The title compound, Yb2LiInGe2, a new ordered quaternary intermetallic phase, crystallizes with the orthorhombic Ca2LiInGe2 type (Pearson code oP24). The crystal structure contains six crystallographically unique sites in the asymmetric unit, all in special positions with site symmetry .m.. The structure is complex and based on [InGe4] tetrahedra, which share corners in two directions, forming layers parallel to (001). Yb atoms fill square-pyramidal (Yb1) and octahedral (Yb2) interstices between the [InGe4/2] layers, while the small Li+ atoms fill tetrahedral sites.
In the title compound, C37H32F2N2O2, the central six-membered piperidine ring adopts a twisted half-chair conformation, with the N and methylene C atoms deviating by −0.2875 (16) and 0.4965 (15) Å, respectively, from the mean plane defined by the other four atoms. The piperidine connected to the octahydroindolizine ring is in a half-chair conformation. The five-membered pyrrole ring adopts a slightly twisted envelope conformation with the piperidine C atom as the flap atom. The F and H atoms of both fluorobenzene rings are disordered, with occupancy factors of 0.941 (3):0.059 (3) and 0.863 (3):0.137 (3). The molecular structure features some intramolecular C—H⋯O interactions. In the crystal, a supramolecular zigzag chain sustained by C—H⋯F interactions parallel to the c axis is formed, generating a C(12) graph-set motif.
A new monoclinic polymorphic form of the title compound, [Cu(HCO2)2(C14H12N2)(H2O)], is described. It differs from the first orthorhombic polymorph [Pan, Lin & Zheng (2005 ▶). Z. Kristallogr. New Cryst. Struct.
220, 495–496] in the deviation of the Cu atom relative to the plane of the 2,9-dimethyl-1,10-phenanthroline (dmp) ligand. In the present structure, the Cu atom is shifted from the mean plane of the dmp ligand by only 0.005 (1) Å, compared with 0.318 (6) Å in the orthorhombic form. Hydrogen-bonding and π–π stacking interactions (mean interplanar distance of 3.59 Å in the title compound) in the two different polymorphs are both essential to the supramolecular assembly.
The title compound, C13H10Cl2N2S, represents a monoclinic polymorph of the previously reported orthorhombic form [Ramnathan et al. (1996 ▶). Acta Cryst. C52, 134–136]. The molecule is twisted with the dihedral angle between the benzene rings being 55.37 (7)°. The N—H atoms are syn to each other, which contrasts their anti disposition in the orthorhombic form. In the crystal, molecules assemble into zigzag chains along the c axis via N—H⋯S hydrogen bonds. Chains are connected into layers via C—H⋯Cl interactions, and these stack along the a axis.
The N-oxide O atom of the minoxidil unit in the 1/1 adduct with lead(II) iodide, [PbI2(C9H15N5O)]n, bridges two PbII atoms, as do each of the I atoms. The bridging interactions give rise to a linear chain motif that propagates along the a axis of the orthorhombic unit cell. The coordination sphere around the six-coordinate PbII atom is a distorted ψ-monocapped octahedron in which the stereochemically active lone pair caps one of the faces defined by the O and I atoms forming the longer Pb—O or Pb—I bonds. The PbII atom lies on a mirror plane; the mirror plane is perpendicular to the pyrimidine ring and it bisects the piperidine ring. The aromatic ring is disordered about the mirror plane with respect to the 1-nitrogen and 5-carbon atoms.
A new polymorph of N,N′-bis(2,6-diisopropylphenyl)formamidine, C25H36N2, is reported, which is different from the previously reported orthorhombic structure. The molecule crystallizes in the E–anti configuration, with tautomeric disorder of the N-bonded H atoms and no clear distinction between imine and amine functionalities. The molecules form hydrogen-bonded dimers with intermolecular N⋯N distances shorter than those in the orthorhombic polymorph.
The title heteroaryl chalcone, C21H14OS, is a second orthorhombic polymorph which crystallizes in the space group P212121. The structure was previously reported [Fun et al. (2009 ▶). Acta Cryst. E65, o2168-o2169] in the space group Pna21. The bond distances and angles are similar in both structures. In contrast, the overall crystal packing is different from that in the first orthorhombic Pna21 polymorph in which molecules were stacked into columns along the b axis and the thiophene units of two adjacent columns were stacked in a head to tail fashion. In the present polymorph, molecules are found to dimerize through a weak S⋯S interaction [3.6513 (7) Å] and these dimers are arranged into sheets parallel to the bc plane. There are no classical hydrogen bonds in the packing which features short C⋯O [3.2832 (2)–3.6251 (9) Å], C⋯S [3.4879 (17)–3.6251 (19) Å] and S⋯O [2.9948 (16) Å] contacts, together with C—H⋯π interactions. Similar contacts were found in the other polymorph.
In the aminal-type title compound, C10H15N3, the six-membered hexahydropyrimidine ring adopts a chair conformation and the N atoms are pyramidally coordinated. One of the two amido –NH units engages in intermolecular hydrogen bonding with the pyridyl N atom, generating a helical chain running along the b axis of the orthorhombic unit cell.
In the crystal structure of the title compound, C43H34N3O5
−·C3H6O, the large dimension and shape of the cation are responsible for the elongation of the orthorhombic unit cell. The ions and acetone molecules are linked together by a system of hydrogen bonds involving an intermolecular hydrogen bond between one N atom of the cation and the O atom of acetone and two intermolecular hydrogen bonds between the cation N atoms and the O atoms of the picrate anion. No intramolecular hydrogen bonds exist in the structure. The dihedral angle between the two naphthalene ring systems is 76.16 (13)°. The chiral C atom has a known R configuration, but this cannot be confirmed from this X-ray analysis.
In the solid-state synthesis of impurity-doped CaGa2S4, calcium tetrathiodigallate(III), a novel phosphor material (denominated as the X-phase), with monoclinic symmetry in the space group P21/a, has been discovered. Its emission intensity is higher than that of the known orthorhombic polymorph of CaGa2S4 crystallizing in the space group Fddd. The asymmetric unit of the monoclinic phase consists of two Ca, four Ga and eight S sites. Each of the Ca and Ga atoms is surrounded by seven and four sulfide ions, respectively, thereby sharing each of the sulfur sites with the nearest neighbours. In contrast, the corresponding sites in the orthorhombic phase are surrounded by eight and four S atoms, respectively. The photoluminescence peaks from Mn2+ and Ce3+ in the doped X-phase, both of which are supposed to replace Ca2+ ions, have been observed to shift towards the high energy side in comparison with those in the orthorhombic phase. This suggests that the crystal field around the Mn2+ and Ce3+ ions in the X-phase is weaker than that in the orthorhombic phase.
The quaternary thiophosphate, Cs0.49NbPS6, caesium hexathioniobiophosphate(V), has been synthesized by the reactive halide flux method. The title compound is isotypic with Rb0.46TaPS6 and is made up of a bicapped trigonal–biprismatic [Nb2S12] unit and a tetrahedral [PS4] group. The [Nb2S12] units linked by the [PS4] tetrahedra form infinite chains, yielding a three-dimensional network with rather large van der Waals gaps along the c axis in which the disordered Cs+ ions reside. The electrons released by the Cs atoms are transferred to the pairwise niobium metal site and there are substantial intermetallic Nb—Nb bonding interactions. This leads to a significant decrease of the intermetallic distance in the title compound compared to that in TaPS6. The classical charge balance of the title compound may be represented as [Cs+]0.49[Nb4.51+][P5+][S2−]4[S2
A new monoclinic polymorph of the title compound, [V2(C10H13N2O)2O4], which is a centrosymmetric dimer, crystallizes in space group P21/c, whereas the previously known polymorph crystallizes in the orthorhombic space group Pbca [Mokry & Carrano (1993 ▶). Inorg. Chem.
32, 6119–6121]. Each VV atom is six-coordinated by one oxide group, two N atoms and one O atom from the Schiff base ligand, and by two additional bridging O atoms. The two methylene groups are each disordered over two sites, with occupancy factors of 0.776 (14) and 0.224 (14). In the crystal structure, there are C—H⋯O hydrogen bonds and C—H⋯π interactions between the dimers.
The crystal structure of the title compound, C12H11NO2, represents a new orthorhombic polymorph II of the previously reported orthorhombic form I [Zhang et al. (2009 ▶) Acta Cryst. E65, o3160]. In polymorph II, the six-membered rings form a dihedral angle of 13.8 (1)° [71.6 (1)° in I], and O—H⋯N hydrogen bonds link molecules into chains along , whereas the crystal structure of I features hydrogen-bonded centrosymmetric dimers.
The CuII atom in the title compound, [Cu(C13H16ClN2O2)Cl], exists in a distorted square-planar coordination environment as the deprotonated Schiff base chelates to the CuII atom through three atom sites. In the crystal structure, adjacent molecules are linked by a Cu⋯Cl [3.011 (1) Å] bridge, generating a linear chain running along the b axis of the orthorhombic unit cell.
The seven-membered ring in the title compound, C15H12N2O, adopts a boat-shaped conformation (with the methylene C atom as the prow and the double-bond C=N pair of atoms as the stern). In the crystal, adjacent molecules are linked by an N—H⋯O hydrogen bond to generate helical chains running along the a axis of the orthorhombic unit cell.
A monoclinic polymorph of the title compound, [Na(C4H5O6)(H2O)]n, is reported and complements an orthorhombic form [Kubozono, Hirano, Nagasawa, Maeda & Kashino (1993 ▶). Bull. Chem. Soc. Jpn, 66, 2166–2173]. The asymmetric unit contains a hydrogen tartrate anion, an Na+ cation and a water molecule. The Na+ ion is surrounded by seven O atoms derived from one independent and three symmetry-related hydrogen tartrate anions, and a water molecule, forming a distorted pentagonal–bipyramidal geometry. Independent units are linked via a pair of intermolecular bifurcated O—H⋯O acceptor bonds, generating an R
1(6) ring motif to form polymeric two-dimensional arrays parallel to the (100) plane. In the crystal packing, the arrays are linked by adjacent ring motifs, together with additional intermolecular O—H⋯O interactions, into a three-dimensional network.
The title complex, [Cd(C6H2N2O4)(H2O)3]n, is a new monoclinic polymorph. The orthorhombic form has previously been reported [Ma et al. (2006 ▶). Acta Cryst. E62, m2528–m2529]. The Cd—N and Cd—O bond lengths range from 2.265 (3) to 2.333 (3) Å; a weak Cd—O interaction is also present, the interatomic distance being 2.658 (4) Å. The CdII ions, which have a distorted pentagonal-bipyramidal geometry, are bridged by pyrazine-2,3-dicarboxylato ligands, forming a zigzag chain structure. The chains are connected by O—H⋯O hydrogen bonds into a three-dimensional framework.
During an attempt to prepare a cocrystal of N-phenylphthalimide, C14H9NO2, with N-(2,3,4,5,6-pentafluorophenyl)phthalimide, a new orthorhombic polymorph of the first component was obtained. This new form has Z′ = 0.5 and the molecule is located around a twofold axis, whereas in the previously reported polymorph (space group Pbca), the molecule has no crystallographically imposed symmetry. Pairs of C—H⋯O interactions between inversion-related phthalimide units arrange molecules into tapes that are further assembled into (010) layers via stacking interactions between phthalimide fragments [interplanar distance = 3.37 (5) Å].
The title salt, C12H24N+·NCS−, represents a monoclinic polymorph of the previously reported orthorhombic form [Khawar Rauf et al. (2008 ▶). Acta Cryst. E64, o366]. Two independent formula units comprise the asymmetric unit with the major difference in their molecular structures relating to the relative dispositions of the cyclohexyl rings [dihedral angles = 79.88 (6) and 67.72 (5)°]. Further, the independent anions form distinctive patterns of hydrogen-bonding interactions, i.e. 2 × N—H⋯N versus N—H⋯N and N—H⋯S. The resulting supramolecular architecture is a supramolecular chain along the c axis based on a square-wave topology.
Crystals of the orthorhombic phase La4Mo7O27 (lanthanum molybdenum oxide) were obtained from a non-stoichiometric melt in the pseudo-ternary system La2O3–MoO3–B2O3. In the crystal structure, distorted square-antiprismatic [LaO8] and monocapped square-antiprismatic [LaO9] polyhedra are connected via common edges and faces into chains along . These chains are arranged in layers that alternate with layers of [MoO4] and [MoO5] polyhedra parallel to (001). In the molybdate layers, a distorted [MoO5] trigonal bipyramid is axially connected to two [MoO4] tetrahedra, forming a [Mo3O11] unit.
A new polymorph of the title compound, C8H8BrNO, has been determined at 173 K in the space group P21/c. The previous room-temperature structure was reported to crystallize in the orthorhombic space group Pna21 [Andreetti et al. (1968 ▶). Acta Cryst. B24, 1195–1198]. In the crystal, molecules are linked by N—H⋯O hydrogen bonds forming chains along . Weak C—H⋯π interactions are also present.
The new terbium (lithium zinc) distannide, TbLi1–xZnxSn2 (x = 0.2) crystallizes in the orthorhombic CeNiSi2 structure type with space group Cmcm and Pearson symbol oS16. Of the four independent 4c atom positions (m2m site symmetry), three are fully occupied by individual atoms (two by Sn and one by Tb atoms) and the fourth is occupied by Li and Zn atoms with a statistical distribution. The Tb coordination polyhedron is a 21-vertex pseudo-Frank–Kasper polyhedron. One Sn atom is enclosed in a tricapped trigonal prism, the second Sn atom is in a cuboctahedron and the statistically distributed (Li,Zn) site is in a tetragonal antiprism with one added atom. Electronic structure calculations were used for the elucidation of reasons for and the ability of mutual substitution of lithium and transition metals. Positive charge density was observed around the rare earth atom and the Li and Zn atoms, the negative charge density in the proximity of the Sn atoms.
Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4):0.033 (4) and 0.031 (3):0.969 (3), one site (.m. symmetry) is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry) are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the trigonal-prismatic voids.
The title compound, C18H14O, is polymorphic at 123 K. The orthorhombic form reported herein has two independent molecules in the asymmetric unit, with molecular volume 313.5 Å3. The previously reported triclinic (P-1) form [Raston & Scott (2000 ▶). Green Chem., 2, 49–52] has molecular volume 309.6 Å3 at the same temperature. All three molecules deviate significantly and systematically from the putative Cs symmetry (δr.m.s. = 0.0265, 0.0256, 0.0497 Å). Comparison of the two molecules in the orthorhombic polymorph shows that 16 of the 19 equivalent pairs of framework atoms have a mirror-image pattern of deviations (above/below plane), suggesting that the two are quasi-enantiomorphs. The pattern of deviations in the triclinic form is nearly the same (13 of 19 atom pairs) as the orthorhombic form.
The title compound, C4H8O4Te, crystallized from a solution of Te4+ in ethylene glycol. The TeIV atom is in a distorted seesaw coordination defined by four O atoms from two different ethyleneglycate ligands. The C atoms of the ethyleneglycate ligands are disorderd over two positions, with population parameters of 50.3 (6) and 49.7 (6)% indicating a statistical distribution. Due to the possibility to transform the primitive monoclinic unit cell into a metrically orthorhombic C unit cell, the data are twinned and were refined with the twin law -100/0-10/101 with the relative scale factor refining to 1.82 (4)% for the minor component.