子分别参与了配位.中心离子配位数为9,配位多面体为单帽四方反棱柱体.另外在铕配合物的杯芳烃中还包合了1个甲醇分子.     

Synthesis and X-Ray Crystal Structure of the TiMgCl6(CH3COOC2H5)4 Adduct

The molecular and crystal structure of TiMgCl₆(CH₃COOC₂H₅)₄, obtained by reacting TiCl₄ with a solution of MgCl₂ in dry CH₃COOC₂H₅, have been determined by x-ray diffraction. The structure was solved by direct and Fourier methods and refined by least-squares techniques to R = 0.052 for 2722 independent observed reflections. Unit-cell dimensions are a = 17.122(7), b = 9.833(3), c = 9.646(3) Å, α = 111.10(7)°, β = 107.22(6)°, γ = 103.11(6)° with Z = 2 for P1 . The titanium(IV) atom is octahedrally coordinated by six chlorine atoms (Ti? Cl_t = 2.293(2) Å, Ti? Cl_b = 2.480(2) Å) and magnesium by two chlorine atoms (Mg? Cl_b = 2.528(2) Å) and the carbonyl oxygen atoms of the four CH₃COOC₂H₅ residues (Mg? O = 2.038(5) Å). The octahedra share an edge by a double chlorine bridge between the magnesium and titanium atoms. Changes in the configurations and dimensions of the free acceptor and donor molecules on adduct formation are discussed. One of the ethylacetate residues shows positional disorder, eventually with Bonding through its ethereal oxygen.     

含氧桥的笼状化合物[Mo_5P_2O_(23)]~(6-)[(CH_3)_2NH_2]_5~(5+)-[H_3O]~+·1/2(CH_3)_2NCHo·1/2H_2O的合成和结构

[Mo_5P_2O_(23)]~(6-)[(CH_3)_2NH_2]_5~(5+)[H_3O]~+·1/2DMF·1/2H_2O(DMF=(CH_3)_2NC-HO)(M_r=1204.67)的晶体属三斜晶系,空间群P,晶胞参数a=16.438(6);b=22.22(1);c=11.325(5),α=104.25(4);β=108.97(3);γ=97.68(4)°,V=3688(3),Z=4,D_c=2.17gcm~(-1),R=0.056,R_w=0.074,晶胞中每个不对称单元含有两个[Mo_5P_2O_(23)]~(6-)[(CH_3)_2NH_2]_5~(5+)[H_3O]~+·1/2DMF·1/2H_2O,阴离子[Mo_5P_2O_(23)]~(6-)中的Mo、P原子成一个畸变五角双锥构型。有一个阴离子的所有原子(Mo、P、O)位置完全确定,而另一个阴离子有一个磷酸根的三个氧原子位置出现二重位置统计分布。化合物的阳离子为二甲胺阳离子和水合氢离子。     

Syntheses and X-Ray Crystal Structures of 2-Aminoindenes and Aminocymantrenes

Substituted 2-aminoindenes have been synthesized in almost quantitative yields by reactions of amines such as methylpiperazine, trimethylethylenediamine, 1,4-diaza-cycloheptane and N,N′-dimethylethylenediamine with 2-indanone. The 2-aminoindenes can be deprotonated and reacted with BrMn(CO)₃(Py)₂ to produce the respective aminoindenyl-cymantrenes in yields between 55–70%. The X-ray crystal structures of 2-(methylpiperazine)indenyl-cymantrene 5 (P1 , a = 12.667(3) Å, b = 16.630(3) Å, c = 17.382(3) Å, α = 72.70(3)°, β = 74.59(3)°, γ = 88.66(3)°, V = 3364.1(12) Å ³, Z = 8, R1(2σ(I)) = 4.02%, wR2(2σ(I)) = 10.30%) and the HClO₄ adduct of 2-(trimethylethylenediamine)-indenyl-cymantrene 6 (Cc, a = 23.722(5) Å, b = 6.9080 Å, c = 13.264 Å, β = 111.77(3)°, V = 2018.6(7) Å 3, Z = 4, R1(2σ(I)) = 2.94%, wR2(2σ(I)) = 7.90%) were determined. In both complexes the indenyl-carbon bonded to nitrogen displays significantly longer bonds to manganese [223.5(3)–225.8(3) pm] than the other four carbon atoms [213.3(3)–219.1(3) pm]. The short indenyl-nitrogen bonds of 136.2(4) and 137.8(4) pm are indicative of a substantial multiple bond character. The complexation of Zn²⁺ by the nitrogen atoms of 6 results in significant shifts of the CO stretching frequencies.     

A 2D Acentric Coordination Polymer, [Mn(HIDA)2(H2O)2], with a Strong Second‐Order Nonlinear Optical Effect

The crystal structure of [Mn(HIDA)₂(H₂O)₂] (Tetragonal, P4¯2₁c (no.114), a = b = 8.10(2)Å, c = 9.605(3)Å, α = β = γ = 90°, Z = 2, R = 0.051, wR² = 0.123 for 460 observed reflections) consists of infinite acentric 2D square grids with HIDA^— ions as bridging ligands. The 2D grids are interlocked(along the c axis) by hydrogen bonding. The Mn atoms are octahedrally coordinated by four O atoms of four HIDA^— ions (d(Mn—O)= 2.183(4)Å ) and two O atoms of two water molecules (d(Mn—OW) = 2.154(5)Å ). The results show that this acentric coordination polymer exhibits strong powder second harmonic generation (SHG) efficiency, ca. 1.9 times that of potassium dihydrogen phosphate, and remarkable thermal stability.     

Synthesis and crystal structure of divaleratobis(nicotinamide)copper(II)

A copper(II) valerate complex with nicotinamide (L) [CuL₂(C₄H₉COO)₂] (I) has been synthesized and studied by IR spectroscopy and thermogravimetry. The crystal structure has been determined. The crystals of 1 are monoclinic, a = 11.297(1) Å, b = 6.666(1) Å, c = 16.873(2) Å, b = 108.50(1)°, V = 1204.9(3) ų, Z = 2, space group P2₁/c. The structural units of the crystal of I are centrosymmetric tetragonal bipyramidal (4+2) complex molecules. The equatorial positions of the bipyramid are occupied by trans-arranged pairs of O (Cu-O, 1.973 Å) and N (Cu-N, 2.006 Å) atoms, and the axial positions are occupied by the second O atoms of the valerate anions located at longer distances (Cu-O, 2.506 Å). The supramolecular associates formed in the crystal are layers of hydrogen-bonded complexes. The disordered hydrocarbon “tails” of the valerate groups point toward the interlayer space.     

Mobybdenum(VI)-oxygen complex containing citrage ligand: synthesis and characterization of K6[Mo2O5(cit)2]·5H2O

The complex, K₆[Mo₂O₅(cit)₂]·5H₂O was obtained by crystallization from reaction of [Et₄N]₃[Mo₂FeS₈O₂ and potassium citrate (K₃cit) in methanol and water under an atmosphere of pure nitrogen at ambient temperature. The complex is triclinic, space group P1, a = 11.843(8) Å, b = 13.717(8) Å, c = 10.287(5) Å, α = 108.11(4) °, β = 99.42(5) (1) °, γ = 66.52(4) °, R = 0.034 for 4510 observed (I > 3 σ (I)) reflections. Single crystal structure analysis reveals that citrate ligand coordinated to molybdenum atom through two carboxylato oxygens and one deprotonated hydroxyl oxygen together with one bridging oxygen atom and two terminal oxygen atoms completes distorted coordination octahedron around each molybdenum atom. IR spectra are in agreement with the structure.     

Crystal and molecular structure of methyl 2-bis(pentyloxy)phosphoryl-2-phenylsulfonamido-3,3,3-trifluoropropionate

Crystal and molecular structure of methyl 2-bis(pentyloxy)phosphoryl-2-phenylsulfonamido-3,3,3-trifluoropropionate (I) was determined by XRD analysis: space group $P\bar 1$ , a=9.406(3), b=12.068(6), c=14.150(8) Å, α=66.88(5), β=68.61(5), γ=71.33(5)°, Z=2, R=0.090 (CAD-4 automatic diffractometer, λCuK_α, 1950 independent reflections with I≥2σ). The S and P atoms of molecule I have a distorted tetrahedral coordination. The S?N?C?P torsion angle is 159.4°. The two pentyl substituents in structure I have different conformations, and their atoms make rather intense thermal vibrations. In crystal structure I, the molecules are linked into centrosymmetric H-dimers by pairs of intermolecular hydrogen bonds N?H...O=P.     

Synthesis, Structure and IR Spectrum of Octanuclear Mixed-metal Cluster Compound Na_2[CrW_3O_4(O_2CCH_3)_8]_2· H_2O

lIRTRoDUCTIoNClusterswithcarboxylateligandsthatcontainVIBmetalshavebeenextensivelystudiedformanyyears,agreatmotivationisthepotentialapplicationinelectrrvmagneticmaterialandhomogeneouscatalystsforsomeorganicreactiOns.Todata,avari-etyofVIBmetalclusterswithcarboxylateligandshavebeensynthesizedandstructurallycharacterized.Recently,wereportedthesynthesis,X-raystructureandsPeC-trosc6piccharactersofaseriesofoctanuclearmixed-m9talclustercomPOundswithpropionateligands,whichcontaintrinuclear.[M…     

Über Chalkogenolate. 114. Kristallstruktur von Kalium-N-cyanodithiocarbimat-Monohydrat K2[S2CN ? CN] · H2O

On Chalcogenolates. 114. Crystal Structure of Potassium N-Cyanodithiocarbimate Monohydrate K₂[S₂C?N ? CN] · H₂O The crystal structure of the title compound has been determined and refined to R = 0.0287. K₂[S₂C?N ? CN] · H₂O crystallizes in the orthorhombic space group Pnma with a = 10.336(1) Å, b = 7.862(1) Å, c = 9.882(1) Å Z = 4. The structure is built up from layers of cations and anions. The potassium ion is coordinated by O, N, S atoms. The coordination polyhedron is a quadratic antiprism. ¹³C and ¹⁵N NMR data are reported and discussed.     

Crystal structure and triboluminescence of the [Eu(TTA)2(NO3)(TPPO)2] complex

The crystal structure of [Eu(TTA)₂(NO₃)(TPPO)₂] (I) (TTA = thenoyltrifluoroacetone, TPPO = triphenylphosphine oxide) possessing intense triboluminescence was established by X-ray crystallography. The crystals are triclinic, noncentrocymmetrical: a = 11.047(3) Å, b = 11.794(3) Å, c = 12.537(3) Å; α = 102.635 (4)°, β = 102.088(4)°,γ = 117.765(3)°; space group P1, Z = 1. The central Eu(III) atom coordinates two oxygen atoms of two TPPO molecules at distances of 2.271 Å and 2.282 Å, two oxygen atoms of the nitrate group at distances of 2.478 Å and 2.481 Å, four oxygen atoms of two TTA ions at distances of 2.365 Å, 2.381 Å, and 2.363 Å, 2.371 Å (coordination number is 8). The coordination polyhedron of the Eu(III) atom is a distorted dodecahedron. Possible reasons for spectral differences in the Stark structure of photo-and triboluminescence of I are discussed.     

Structural Investigations and Thermal Behavior of (NH4)[Cr(C2O4)2]·2H2O

Single crystals of ammonium chromium(III) dioxalate dihydrate (or ammonium diaquo bis(μ‐oxalato)chromate(III)) have been obtained from aqueous solution of oxalic acid and ammonium dichromate. A pale violet crystal of good optical quality was used for the structure determination at ?100(2) and 25(2) °C, respectively. The basic crystallographic data for the low temperature data set are as follows: monoclinic, space group C2/m, a = 6.597(2) Å, b = 7.301(2) Å, c = 9.983(3) Å, β = 92.32(2)°, V = 480.5(2) ų. The structure was solved by direct methods and refined (using anisotropic displacement parameters for all non‐hydrogen atoms) to a final residual of R1 = 0.032 for 503 independent observed reflections (I>2σ(I)). The compound is isotypic with the corresponding rubidium salt. The structure is built up from alternating layers parallel to (001) containing (NH₄)⁺ ions or Cr(C₂O₄)₂(H₂O)₂ octahedra, respectively. The corners of the octahedra consist of four O atoms from two oxalate groups and two additional water molecules. The ammonium cations (occupying Wyckoff‐site 2a) are disordered among two possible orientations. They provide linkage between different octahedral layers by hydrogen bridging. The water molecules in turn form hydrogen bridges with adjacent octahedra within the same layer. Further structural characterization included infrared spectroscopy. According to DTA/TG experiments the present compound shows several thermal processes in the range between room temperature and 900 °C.     

SYNTHESIS AND STRUCTURE OF THE PEROXOVANADIUM (V) COMPLEX CONTAINING NITRILOTRIACETATE Na_2[VO (O_2) N-(CH_2COO)_3]·5H_2O

<正> Na2[VO(O2)N(CH2COO)3] · 5H2O, Mr= 423. 11, monoclinic, space group P21/c, a = 6. 283(3), b = 20. 378(6), c=12. 056(4)(?) , β=102. 96 (3)°, V = 1507. 9(?)3, Z = 4, Dc= 1. 864 g/cm3. λ(MoKα) = 0. 71069A , F(000) = 864. Final R = 0. 037 and Rw = 0. 046 for 1658 observed reflections with I>10σ (I). The structure of the anion of the title complex shows that the vanadium atom is coordinated by one vanadyl oxygen atom, two oxygen atoms of the peroxp-group, three oxygen atoms and one nitrogen atom from the NTA ligand to form a distorted pentagonal bipyramid.