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O Distances (o + distance)

Distribution by Scientific Domains
Chemistry92%
Physics and Astronomy7%
Distribution within Chemistry
Crystallography83%
General & Introductory Chemistry7%
2 Other Subdomains10%

Selected Abstracts

Dinuclear Complexes of MII Thiocyanate (M = Ni and Cu) Containing a Tridentate Schiff-Base Ligand: Synthesis, Structural Diversity and Magnetic Properties

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2005
Suparna Banerjee
Abstract A dinuclear NiII complex, [Ni2(L)2(H2O)(NCS)2]·3H2O (1) in which the metal atoms are bridged by one water molecule and two ,2 -phenolate ions, and a thiocyanato-bridged dimeric CuII complex, [Cu(L)NCS]2 (2) [L = tridentate Schiff-base ligand, N -(3-aminopropyl)salicylaldimine, derived from 1:1 condensation of salicylaldehyde and 1,3-diaminopropane], have been synthesized and characterized by IR and UV/Vis spectroscopy, cyclic voltammetry and single-crystal X-ray diffraction studies. The structure of 1 consists of dinuclear units with crystallographic C2 symmetry in which each NiII atom is in a distorted octahedral environment. The Ni,O distance and the Ni,O,Ni angle, through the bridged water molecule, are 2.240(11) Å and 82.5(5)°, respectively. The structure of 2 consists of dinuclear units bridged asymmetrically by di-,1,3 -NCS ions; each CuII ion is in a square-pyramidal environment with , = 0.25. Variable-temperature magnetic susceptibility studies indicate the presence of dominant ferromagnetic exchange coupling in complex 1 with J = 3.1 cm,1, whereas complex 2 exhibits weak antiferromagnetic coupling between the CuII centers with J = ,1.7 cm,1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

XAFS and neutron diffraction study of the La1,xSrxCoO3

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007
V. Efimov
Abstract We have studied the effects of hole doping on the crystal and electronic structure of the La1,xSrxCoO3 (x = 0.0 ÷ 0.5) by neutron Rietveld analysis and its correlation with the X-ray-absorption spectroscopy data. The abrupt decrease of the Co,O distance and an increase of the Co,O,Co angle upon substitution of La3+ by Sr2+ in La1,xSrxCoO3 are attributed to a change in the band structure at the transition from semiconducting to metallic state. Upon strontium doping, a variation of Co L2,3 -edges in La1,xSrxCoO3 series suggests an increase of the mixed low Co4+ and high or intermediate Co3+ spin states. The possible explanation of the observed changes of the crystal and electronic structure in these cobaltites is discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

High-pressure neutron diffraction study of l -serine-I and l -serine-II, and the structure of l -serine-III at 8.1,GPa

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2006
Stephen A. Moggach
The hydrostatic compression of l -serine- d7 has been studied to 8.1,GPa by neutron powder diffraction. Over the course of this pressure range the compound undergoes two phase transitions, the first between 4.6 and 5.2,GPa, yielding l -serine-II, and the second between 7.3 and 8.1,GPa, yielding l -serine-III. All three polymorphs are orthorhombic, P212121, and feature chains of serine molecules connected via head-to-tail ND,O hydrogen bonds formed between ammonium and carboxylate groups. The chains are linked into a ribbon by a second set of ND,O hydrogen bonds. The hydroxyl moieties are distributed along the outer edges of the ribbon and in phase I they connect the ribbons into a layer by chains of OD,OD hydrogen bonds. The layers are connected together by a third set of ND,O hydrogen bonds, forming rings with substantial voids at their centres. In the transition from phase I to II these voids begin to close up, but at the cost of breaking the OD,OD chains. The OD,OD hydrogen bonds are replaced by shorter OD,O hydrogen bonds to carboxylate groups. At 7.3,GPa the O,O distance in the OD,O hydrogen bonds measures only 2.516,(17),Å, which is short, and we propose that the phase transition to phase III that occurs between 7.3 and 8.1,GPa relieves the strain that has built up in this region of the structure. The hydroxyl D atom now bifurcates between the OD,O contact that had been present in phase II and a new OD,O contact formed to a carboxylate in another layer. Hirshfeld surface fingerprint plots show that D,D interactions become more numerous, while hydrogen bonds actually begin to lengthen in the transition from phase II to III. [source]

3-Nitrophenol,4,4,-bipyridyl N,N,-dioxide (2/1): a DFT study and CSD analysis of DPNO molecular complexes

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010
Rodolfo Moreno-Fuquen
The title 2:1 complex of 3-nitrophenol (MNP) and 4,4,-bipyridyl N,N,-dioxide (DPNO), 2C6H5NO3·C10H8N2O2 or 2MNP·DPNO, crystallizes as a centrosymmetric three-component adduct with a dihedral angle of 59.40,(8)° between the planes of the benzene rings of MNP and DPNO (the DPNO moiety lies across a crystallographic inversion centre located at the mid-point of the C,C bond linking its aromatic rings). The complex owes its formation to O,H...O hydrogen bonds [O...O = 2.605,(3),Å]. Molecules are linked by intermolecular C,H...O and C,H...N interactions forming R21(6) and R22(10) rings, and R66(34) and R44(26) macro-rings, all of which are aligned along the [01] direction, and R22(10) and R21(7) rings aligned along the [010] direction. The combination of chains of rings along the [01] and [010] directions generates the three-dimensional structure. A total of 27 systems containing the DNPO molecule and forming molecular complexes of an organic nature were analysed and compared with the structural characteristics of the dioxide reported here. The N,O distance [1.325,(2),Å] depends not only on the interactions involving the O atom at the N,O group, but also on the structural ordering and additional three-dimensional interactions in the crystal structure. A density functional theory (DFT) optimized structure at the B3LYP/6-311G(d,p) level is compared with the molecular structure in the solid state. [source]

(3,8,9,14-Tetraethyl-2,4,13,15-tetramethyltripyrrinato)(trifluoroacetato)­palladium(II)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2007
Serguei Prikhodovski
In the crystal structure, the title compound {systematic name: [2,5-bis­(4-ethyl-3,5-dimethyl-2H -pyrrol-2-ylidene­meth­yl)-1H -pyrrolato](trifluoroacetato)palladium(II)}, [Pd(C2F3O2)(C27H34N3)], forms chiral mol­ecules with a helical distortion of the tripyrrinate ligand backbone and an essentially planar PdN3O core, with Pd,N distances ranging from 1.977,(3) to 2.045,(3),Å and a Pd,O distance of 2.051,(2),Å. This distortion of the organic ligand is considered as the conformational answer to the steric inter­action of the terminal methyl groups of the tripyrrinate ligand with the donor O atom of the trifluoro­acetate group. [source]

Ca0.8Y2.4Sn0.8O6, a quaternary oxide with mixed occupations of Ca/Y and Y/Sn

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2006
Yusuke Kaminaga
A new quaternary oxide, calcium yttrium stannate, Ca0.8Y2.4Sn0.8O6, is isostructural with Mg3TeO6 (trigonal, R). The empirical formula can be expressed as (Ca0.2667Y0.7333)6(Y0.4Sn0.6)SnO12. The Ca/Y site has a distorted coordination octa­hedron of O atoms, with Ca/Y,O distances ranging from 2.227,(3) to 2.350,(3),Å, while the octa­hedra of O atoms that coordinate to the Sn and Y/Sn sites are nearly regular, with an Sn,O distance of 2.066,(2),Å and a Y/Sn,O distance of 2.147,(3),Å. [source]

p -Chloro-, p -bromo- and two polymorphs of p -iodo­aceto­phenone

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2004
Doyle Britton
The title p -haloaceto­phenones, C8H7XO (X = Cl, Br and I), have different packing modes. The chloro compound contains H,O and H,Cl contacts, but no Cl,O contacts. The bromo compound and one polymorph (A) of the iodo compound are isomorphous, with significant X,O contacts [Br,O = 3.320,(4),Å and I,O = 3.374,(5),Å]. In the other polymorph (B) of the iodo compound, the I,O distance is 3.082,(4),Å. Both polymorphs contain C,H,, contacts; these contacts are shorter in A than in B. [source]

N - tert -Butyl- N,-(5,7-di­methyl-1,8-naphthyridin-2-yl)­urea

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2001
Ulrich Lüning
The title compound, C15H20N4O, has been synthesized as an AADD recognition unit for quadruple hydrogen bonds. All non-H atoms of the mol­ecule apart from two methyl groups of the tert -butyl group lie in a common plane. An intramolecular hydrogen bond is formed connecting two N atoms. In the solid state, the title compound crystallizes as a centrosymmetric dimer connected by N,H,O=C interactions with an N,O distance of 2.824,(2),Å. [source]

Hydro­gen bonds and C,H,O interactions in 2-(2-methyl­benzyl)­malonic acid at 150,K

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2000
Roger E. Gerkin
The title compound, C11H12O4, crystallized in the centrosymmetric space group Pbca with one mol­ecule as the asymmetric unit. The two hydrogen bonds have OD,OA distances of 2.667,(2) and 2.628,(2),Å, and O,H,O angles of 179,(2) and 177,(2)°. Each hydrogen bond forms an R(8) cyclic dimer about a center of symmetry. The leading intermolecular C,­H,O interaction has an H,O distance of 2.66,Å and a C,H,O angle of 160°. Taken together with the hydrogen bonds, it results in a three-dimensional network of inter­actions. The structure is compared with that of a close analog, benzyl­malonic acid. [source]

2-Bromo-5-hydroxy­benz­aldehyde

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2000
A. Matos Beja
The mol­ecules of the title compound, C7H5BrO2, form zigzag chains running along the b axis and are stacked in layers perpendicular to the a axis. Intermolecular bonding occurs through hydrogen bonds linking the hydroxyl and carbonyl groups, with an O,O distance of 2.804,(4),Å. The Br atom deviates significantly from the plane of the ring and the aldehyde group is twisted by 7.1,(5)° around the Csp2,Caryl bond. The geometry of the mol­ecule in the crystal is compared to that given by ab initio quantum mechanical calculations for the isolated mol­ecule, using a molecular orbital Hartree,Fock method and density functional theory. [source]

Spin State, Structure, and Reactivity of Terminal Oxo and Dioxygen Complexes of the (PNP)Rh Moiety

CHEMISTRY - A EUROPEAN JOURNAL, Issue 25 2008
Alexander
Abstract [RhIIIH{(tBu2PCH2SiMe2NSiMe2CH2PtBu{CMe2CH2})}], ([RhH(PNP*)]), reacts with O2 in the time taken to mix the reagents to form a 1:1 ,2 -O2 adduct, for which OO bond length is discussed with reference to the reducing power of [RhH(PNP*)]; DFT calculations faithfully replicate the observed O,O distance, and are used to understand the oxidation state of this coordinated O2. The reactivity of [Rh(O2)(PNP)] towards H2, CO, N2, and O2 is tested and compared to the associated DFT reaction energies. Three different reagents effect single oxygen atom transfer to [RhH(PNP*)]. The resulting [RhO(PNP)], characterized at and above ,60,°C and by DFT calculations, is a ground-state triplet, is nonplanar, and reacts, above about +15,°C, with its own tBu CH bond, to cleanly form a diamagnetic complex, [Rh(OH){N(SiMe2CH2PtBu2)(SiMe2CH2PtBu{CMe2CH2})}]. [source]

Crystal structure and thermal behaviour of (Rb,Cs)BSi2O6 solid solutions

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2006
M. G. Krzhizhanovskaya
Abstract The crystal chemistry of Rb-Cs boroleucites has been studied by means of X-ray powder diffraction at room and elevated temperatures. The cubic I-43d , cubic Ia3d phase transition was investigated using a series of samples prepared by solid-state reaction along the pseudobinary system RbBSi2O6 - CsBSi2O6. The Rietveld refinement of the structures of Rb1-xCsxBSi2O6 solid solutions (x = 0.2, 0.4, 0.6, 0.8) demonstrates that the solutions with a high Rb content crystallise in the cubic I-43d space group, and the boroleucites with a considerable Cs content have Ia3d symmetry. Rb can substitute Cs in a wide range of compositions. Within a narrow range of x = 0.5 - 0.6 immiscibility was revealed. Under Rb-Cs substitution the cubic lattice parameter, the (Rb,Cs)-O distances, and the angles between tetrahedra of the I-43d phase change clearly, while those of the Ia3d phase change slightly. The HTXRD data shows that the I-43d phase transforms into a Ia3d phase on heating analogously to a change of the composition. As the Cs content increases the transition temperature decreases. The low temperature I-43d phase shows a higher thermal expansion than the high temperature Ia3d phase. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [source]

Theoretical studies on high-valent manganese porphyrins: Toward a deeper understanding of the energetics, electron distributions, and structural features of the reactive intermediates of enzymatic and synthetic manganese-catalyzed oxidative processes

ISRAEL JOURNAL OF CHEMISTRY, Issue 1 2000
Abhik Ghosh
We present here a relatively comprehensive theoretical study, based on nonlocal density functional theory calculations, of the energetics, electron distributions, and structural features of the low-lying electronic states of various high-valent intermediates of manganese porphyrins. Two classes of molecules have been examined: (a) compounds with the general formula [(P)MnX2]0 (P = porphyrin; X = F, Cl, PF6) and (b) high-valent manganese-oxo species. For [(P)Mn(PF6)2]0, the calculations reveal a number of nearly equienergetic quartet and sextet states as the lowest states, consistent with experimental results on a comparable species, [(TMP)Mn(ClO4)2]0 (TMP = tetramesitylporphyrin). In contrast, [(P)MnCl2]0 and [(P)MnF2]0 have a single well-defined S = 3/2 Mn(IV) ground state, again in agreement with experiment, with the three unpaired spins largely concentrated (>90%) on the manganese atom. Manganese(IV)-oxo porphyrins have an S = 3/2 ground state, with the three unpaired spins distributed approximately 2.3:0.7 between the manganese and oxygen atoms. The metal-to-oxygen spin delocalization, as measured by the oxygen spin population, for MnIV = O porphyrins is less than, but still qualitatively similar to, that in analogous iron(IV)-oxo intermediates, indicating that the MnIV = O bond is significantly weaker than the FeIV = O bond in an analogous molecule. Thus, the optimized metal,oxygen bond distances are 1.654 and 1.674 Å for (P)FeIV(O)(Py) and (P)MnIV(O)(Py), respectively (Py = pyridine). This is consistent with the experimental observation that MnIV = O stretching frequencies are over 10% lower than FeIV = O stretching frequencies for analogous compounds. For [(P)Mn(O)(PF6)]0, [(P)Mn(O)(Py)]+, and [(P)Mn(O)(F)]0, the ground states clearly correspond to a (dxy)2 Mn(V) configuration and the short Mn,O distances of 1.541, 1.546, and 1.561 Å for the three compounds, respectively, reflect the formal triple bond character of the Mn,O interaction. Interestingly, the corresponding Mn(IV)-oxo porphyrin cation radical states are calculated to be a few tenths of an electrovolt higher than the Mn(V) ground states, suggesting that the Mn(IV)-oxo porphyrin cation radicals are not likely to exist as ground-state species. [source]

Local atomic structure in tetragonal pure ZrO2 nanopowders

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2010
Leandro M. Acuña
The local atomic structures around the Zr atom of pure (undoped) ZrO2 nanopowders with different average crystallite sizes, ranging from 7 to 40,nm, have been investigated. The nanopowders were synthesized by different wet-chemical routes, but all exhibit the high-temperature tetragonal phase stabilized at room temperature, as established by synchrotron radiation X-ray diffraction. The extended X-ray absorption fine structure (EXAFS) technique was applied to analyze the local structure around the Zr atoms. Several authors have studied this system using the EXAFS technique without obtaining a good agreement between crystallographic and EXAFS data. In this work, it is shown that the local structure of ZrO2 nanopowders can be described by a model consisting of two oxygen subshells (4 + 4 atoms) with different Zr,O distances, in agreement with those independently determined by X-ray diffraction. However, the EXAFS study shows that the second oxygen subshell exhibits a Debye,Waller (DW) parameter much higher than that of the first oxygen subshell, a result that cannot be explained by the crystallographic model accepted for the tetragonal phase of zirconia-based materials. However, as proposed by other authors, the difference in the DW parameters between the two oxygen subshells around the Zr atoms can be explained by the existence of oxygen displacements perpendicular to the z direction; these mainly affect the second oxygen subshell because of the directional character of the EXAFS DW parameter, in contradiction to the crystallographic value. It is also established that this model is similar to another model having three oxygen subshells, with a 4 + 2 + 2 distribution of atoms, with only one DW parameter for all oxygen subshells. Both models are in good agreement with the crystal structure determined by X-ray diffraction experiments. [source]

Temperature-dependent crystal structure refinement and 57Fe Mössbauer spectroscopy of Cu2Fe2Ge4O13

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2007
Günther J. Redhammer
The germanate compound Cu2Fe2Ge4O13, dicopper diiron germanate, was synthesized by solid-state reaction at 1403,K and ambient pressure. There is no change of space-group symmetry between 10 and 900,K. Between 40,K and room temperature the a lattice parameter shows a negative thermal expansion which can be connected to a decreasing Cu,Cu interatomic distance. Above room temperature all the lattice parameters are positively correlated with temperature. Among the structural parameters several alterations with temperature occur, which are most prominent for the distorted Fe3+ octahedral site. Besides an increase of the average bond length and of the interatomic Fe,Fe distances, distortional parameters also increase with temperature, while the average Cu,O bond length remains almost constant between 100 and 900,K, as do the average Ge,O distances. 57Fe Mössbauer spectroscopy was used to detect long-range magnetic ordering in Cu2Fe2Ge4O13. While around 100,K, which is the temperature at which a broad maximum is observed in the magnetic susceptibility, no magnetic ordering was detected in the Mössbauer spectrum, below 40,K a narrow split sextet is developed which is indicative of a three-dimensional magnetic ordering of the sample. [source]

Bi4Ge3O12 at the onset of pressure-induced amorphization

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009
Andrzej Grzechnik
The crystal structure of tetrabismuth tris(germanate), Bi4Ge3O12 (I3d, Z = 4), is stable to at least 7.30,GPa, as demonstrated by hydrostatic single-crystal X-ray diffraction measurements in a diamond anvil cell at room temperature. The highest pressure reached in this study is close to the onset of amorphization at about 8,GPa. The Bi and Ge atoms are located at the 16c (3) and 12a () Wyckoff positions, respectively. The compression mainly affects the distorted BiO6 octahedra, while the GeO4 tetrahedra are relatively rigid. When compared with the values obtained under ambient conditions, the long Bi,O distances decrease with increasing pressure, while the short Bi,O distances do not change. [source]

Ca0.8Y2.4Sn0.8O6, a quaternary oxide with mixed occupations of Ca/Y and Y/Sn

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2006
Yusuke Kaminaga
A new quaternary oxide, calcium yttrium stannate, Ca0.8Y2.4Sn0.8O6, is isostructural with Mg3TeO6 (trigonal, R). The empirical formula can be expressed as (Ca0.2667Y0.7333)6(Y0.4Sn0.6)SnO12. The Ca/Y site has a distorted coordination octa­hedron of O atoms, with Ca/Y,O distances ranging from 2.227,(3) to 2.350,(3),Å, while the octa­hedra of O atoms that coordinate to the Sn and Y/Sn sites are nearly regular, with an Sn,O distance of 2.066,(2),Å and a Y/Sn,O distance of 2.147,(3),Å. [source]

Two salts of di- p -toluoyltartaric acid with aromatic amines

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2006
Luigi R Nassimbeni
The structures of bis­[(R)-(+)-1-phenyl­ethyl­ammonium] (2R,3R)-(,)-2,3-di- p -toluoyloxybutane­dioate methanol disolvate monohydrate, 2C8H12N+·C20H16O82,·2CH4O·H2O, (I), and bis­(benzyl­ammonium) (2R,3R)-(,)-2,3-di- p -toluoyl­oxy­butane­­dioate dihydrate, 2C7H10N+·C20H16O82,·2H2O, (II), exhibit extensive hydrogen bonding, with (N,)H,O and (O,)H,O distances in the ranges 2.716,(2),2.929,(3) and 2.687,(2),2.767,(2),Å, respectively, in (I), and 2.673,(2),2.888,(2) and 2.785,(2),2.931,(2),Å, respectively, in (II). The amine groups are protonated and the carboxyl­ate groups of the tartrate anions are fully deprotonated. The conformation of the toluoyltartrate anion and its mol­ecular parameters are similar in both structures. [source]

Crystallographic report: Bis(norfloxacin)dilead(II) tetranitrate, [Pb2(H-Norf)2(ONO2)4]

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2003
Zhen-Feng Chen
Abstract The centrosymmetric binuclear structure of [Pb2(H-Norf)2(ONO2)4]shows the geometry around each lead(II) atom to be distorted trigonal bipyramidal with Pb,O distances ranging from 2.357(3) to 2.769(4) Å. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Tetra­aqua­cobalt(II) bis­[vanadyl(IV) phosphate], [Co(H2O)4][VO(PO4)]2

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2003
Bi-Zhou Lin
The structure of [Co(H2O)4][VO(PO4)]2 is composed of [VO(PO4)] layers and interlayer tetrahydrated Co2+ ions. Alternating VO5 square pyramids and PO4 tetrahedra share O-atom vertices, thus forming the vanadyl phosphate layers. Two vanadyl oxo groups from neighbouring layers are coordinated to each Co atom in a trans fashion, with Co,O distances of 2.157,(4),Å, thus generating a three-dimensional framework structure. [source]

(K4Li4)Al8Ge8O32·8H2O: an Li+ -exchanged potassium aluminogermanate with the zeolite gismondine (GIS) topology

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2003
Aaron J. Celestian
The title compound, lithium potassium dialuminium di­ger­man­ium octaoxide dihydrate, (K,Li)-(Al,Ge)-GIS (GIS is gismondine), is the result of a 50% Li+ exchange into the K-(Al,Ge)-GIS structure. The (K,Li)-(Al,Ge)-GIS structure was determined from a 4,×,4,×,2,µm octahedral single crystal at the ESRF synchrotron X-ray source. The ion exchange results in a symmetry transformation from I2/a for K-(Al,Ge)-GIS to C2/c for (K,Li)-(Al,Ge)-GIS. The structural change is due to disordering of K+ ions with Li+ ions along the [001] channel and ordering of water molecules in the [101] channels. The distance between sites partially occupied by K+ ions increases from 2.19,(3),Å in K-(Al,Ge)-GIS to 2.94,(3),Å in (K,Li)-(Al,Ge)-GIS. The Li+ ions occupy positions along the twofold axis at the intersection of the eight-membered-ring channels in a twofold coordination with water mol­ecules. For the four closest framework O2, anions, the Li,O distances are 3.87,(4),Å. [source]

Enantiomeric bis(,- N,N,-hexamethylenedisalicylaldiminato)dicopper(II) complexes

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2002
Tomislav Fri
The title dimeric complex, bis{,-2,2,-[hexane-1,6-diyl­bis(nitrilo­methyl­idyne)]­diphenolato-1:2,4O,N:N,,O,}dicopper(II),[Cu2(C20H22N2O2)2], has been investigated by single-crystal X-ray diffraction, by thermogravimetric analysis and differential scanning calorimetry, and also by FT,IR spectroscopy. Different synthetic and crystallization procedures gave crystals which were quite different in appearance, and it was initially thought that these were different polymorphic forms. Subsequent structure determination showed, in fact, serendipitous preparation of crystals in the P41 space group by one method and in space group P43 by the other. In these enantiomorphic structures, the Cu atoms have a distorted flattened tetrahedral coordination, with Cu,N and Cu,O distances in the ranges 1.954,(4),1.983,(4) and 1.887,(4),1.903,(4),Å, respectively. [source]

cis -Bis(di­methyl sulfoxide- S)­dinitrato­palladium(II) and cis -dinitratobis(1,4-oxathiane- S)­palladium(II)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2001
Maria H. Johansson
The Pd atom in each of the two title compounds, [Pd(NO3)2(C2H6OS)2], (I), and [Pd(NO3)2(C4H8OS)2], (II), coordinates two O atoms from two nitrate ligands and two S atoms from di­methyl sulfoxide (dmso) and thio­xane (systematic name: 1,4-oxathiane) ligands in a pseudo-square-planar cis -geometry. In the dmso complex, the distances to palladium are Pd,O 2.067,(2) and 2.072,(2),Å, and Pd,S 2.2307,(11) and 2.2530,(8),Å. The corresponding distances in the thio­xane complex are Pd,O 2.053,(3) and 2.076,(2),Å, and Pd,S 2.2595,(9) and 2.2627,(11),Å. Both compounds may be regarded as dimers with an inversion centre, where one of the coordinating nitrate O atoms in one mol­ecule also interacts with the Pd atom in the adjacent mol­ecule, with Pd,O distances of 2.849,(9) and 3.31,(3),Å in (I) and (II), respectively. [source]

Alkaline metal oxoantimonates(III), A3[SbO3] (A = K or Cs)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2001
Franziska Emmerling
The two title trialkaline trioxoantimonates(III), tripotassium trioxoantimonate(III), K3[SbO3], (I), and tricaesium trioxo­antimonate(III), Cs3[SbO3], (II), crystallize in the cubic Na3[AsS3] structure type in space group P213. The structures show discrete ,-tetrahedral [SbO3]3, anions with C3v point-group symmetry. The Sb,O distances are 1.923,(4),Å in (I) and 1.928,(2),Å in (II), and the O,Sb,O bond angles are 99.5,(2)° in (I) and 100.4,(1)° in (II). [source]

Bis(2-amino­pyridine- N)­bis­(benzoato- O)­zinc

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2000
S. Shanmuga Sundara Raj
The crystal structure of the title compound, [Zn-(C7H5O2)2(C5H6N2)2], is built of monomeric [Zn(2-apy)2(OBz)2] mol­ecules (apy is amino­pyridine and OBz is benzoate). The Zn atom lies on a twofold symmetry axis and adopts a slightly distorted tetrahedral coordination. The Zn,O distances to the non-coordinated O atoms are long at 2.872,(3),Å. Each non-ligating carbonyl O atom of the benzoate anion accepts one intramolecular and one intermolecular hydrogen bond from the amino group. The mol­ecules form a chain along the c axis through intermolecular N,H,O hydrogen bonds between the amino and carboxyl groups. [source]

2,4,4-Tri­methyl-2-phenyl-3-pentanone oxime

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2000
Rudy L. Luck
The title compound, C14H21NO, has two mol­ecules in the asymmetric unit. Each mol­ecule forms hydrogen-bonded dimers about inversion centers via O,H,N hydrogen bonds between oxime groups. The N,O distances in the oxime groups are 1.4160,(15) and 1.4131,(14),Å. [source]

Intermolecular hydrogen bonding of the two independent mol­ecules of N -3,5-di­nitro­benzoyl- l -leucine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2000
John F. Gallagher
The title compound, C13H15N3O7, crystallizes as two independent mol­ecules which differ in their conformation. Intermolecular hydrogen bonding between the amide and carboxyl­ic acid groups as N,H,O=C interactions results in the formation of one-dimensional chains with N,O distances of 2.967,(6) and 3.019,(6),Å. Neighbouring chains are linked by C=O,H,O interactions to form a two-dimensional network, with O,O distances of 2.675,(6) and 2.778,(6),Å. [source]