Crystal structure of aqua[S-prolinato-N-monoacetato)copper(II) dihydrate [Cu(Proma)H2O] ⋅ 2H2O

The crystal structure of [Cu(C₇H₉NO₄)H₂O] ? 2H₂O is determined by X-ray diffraction (λMo, R = 0.0316 for 857 reflections). The crystals are tetragonal, a = 8.219(1) Å, c = 17.449(3) Å, Z = 4, ρ_calcd = 1.627 g cm^?3, and space group P4₃. The coordination polyhedron of the Cu atom is a tetragonal pyramid with the O atom of the acetate arm of the prolinatomonoacetate ion (Proma) in the apical position [Cu-O 2.312(6) Å]. The O atom of the water molecule and the N and O atoms of the prolinate group of the Proma ligand lie in the basal plane. The Cu-N bond length is 2.044(6) Å, and the Cu-O bond lengths are 1.932(7) and 1.927(6) Å. The O atom of the acetate arm of the neighboring Proma ion completes the basal plane [Cu-O 1.951(6) Å], thus linking the copper complexes into infinite chains.     

Crystal structure of triaquamaleatostrontium(II) monohydrate, [Sr(C4H2O4)(OH2)3]·H2O

[Sr(C₄H₂O₄)(OH₂)₃]·H₂O is monoclinic, P2₁/n, witha=11.476(2),b=7.027(1),c=12.344(2) Å, =115.74(3)°,V=896.67 ų,Z=4. The Sr atom is surrounded by nine oxygen atoms which come from four different maleate anions and three water molecules. The Sr–O distances range from 2.546(2) to 2.808(2) Å. The C–O distances are equal within the standard deviation 1.263(3) to 1.258(3) Å). In the maleate anion, the planes that contain the carboxylate groups form an angle of 74.44(9)°. Both carboxylate groups deviate significantly from planarity. The different coordination modes of the carboxylate group and the extensive hydrogen bonding present are responsible for the polymeric nature of the structure.     

Crystal structures of strontium and barium ethylenediaminetetraacetato cobaltates(III), Sr[CoEdta]2·9H2O and Ba[CoEdta]2·8H2O: Comparison of the structures of complexes in the series M’[CoEdta]2·nH2O (M’ = Mg, Ca, Sr, Ba; n = 7–10)

Cobalt(III) complexes, namely, Sr[CoEdta]₂·9H₂O (I) and Ba[CoEdta]₂·8H₂O (II) (where Edta ^4- is the ethylenediaminetetraacetate ion), are synthesized. The crystal structures of these compounds are determined using X-ray diffraction. Crystals of compound I are triclinic, a = 6.514(1) Å, b = 11.410(2) Å, c = 12.317(2) Å, α = 67.87(1)°, β = 88.73(2)°, γ = 84.22(2)°, V = 843.63(3) ų, Z = 1, space group P1, and R = 0.0295 for 4130 reflections with I > 2σ(I). Crystals of compound II are monoclinic, a = 6.543(2) Å, b = 12.895(3) Å, c = 19.489(4) Å, β = 95.24(3)°, V = 1637.5(5) ų, Z = 2, space group P2₁, and R = 0.050 for 3016 reflections with |F| > 3σ(|F|). The structures of compounds I and II are compared with those of the previously studied complexes Mg[CoEdta]₂·10H₂O (III) and Ca[CoEdta]₂·7H₂O (IV). The crystal structure of the cobalt(III) complex with the strontium cation (I) is topologically similar to the crystal structure of cobalt(III) complex with the calcium cation (IV). The former structure is built up of the two symmetrically independent homochiral anionic complexes [CoEdta]^? (A _I and B _I), the aqua cations [Sr(H₂O)₈]²⁺, and the molecules of crystalization water w _cr. The structure of compound II involves two independent anions [CoEdta]^? (A _II and B _II) with different chiralities (i.e., they are kryptoracemates). The A _II anions are linked via the barium cations into {Ba(H₂O)₇[CoEdta]} _1∞ ⁺ chain agglomerates due to the incorporation of two terminal oxygen atoms O_u of the anions neighboring in the chain into the coordination sphere of the barium atom. All four structures (I–IV) contain stacks composed of the [CoEdta]^? homochiral anions forming layers aligned parallel to the (001) plane. The aqua cations [Sr(H₂O)₈]²⁺, [Mg(H₂O)₆]²⁺, and [Ca(H₂O)₇]²⁺ or the partially hydrated barium cations [Ba(H₂O)₇(O_u)₂]²⁺ (in structure II), as well as water molecules w _cr, are located between the anion layers. The octahedral environment of the cobalt(III) atoms consists of donor atoms (2N and 4O) of the Edta ^4? ligand. The Co-N bonds in the A _I, B _I, A _II, and B _II anions [the mean bond lengths are 1.927(4), 1.921(4), 1.910(6), and 1.921(6) Å, respectively] are considerably longer than the Co-O bonds [the mean bond lengths are 1.908(5), 1.902(5), 1.904(6), and 1.908(6) Å, respectively]. The mean distances Sr-O_w and Ba-O_w in the strontium and barium polyhedra are 2.609(4) and 2.834(8) Å, respectively. The mean distance Ba-O_u is 2.814(7) Å.     

Crystal structures of acid ethylenediaminetetraacetates [Cd(H2 Edta)(H2O)] · 2H2O and [Mn(H2O)4][Mn(HEdta)(H2O)]2 · 4H2O

The crystal structures of [Cd(H₂ Edta)(H₂O)] · 2H₂O (I) and [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ · 4H₂O (II) are studied by X-ray diffraction [R ₁ = 0.0209 (0.0272), wR ₂ = 0.0571 (0.0730) for 2551 (4025) reflections with I > 2σ(I) in I (II), respectively]. Structure I contains mononuclear [Cd(H₂ Edta)(H₂O)] complexes with the C ₂ symmetry, and structure II contains centrosymmetric trinuclear [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ complexes. In I and II, the protonated ligands are hexadentate (2N + 4O), and the water molecule increases the coordination number of the metal atom to seven. The acid protons participate in short intermolecular hydrogen bonds, which are symmetric in II and asymmetric in I.     

Low temperature phases of strontium nitroprusside tetrahydrate (Sr[Fe(CN)5NO]·4H2O). Refinement of the neutron structure at 60 K

The behavior of Sr[Fe(CN)₅NO]·4H₂O between room temperature and 77 K has been investigated by X-ray powder diffraction (XRD), differential thermal analysis (DTA), and infrared spectroscopy (IRS). DTA puts into evidence five phase transitions—at 152.7, 174.3, 183.0, 193.0, and 199.5 K—when temperature is increased very slowly. When decreasing the temperature, XRD detects a change of space group below 153 K—from C2/m to P2/m—already reported as a result of a neutron diffraction study performed at 130 K. The P2/m space group remains at least down to 60 K. The structure at this temperature (monoclinic, space group P2/m, Z = 4, a = 19.765(21) Å, b = 7.540(5) Å, c = 8.384(1) Å, β = 98.87(1)°, V = 1236(16) ų) has been refined to a final R factor 0.077 using 687 observed structure factors. Of the two series of IR spectra obtained when cooling the sample (first series) and when heating the previously cooled sample (second series), only a feature of the first series of spectra seems to be related with the transition observed at 153 K.     

Synthesis and structure of (NH4)3[UO2(C3H2O4)2(NCS)] · 2H2O

Malonate-thiocyanate complex (NH₄)₃[UO₂(C₃H₂O₄)₂(NCS)] · 2H₂O is synthesized and studied by X-ray diffraction. The compound crystallizes in the monoclinic system: a = 13.9983(4) Å, b = 8.1947(2) Å, c = 16.4678(4) Å, β = 100.846(1)°, space group Cc, Z = 4, and R = 0.0158. The main structural units of the crystal are mononuclear [UO₂(C₃H₂O₄)₂(NCS)]^3? groups belonging to the AB ₂ ⁰¹ M ₁ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , B ⁰¹ = C₃H₂O ₄ ^2? , M ¹ = NCS^?). Discrete uranium-containing groups are connected by electrostatic interactions with ammonium ions and by hydrogen bonds. Some specific structural features of crystals containing [UO₂(L)₂(NCS)]^3? complexes, where L is the oxalate or malonate ion, are discussed.     

Crystal structure of calcium trans-N-(nitrilotriacetato)(pyridine-2-carboxylato)cobaltate(III) hexahydrate, Ca[Co(Nta)(Pic)]2] · 6H2O

Crystals of Ca[Co^III (Nta)(Pic)]₂ · 6H₂O (I) (where Nta ^3? and Pic ^? are the nitrilotriacetate and picolinate ions, respectively) are prepared and characterized by the X-ray diffraction technique. Crystals I are monoclinic, a = 18.599(4) Å, b = 12.556(3) Å, c = 14.042(3) Å, β = 102.90(3)°, V = 3196(1) ų, Z = 4, space group P2₁/c, R1 = 0.0278, wR2 = 0.0716, and Goof = 1.054 for 4982 reflections with I > 2σ(I). Structure I is built of the { Ca(H₂O)₄[Co(Nta)(Pic)]₂{ _1∞ polymer ribbons and molecules of crystallization water. One of the two symmetrically independent anionic complexes (B) is included in the chain and alternates with cationic units, whereas the other anionic complex (A) forms a branch of this chain. The cationic and anionic units are interlinked via the interactions of the Ca²⁺ cations with the carbonyl atoms of the main (Nta ^3?) and additional (Pic ^?1) ligands. The octahedral environment of the Co(III) atoms consists of donor atoms of the Nta ^3? (N + 3O) and Pic ^? (N + O) ligands. The coordination polyhedron of the Ca atom (pentagonal bipyramid) includes two carbonyl O atoms of two Nta ^3? ligands, one O_Pic atom, and four O_w atoms of water molecules.     

Crystal structure of {NH2C(NHC6H5)2}3[UO2(C2O4)2(NCS)] · 1.25H2O

Synthesis and X-ray diffraction study of {NH₂C(NHC₆H₅)₂}₃[UO₂(C₂O₄)₂(NCS)] · 1.25H₂O single crystals have been performed. This compound is crystallized in the orthorhombic system, with the unit-cell parameters a = 45.2646(8) Å, b = 57.7359(11) Å, c = 7.9244(3) Å, sp. gr. Fdd2, Z = 16, V = 20 709.6(10) ų, and R = 0.0477. The uranium-containing structural units of the crystals are one-core groups of the [UO₂(C₂O₄)₂(NCS)]^3? composition, belonging to the crystallochemical group AB ₂ ⁰¹ M ¹ (A = UO ₂ ⁺² , B ⁰¹ = C₂O ₄ ^2? , M ¹ = NCS^?) of uranyl complexes. The uranium-containing complexes are connected into a three-dimensional framework owing to the electrostatic interactions with the outer-sphere cations and a system of hydrogen bonds.     

Synthesis and crystal structure of hexaaquamagnesium hydrogen phosphododecatungstate tetrahydrate [Mg(H2O)6][HPW12O40]·4H2O

Crystals suitable for X-ray structure analysis were obtained after the slow evaporation of the reaction mixture containing equimolar quantities of magnesium chloride and dodecatungstophosphoric acid aqueous solution insuring pH of the solution between 1.0 and 1.2. This simple synthetic route yielded stability of Keggin anion and high quality [Mg(H₂O)₆][HPW₁₂O₄₀]·4H₂O single crystals. The obtained compound belongs to the group of heteropoly compounds and its structure is composed of Keggin [PW₁₂O₄₀]^3– anions, [Mg(H₂O)₆]²⁺ cations and lattice water molecules. Zigzag arrangement of Keggin anions along c-axis creates irregular channels occupied by [Mg(H₂O)₆]²⁺ cations and lattice H₂O molecules. The calculation of the total potential solvent volume indicated the presence of 4.1 lattice H₂O lattice molecules per formula unit, which is in agreement with the here presented structural model. The position of one lattice water molecule is well defined, while each of three other molecules is statistically distributed over two locations. Hydrogen bonds involve all coordinated and lattice H₂O molecules, as well as some oxygen atoms from the Keggin anion. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure of [Co(Ox)(NH3)4][Bi(Edta)] ⋅ 3H2O

The crystal structure of [Co(Ox)(NH₃)₄][Bi(Edta)] ? 3H₂O is determined. The crystals are monoclinic, a = 9.291 Å, b = 22.275 Å, c = 11.402 Å, β = 105.79°, V = 2270.7 ų, Z = 4, and space group P2₁/c. The [Bi(Edta)]^? anionic complexes are linked into polymeric chains through two Bi-O bonds with the neighboring complexes.     

Crystal and molecular structure of four copper(II) ethylenediaminedisuccinates, [Cu2(RR,SS-Edds)] · 6H2O, Ba2[Cu(RR,SS-Edds)](ClO4)2 · 8H2O, Ba[Cu(SS-HEdds)]ClO4 · 2H2O, and Ba3[Cu2(RR,SS-Edds)2](ClO4)2 · 6H2O

Four Cu(II) complexes with the RR,SS-Edds ^4? and SS-HEdds ^3? anions are synthesized, and their crystal structures are studied. In the compounds [Cu2(RR,SS-Edds)] · 6H₂O (I) and Ba2[Cu(RR,SS-Edds)](ClO₄)₂ · 8H₂O (II), the ligand forms hexacoordinate chelate [Cu(Edds)]^2? complexes with the N atoms and O atoms of the propionate groups in the equatorial positions and the O atoms of the acetate groups in the axial vertices. In the compounds Ba[Cu(SS-HEdds)]ClO₄ · 2H₂O (III) and Ba3[Cu2(RR,SS-Edds)₂](ClO₄)₂ · 6H₂O (IV), one of the propionate arms, the protonated arm in III and the deprotonated arm in IV, does not enter into the coordination sphere of the Cu atom. An acetate arm moves to its position in the equatorial plane, and the free axial vertex is occupied by an O atom of the perchlorate ion. In I–IV, the lengths of the equatorial Cu-N and Cu-O bonds fall in the ranges 1.970–2.014 and 1.921–1.970 Å, respectively. The axial Cu-O bonds with the acetate groups and ClO ₄ ^? anions are elongated to 2.293–2.500 and 2.727–2.992 Å, respectively. In structure I, the second Cu atom acts as a counterion forming bonds with the O atoms of two water molecules and three O atoms of the Edds ligands. In II–IV, the Ba²⁺ cations are hydrated and bound to the O atoms of the anionic complexes and (except for one of the cations in IV) ClO ₄ ^? anions. The coordination number of the Ba cations is nine. The structural units in I–IV are connected into layers. In I, an extended system of hydrogen bonds links the layers into a framework. In II and III, the layers are linked only by weak hydrogen bonds, one bond per structural unit. In IV, ClO ₄ ^? anions are bound to the Ba and Cu atoms of neighboring layers, thus serving as bridges between the layers.     

Crystal structure of a highly hydrated tristrontium phosphate,Sr9(PO4)6·16H2O

The crystal structure of a highly hydrated tristrontium phosphate, nonastrontium hexakis(phosphate) hexadecahydrate, Sr₉(PO₄)₆·16H₂O, has been determined by single crystal X-ray diffraction. The crystals are monoclinic,a=15.203(2),b=6.488(1),c=18.984(7) Å, =98.42(2)^o, space groupP2/c (No. 13),Z=2,V=1852.3 ų,d _c =2.951 Mg·m^–3. The structure was refined by full-matrix least-squares techniques toR=0.038,R _w =0.051, for 2329 reflections with I3(I). The structure can be described in terms of a layer-type arrangement parallel to (100). One layer consists of a compact assembly of columns of Sr and PO₄ ions in a pseudohexagonal arrangement resembling an apatitic structure. A second layer containing all the water molecules and one PO₄ ion that occupies the interstitial space may be referred to as the hydrated layer. The structure has an overall similarity to that of octacalcium phosphate and can be considered as a model for amorphous calcium phosphate.Certain commercial materials and equipment are identified in this paper to specify the experimental procedure. In no instance does such identification imply recommendation or endorsement by the National Institute of Standards and Technology or the ADA Health Foundation or that the material or equipment identified is necessarily the best available for the purpose.     

Crystal structure of Zn4Na(OH)6SO4Cl·6H2O

The structure of Zn₄Na(OH)₆SO₄Cl·6H₂O, a secondary mineral from Hettstedt, Germany, was determined by single-crystal X-ray diffraction. The crystals are hexagonal,a=8.413(8),c=13.095(24) Å, space group $P\bar 3$ , Z=2. The structure was refined to R=0.0554 and R_w=0.0903 for 970 reflections with I≥3σ(I). The structure can be described as zinc hydroxide layers perpendicular toc, from which sulfates and chlorides extend. The layers are held together by a system of hydrogen bonds involving hexaaquo Na⁺ ions which occupy the interlayer space.     

Molecular structure of [trans-FeCl2(imidazole)4]Cl·THF·H2O

The structure of [trans-FeCl₂(imidazole)₄]Cl has been determined as the THF/H₂O solvate. The Fe-Cl and Fe-N distances in the cation are shorter than analogous trans-FeCl₂(L)₄ compounds, concomitant with the decreased ionic radius of Fe³⁺ versus Fe²⁺. Crystal data: orthorhombic, Pnma, a = 8.456(2), b = 20.991(4), c = 13.288(3) Å, V = 2358.6(8), andZ = 4.     

Crystal and molecular structure of dipotassium-aquapentachlororhodate (III): (K2)++ [RhCl5(H2O)]2−

The structure of K₂[RhCl₅(H₂O)] has been established by X-ray crystallography. It crystallizes in the orthorhombic space groupPcmn, with cell dimensionsa=7.065(1),b=9.453(1),c=13.567(1) Å,V=906.1(3) ų,Z=4,M _r =376.4,D _x =2.76 g cm^–3,F(000)=712,T=293 K. The final wasR=0.046. The rhodium atom has a distorted octahedral coordination involving five chlorine atoms and an oxygen of the water molecule with Rh, O, and three chlorine atoms on the mirror plane. Rh-Cl distances range from 2.284(7) Å to 2.345(7) Å. The Cl(4)O intermolecular distance, 3.140(12) Å indicates strong hydrogen bonding between oxygen and chlorine atoms of the neighboring octahedra.N. C. L. Communication No. 5353.     

Synthesis, crystal structure, and thermal analyses of triaqua-(1,10-phenanthroline-N,N′) succinatomanganese(II) dihydrate, [Mn(H2O)3(phen)(C4H4O4)]·2H2O

[Mn(H₂O)₃(phen)(C₄H₄O₄)]·2H₂O was obtained by reaction of freshly prepared MnCO₃, phen and succinic acid in CH₃OH/H₂O (1:1 v/v), and its crystal structure has been determined by single crystal X-ray diffraction methods. The title mixed ligand complex crystallizes in the triclinic space group with cell dimensions a = 7.590(1) Å, b = 9.324(1) Å, c = 13.917(1) Å, = 85.64(1)°, = 74.56(1)°, = 77.10(1)°, and D _calc = 1.584 g/cm³ for Z = 2. The crystal structure consists of the [Mn(H₂O)₃(phen)(C₄H₄O₄)] complex molecules and lattice H₂O molecules. The Mn atoms are each octahedrally coordinated by two N atoms of one phen ligand and four O atoms of three H₂O molecules and one succinato ligand with d(Mn—N) = 2.271 and 2.299 Å, and d(Mn—O) = 2.133–2.239 Å. Through intermolecular hydrogen bondings, the complex molecules are interlinked to form 2D layers, which are assembled by – stacking interactions into 3D framework with tunnels occupied by the lattice H₂O molecules. Thermal analyses showed that the title compound decomposes in two steps over the range 25–600°C upon heating in flowing Ar.     

Crystal structure of chloro[1-hydroxyethane-1,1-diphosphonato(3−)]ditin(II) monohydrate Sn2(HL)Cl · H2O

The synthesis and X-ray structure analysis of Sn₂(HL)Cl · H₂O, where HL ^3? is the anion of 1-hydroxyethane-1,1-diphosphonic acid, are reported. The coordination polyhedra of two independent tin(II) atoms are the Sn(1)O₂Cl and Sn(2)O₃ trigonal pyramids, in which one of the vertices is occupied by a lone electron pair (Sn-O, 2.144–2.218 Å and Sn-Cl, 2.573 Å). The pyramids are complemented by weaker Sn?O and Sn?Cl contacts to form severely distorted (3 + 3) octahedra. The SnO₂Cl and SnO₃ pyramids are linked by the HL ^3? bridging ligands into the [Sn₂(HL)Cl]₆ cyclic molecules, which, in turn, are joined by additional Sn?O, Sn?Cl, O(H₂O)?O(L), and O(H₂O)?Cl contacts with each other and with crystallization water molecules into a three-dimensional framework.     

Crystal structure of [Co(bipy)(maleato) (H2O)3]·H2O (bipy = 2,2′-bipyridine)

Preparation of the mononuclear cobalt(II) complex, [Co(bipy)(maleato) (H₂O)₃]·H₂O (1) where bipy = 2,2-bipyridine, were accomplished by reaction of an aqueous solution containing sodium maleate and an ethanolic solution of Co(NO₃)₂·6H₂O and bipy. The crystal structure of complex (1) was determined by X-ray crystallography. The complex crystallizes in the monoclinic space group P2₁/n with a = 9.477(3), b = 7.660(2), c =23.526 (3) Å, = 97.64(2)°, V = 1692.6(6) ų, and Z = 4. The structure consists of discrete mononuclear cobalt molecules. The cobalt atom is six-coordinate and presents a slightly distorted octahedral geometry, which consists of the two imine N atoms of bipy, a terminal carboxylate O atom from maleato ligand, and a water O atom in the basal plane with Co—N bond distances of 2.116(2) and 2.124(3) Å and Co—O distances of 2.075(2) and 2.088(2) Å, respectively. The relatively shorter Co—O distances are due to the trans effect of the bipy ligand. The octahedral coordination is completed the other two water molecules. The coordinate and the lattice water molecules were identified by TG study.     

Crystal structure of catena-poly[diaqua(μ-iminodiacetato-N,O,O′: O″)cobalt(II)]

The crystal structure of the [Co(C₄H₅NO₄)(H₂O)₂] complex has been determined by X-ray diffraction analysis (λMo, R = 0.0237 for 768 reflections). The crystals are orthorhombic, a = 14.345(1) Å, b = 5.234(1) Å, c = 9.780(1) Å, Z = 4, d _calcd = 2.045 g cm^?3, and space group Pca2₁. The donor atoms (one N and two O atoms) of the iminodiacetate ion (Ida) are located on the same octahedron face around the Co atom [Co-N, 2.120(3) Å; Co-O, 2.063(3) and 2.151(3) Å]. The O atoms of two water molecules are in the trans positions relative to the O atoms of the carboxylate groups [Co-O, 2.126(3) and 2.157(3) Å]. The sixth coordination site is occupied by the O atom of the adjacent Ida ion [Co-O, 2.054(3) Å], which results in the formation of infinite chains in the structure.     

Crystal structure of calcium (Ornithinato-N (α), N (δ), N (δ )-triacetato)cobaltate(III) octahydrate Ca[Co(Orntra)]2 ⋅ 8H2O

The X-ray crystal structure of calcium (ornithinato-N _(α) N _(δ) N _{(δ )}-triacetato)cobaltate(III) octahydrate Ca[Co(Orntra)]₂ ? 8H₂O has been determined. The crystals are orthorhombic, a = 21.163(4) Å, b = 8.391(2) Å, c = 19.101(4) Å, V = 3391.9(9) ų, Z = 4, and space group Pca2₁. In the trinuclear linear molecule [Co(μ-Orntra)]₂Ca(H₂O)₅, two independent anions [Co(Orntra)]^? are joined with the Ca²⁺ cation by the bridging bonds through the terminal O atoms. In each [Co(Orntra)]^? anion, the Co atom occurs in the octahedral environment of two N atoms and four O atoms of the Orntra ligand and closes four five-membered and one seven-membered chelate rings. Two O atoms of two anions occupy axial vertices in a pentagonal bipyramid of the Ca²⁺ ion. Five O(H₂O) atoms are located in the equatorial plane. The asymmetric C atoms in the anions bound to the same Ca²⁺ cation have an identical absolute configuration. The crystal involves the molecules belonging to both configurations. The coordinated and outer-sphere H₂O molecules participate in an extended system of hydrogen bonds.