Acta Crystallographica. Section C, Crystal Structure Communications

The structures of the hydrated sodium salts of 4-chloro-3-nitrobenzoic acid {poly[aqua(μ4-4-chloro-3-nitrobenzoato)sodium(I)], [Na(C7H3ClNO4)(H2O)]n, (I)} and 2-amino-4-nitrobenzoic acid {poly[μ-aqua-aqua(μ3-2-amino-4-nitrobenzoato)sodium(I)], [Na(C7H5N2O4)(H2O)2]n, (II)}, and the hydrated potassium salt of 2-amino-4-nitrobenzoic acid {poly[μ-aqua-aqua(μ5-2-amino-4-nitrobenzoato)potassium(I)], [K(C7H5N2O4)(H2O)]n, (III)} have been determined and their complex polymeric structures described. All three structures are stabilized by intra- and intermolecular hydrogen bonding and strong π-π ring interactions...

The Re(I) centres of two Re(I)-tricarbonyl complexes, viz. tricarbonyl(pyridine-κN){5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olato-κ(2)N(1),O}rhenium(I), [Re(C23H21N4O)(CO)3], (I), and {5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olato-κ(2)N(1),O}tricarbonyl(pyridine-κN)rhenium(I), [Re(C28H23N6O)(CO)3], (II), are facially surrounded by three carbonyl ligands, a pyridine ligand and either a 5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olate [in (I)] or a 5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olate [in (II)] ligand, in a slightly distorted octahedral environment...

The rhodium complexes [RhCl3(NH3)3], (I), and [Rh(NO3)3(NH3)3], (II), are built from octahedral RhX3(NH3)3 units; in (I) they are isolated units, while in (II) the units are stacked in columns with partially filled sites for the Rh atoms. The octahedra of monoclinic crystals of (I) are linked by N-H···Cl hydrogen bonds and the Rh(3+) ions are located on the mirror planes. In the trigonal crystals of (II), the discontinuous `columns' along the threefold axis are linked by N-H···O hydrogen bonds. The structure of (I) has been solved using laboratory powder diffraction data, the structure of (II) has been solved by single-crystal methods using data from a merohedrally twinned sample...

Studies in the Rb-Eu-In-Ge system confirm the existence of the phase Rb(8-x)Eu(x)(In,Ge)46 (0.6 ≤ x ≤ 1.8), crystallizing with the cubic clathrate type-I structure. The In and Ge content can be varied, concomitant with changes in the Rb-Eu ratio. Two of the three framework sites are occupied by statistical mixtures of Ge and In atoms, while the site with the lowest multiplicity is taken by the In atoms only. Based on the three refined formulae [heptarubidium europium nonaindium heptatriacontagermanide, Rb7...

Over the last 30 years, the single-crystal photocrystallographic technique has been developed to determine the three-dimensional crystal and molecular structures of metastable species which have been generated in the crystal photochemically. Transition-metal complexes that have been investigated using this methodology include complexes that contain nitrosyl, dinitrogen, sulfur dioxide and nitrite ligands, all of which form new linkage isomers in the solid state when photoactivated by light of the appropriate wavelength...

The complex [1,2-bis(di-tert-butylphosphanyl)ethane-κ(2)P,P']diiodidonickel(II), [NiI2(C18H40P2] or (dtbpe-κ(2)P)NiI2, [dtbpe is 1,2-bis(di-tert-butylphosphanyl)ethane], is bright blue-green in the solid state and in solution, but, contrary to the structure predicted for a blue or green nickel(II) bis(phosphine) complex, it is found to be close to square planar in the solid state. The solution structure is deduced to be similar, because the optical spectra measured in solution and in the solid state contain similar absorptions...

NMR diffusion methods continue to attract increasing attention from practising chemists. This short article summarizes some of the more recent developments and highlights the areas in which these methods are finding application, specifically: estimating molecular volumes; investigating the degree of aggregation (especially in salts); studying host-guest interactions; recognizing hydrogen bonds; and directly proving the presence and extent of ion pairing.

The development of powder diffraction is briefly described; the extent of this development from studies of metals to protein crystal structures shows that powder diffraction is at the cutting edge of crystallography. A new name `polycrystallography' is proposed for these endeavours.

The crystal structure of a tin-rich heterometallic supramolecular product, [CuSn8(C5HF6O2)2(C5H2F6O4)4] or [Sn4(hfpt)2-Cu(hfac)2-Sn4(hfpt)2], (I), is reported (hfpt is the tetraanion of 1,1,1,5,5,5-hexafluoropentane-2,2,4,4-tetraol and hfac is the anion of 1,1,1,5,5,5-hexafluoropentane-2,4-dione). Reaction between tin(II) tetraolate, [Sn4(hfpt)2], and copper(II) β-diketonate, [Cu(hfac)2], was utilized for the preparation of (I). The asymmetric unit consists of the whole [Sn4(hfpt)2] unit and half of a [Cu(hfac)2] unit, with the Cu atom lying on an inversion center...

As part of our search for catalytically active Ru(II)-hydride complexes, we have synthesized and crystallographically characterized three different ruthenium species, namely dihydrido[(SR)-(10,11-η)-N-(pyridin-2-ylmethyl-κN)-5H-dibenzo[a,d]cyclohepten-5-amine](triphenylphosphane-κP)ruthenium(II) tetrahydrofuran monosolvate, [RuH2(C21H18N2)(C18H15P)]·C4H8O or (SR)-[Ru(II)(H)2{N-(pyridin-2-ylmethyl)tropNH}(PPh3)]·THF, (1), chlorido{(1SR,2RS)-N,N'-bis[(10,11-η)-5H-dibenzo[a,d]cyclohepten-5-amine]ethane-1,2-diamine-κ(2)N,N'}hydridoruthenium(II) dimethoxyethane hemisolvate, [RuClH(C32H28N2)]·0...

The mixed-valence supramolecular product di-μ2-acetone-di-μ3-trifluoroacetato-deca-μ2-trifluoroacetato-octacopper(I)dicopper(II), [Cu10(C2F3O2)12(C3H6O)2] or {[Cu(I)4(O2CCF3)4]2-{μ2-OC(CH3)2}2-[Cu(II)2(O2CCF3)4]}, was prepared by co-deposition of two building units, namely a bis-acetone adduct of [Cu(II)2(O2CCF3)4] and a very electrophilic tetranuclear [Cu(I)4(O2CCF3)4] complex. The asymmetric unit contains one molecule of the compound with a total of ten independent Cu atoms. Acetone molecules serve as bridges between the [Cu(II)2(O2CCF3)4] and [Cu(I)4(O2CCF3)4] units...

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The absolute configuration has been established of the enantiopure anti-head-to-head cyclodimer of anthracene-2-carboxylic acid (AC) cocrystallized with L-propinol and dichloromethane [systematic name: (S)-2-(hydroxymethyl)pyrrolidin-1-ium (5R,6S,11R,12S)-8-carboxy-5,6,11,12-tetrahydro-5,12:6,11-bis([1,2]benzeno)dibenzo[a,e][8]annulene-2-carboxylate dichloromethane monosolvate], C5H12NO(+)·C30H19O4(-)·CH2Cl2. In the crystal structure, the AC dimer interacts with L-prolinol through a nine-membered hydrogen-bonded ring [R2(2)(9)], while the dichloromethane molecule is incorporated to fill the void space...

The molecular structure of the title compound, C21H19Cl2N3O2, a potent glycogen phosphorylase a (GPa) inhibitor (IC50 of 6.3 µM), consists of four distinct conjugated π systems separated by rotatable C-C bonds at the methylene groups. Molecules are linked into dimers disposed about a crystallographic centre of symmetry through a cyclic N-H...O hydrogen-bonding motif [graph set R2(2)(10)]. These dimers are further connected along the crystallographic c axis by N-H...O hydrogen bonding between the amide groups [graph set C(4)]...

Since 6-aminouracil derivatives show diversified use in various fields of application, we crystallized 6-aminouracil to examine its preferred hydrogen-bonding frameworks. 6-Aminouracil shows two rigid hydrogen-bonding sites, viz. one acceptor-donor-acceptor (ADA) site and one donor-donor-acceptor (DDA) site. During various crystallization attempts, we obtained three structures, namely two dimethylacetamide monosolvates, C4H5N3O2·C4H9NO, and a 1-methylpyrrolidin-2-one monosolvate, C4H5N3O2·C5H9NO. In all three structures, R2(1)(6) N-H...

The molecular and supramolecular structures are reported of N-[2-(pyridin-2-yl)ethyl]methanesulfonamide, C8H12N2O2S, (I), N-[2-(pyridin-2-yl)ethyl]benzenesulfonamide, C13H14N2O2S, (II), and N-[2-(pyridin-2-yl)ethyl]toluenesulfonamide, C14H16N2O2S, (III). Although (II) and (III) are almost structurally identical, the N(amide)-C(ethyl)-C(ethyl)-C(pyridinyl) torsion angles for (I) and (II) are more closely comparable, with magnitudes of 175.37 (15)° for (I) and 169.04 (19)° for (II). This angle decreases dramatically with an additional methyl group in the para position of the sulfonamide substituent, resulting in a value of 62...

The title compounds, N-acetyl-L-proline monohydrate, C7H11NO3·H2O, (I), and N-benzyl-L-proline, C12H15NO2, (II), crystallize in the monoclinic space group P21 with Z' = 1 and Z' = 2, respectively. The conformation of C(γ) with respect to the carboxylic acid group in (I) is C(γ)-exo or UP pucker, with the pyrrolidine ring twisted, while in (II), it is C(γ)-endo or DOWN, with the pyrrolidine ring assuming an envelope conformation. The crystal packing interactions in (I) are composed of two substructures, one characterized by an R6(6)(24) motif through O-H...

2,4-Dinitro-N-(2-phenylethyl)aniline, C14H13N3O4, (I), crystallizes with one independent molecule in the asymmetric unit. The adjacent amine and nitro groups form an intramolecular N-H...O hydrogen bond. The anti conformation about the ethyl C-C bond leads to the phenyl and aniline rings being essentially parallel. Molecules are linked into dimers by intermolecular N-H...O hydrogen bonds, such that each amine H atom participates in a three-centre interaction with two nitro O atoms. Though the dimers pack so that the arene rings of adjacent molecules are parallel, the rings are staggered and π-π interactions do not appear to be favoured...

The title mononuclear complex, [Nd(C5H3N2O3)3(H2O)3]·3H2O, consists of an Nd(III) cation, three 2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate ligands and three aqua ligands forming the neutral complex molecule, and three solvent water molecules. The pyrimidinecarboxylate ligands act in a chelating manner, via carboxylate and keto O atoms. The NdO9 coordination polyhedron is in the form of a distorted monocapped square antiprism. The availability of numerous hydrogen-bonding donors and acceptors results in a very dense hydrogen-bonding network, the immediate effect of which is an unusually large packing index...

In the Cu(II) compound catena-poly[[copper(II)-μ-[2-({2-[2-(naphthalen-2-yloxy)-1-oxidoethylidene]hydrazin-1-ylidene}methyl)phenolato]] dimethylformamide monosolvate monohydrate], {[Cu(C19H14N2O3)]·C3H7NO·H2O}n, (I), the Cu(II) cation is O,N,O'-chelated by one ligand and further N,O-chelated by a second ligand, and exhibits a distorted square-pyramidal coordination environment. The ligand acts as an overall pentadentate bridge between two metal ions, thus forming a novel coordination polymer. In the trinuclear Ni(II) compound diaquabis(1H-imidazole)bis[μ-2-oxido-N'-(1-oxido-2-phenoxyethylidene)benzohydrazidato]trinickel(II) dimethylformamide tetrasolvate, [Ni3(C15H11N2O4)2(C3H4N2)2(H2O)2]·4C3H7NO, (II), the three Ni(II) cations are directly linked by two trans diazine (N-N) bridges and are strictly collinear by symmetry...