The title compound, C9H11N3O2S, is a second monoclinic (P21/c) polymorph of the previously reported Cc form [Tan et al. (2008b ▶). Acta Cryst. E64, o2224]. The mol-ecule is non-planar, with the dihedral angle between the N3CS residue (r.m.s. deviation = 0.0816 Å) and the benzene ring being 21.36 (4)°. The conformation about the C=N bond [1.292 (2) Å] is E, the two N-bound H atoms are anti, and the inner hy-droxy O-bound and outer amide N-bound H atoms form intra-molecular hydrogen bonds to the imine N atom. Crucially, the H atom of the outer hy-droxy group is approximately syn to the H atom of the benzene C atom connecting the two C atoms bearing the hy-droxy substituents. This arrangement enables the formation of supra-molecular tubes aligned along [010] and sustained by N-H⋯O, O-H⋯S and N-H⋯S hydrogen bonds; the tubes pack with no specific inter-actions between them. While the mol-ecular structure in the Cc form is comparable, the H atom of the outer hy-droxy group is approximately anti, rather than syn. This different orientation leads to the formation a three-dimensional architecture based on N-H⋯O and O-H⋯S hydrogen bonds.
Noncovalent interactions are prevalent in crystal packing and supramolecular chemistry. Directional noncovalent interactions such as donor-acceptor bonds (e.g., hydrogen, chalcogen, and pnictogen bonds) as well as nondirectional forces (such as dispersion) come together to stabilize supramolecular assemblies by striking a delicate energetic balance. Typically, a two-pronged approach employing experimental X-ray structures and gas phase quantum chemical modeling has been used to understand and design supramolecular architectures. Drawing from recent advances in molecular crystal modeling with dispersion corrected density functional theory (DFT), we propose in this article a combination of qualitative noncovalent index (NCI) analysis and periodic and gas phase DFT calculations on substitutional crystal analogues to unravel the dominant interactions in a particular crystal packing. We illustrate the possibilities of this approach by studying three crystal packings of epoxydihydroarsanthrene analogues that present a complex combination of donor-acceptor interactions including pnictogen-pnictogen, pnictogen-π, and pnictogen-chalcogen. We show that, in these crystals, the chalcogen-pnictogen interaction dominates over the pnictogen-pnictogen and pnictogen-π. In the latter, the role of donor and acceptor is reversed depending on the interacting moieties. Multiple chalcogen-pnictogen interactions necessitate larger donor atoms, such as sulfur. These observations explain and rationalize the experimentally observed crystal structures.
The title compound, C12H11N3O2, is a second monoclinic polymorph (P21, with Z' = 4) of the previously reported monoclinic (P21/c, with Z' = 2) form [Akhmad Aznan et al. (2010 ▶). Acta Cryst. E66, o2400]. Four independent mol-ecules comprise the asymmetric unit, which have the common features of a syn disposition of the pyridine N atom and the toluene ring, and an intra-molecular amine-nitro N-H⋯O hydrogen bond. The differences between mol-ecules relate to the dihedral angles between the rings which range from 2.92 (19) to 26.24 (19)°. The geometry-optimized structure [B3LYP level of theory and 6-311 g+(d,p) basis set] has the same features except that the entire mol-ecule is planar. In the crystal, the three-dimensional architecture is consolidated by a combination of C-H⋯O, C-H⋯π, nitro-N-O⋯π and π-π inter-actions [inter-centroid distances = 3.649 (2)-3.916 (2) Å].
The 1:1 co-crystallization of 1,4-di-aza-bicyclo-[2.2.2]octane (DABCO) with 4-nitro-benzoic acid in ethanol-water (3/1) gave the salt dihydrate C6H13N2 (+)·C7H4NO4 (-)·2H2O, (1), whereas from methanol, the salt C6H14N2 (2+)·2C7H4NO4 (-), (2), was isolated. In (1), the cation and anion are linked by a strong N-H⋯O hydrogen bond, and the carboxyl-ate anion is close to planar [dihedral angle between terminal residues = 6.83 (9)°]. In (2), a three-ion aggregate is assembled by two N-H⋯O hydrogen bonds, and the carboxyl-ate anions are again close to planar [dihedral angles between terminal residues = 1.7 (3) and 5.9 (3)°]. Through the inter-vention of solvent water mol-ecules, which self-assemble into helical supra-molecular chains along the b axis, the three-dimensional architecture in (1) is stabilized by water-DABCO O-H⋯N and water-carboxyl-ate O-H⋯O hydrogen bonds, with additional stability afforded by C-H⋯O inter-actions. The global crystal structure comprises alternating layers of water mol-ecules and ion pairs stacked along the c axis. In the crystal of (2), the three-ion aggregates are assembled into a three-dimensional architecture by a large number of methyl-ene-carboxyl-ate/nitro C-H⋯O inter-actions as well as π-π contacts between inversion-related benzene rings [inter-centroid distances = 3.5644 (16) and 3.6527 (16) Å]. The cations and anions assemble into alternating layers along the c axis.
The title complex, [Cu{μ3-O2CC6H3(NO2)2-3,5}(μ-OH)] n , features zigzag chains in which successive pairs of Cu(II) atoms are connected by OH bridges and bidentate carboxyl-ate ligands, leading to six-membered Cu(O)(OCO)Cu rings. The zigzag chains are connected into a three-dimensional architecture by Cu-O(nitro) bonds. The coordination geometry of the Cu(II) atom is square-pyramidal, with the axial position occupied by the nitro O atom, which forms the longer Cu-O bond. Bifurcated hy-droxy-nitro O-H⋯O hydrogen bonds contribute to the stability of the crystal structure.
The asymmetric unit of the title cyclic thio-urea derivative, C10H12N2S, comprises two mol-ecules, each of which has a twist about the CH2-CH2 bond within the five-membered ring. The major difference between the independent mol-ecules is manifested in the relative orientations of the five- and six-membered rings [dihedral angles between the least-squares planes = 28.03 (11) and 41.54 (11)°]. A network of C-H⋯π inter-actions consolidates the three-dimensional crystal packing.
The title dimethyl sulfoxide solvate, [Hg2(C12H9ClN2)I2]·C2H6OS, features tetra-hedrally and linearly coordinated Hg(II) atoms. The distorted tetrahedral coordination sphere is defined by chelating N atoms that define an acute angle [69.6 (3)°] and two I atoms that form a wide angle [142.80 (4)°]. The linearly coordinated Hg(II) atom [177.0 (4)°] exists with a donor set defined by C and Cl atoms. Secondary inter-actions are apparent in the crystal packing with the tetra-hedrally and linearly coordinated Hg(II) atoms expanding their coordination environments by forming weak Hg⋯I [3.772 (7) Å] and Hg⋯O [2.921 (12) Å] inter-actions, respectively. Mercury-containing mol-ecules stack along the a axis, are connected by π-π inter-actions [inter-centroid distance between pyridine and benzene rings = 3.772 (7) Å] and define channels in which the dimethyl sulfoxide mol-ecules reside. The latter are connected by the aforementioned Hg⋯O inter-actions as well as C-H⋯I and C-H⋯O inter-actions, resulting in a three-dimensional architecture.
The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O2)2], is generated by the application of a centre of inversion. The Cd-I bond lengths of the central core are close and uniformly longer than the exocyclic Cd-I bond. The coordination sphere of the Cd(II) atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-yl-methyl-idene)amino]-benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C-H⋯O and C-H⋯π inter-actions, each involving the pyridine ring.
Three independent mol-ecules of the title estrone derivative and a mol-ecule of methanol comprise the asymmetric unit of the title compound [systematic name: 13-methyl-6,7,8,9,11,12,13,14,15,16-deca-hydro-cyclo-penta-[a]phenanthren-3-ol-meth-an-ol (3/1)], 3C(18)H(24)O·CH(3)OH. Two of the estrone mol-ecules exhibit 50:50 disorder (one displays whole-mol-ecule disorder and the other partial disorder in the fused five- and six-membered rings) so that five (partial) mol-ecular conformations are discernable. The conformation of the six-membered ring abutting the aromatic ring is close to a half-chair in all five components. The conformation of the six-membered ring fused to the five-membered ring is based on a chair with varying degrees of distortion ranging from minor to significant. Two distinct conformations are found for the five-membered ring: in four mol-ecules, the five-membered ring is twisted about the bond linking it to the six-membered ring, and in the other, the five-membered ring is an envelope with the quaternary C atom being the flap atom. The crystal packing features O-H⋯O hydrogen bonding whereby the four mol-ecules comprising the asymmetric unit are linked into a supra-molecular chain along the b axis.
Two independent mol-ecules comprise the asymmetric unit of the title cholestane derivative, C(29)H(49)NO(3) {systematic name: (3S,8S,9S,10R,13R,14S,17R)-17-[(1R)-1,5-dimethyl-hex-yl]-6-hy-droxy-imino-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetra-deca-hydro-1H-cyclo-penta-[a]phenanthren-3-yl ace-tate}. The major differences between the mol-ecules relate to the relative orientations of the terminal acetyl [C-C-O-C torsion angles = -158.8 (3) and -81.7 (3)°] and alkyl groups [C-C-C-C = 168.9 (3) and 65.8 (4)°]. In the crystal, the independent mol-ecules associate via pairs of O-H⋯N hydrogen bonds, forming dimeric aggregates. Supra-molecular layers in the ab plane are mediated by C-H⋯O inter-actions.
Two independent mol-ecules comprise the asymmetric unit in the title compound, C(11)H(11)N(3). These differ in terms of the relative orientations of the aromatic rings: the first is somewhat twisted, while the second is approximately planar [dihedral angles between the pyrimidine and phenyl rings = 39.00 (8) and 4.59 (11)°]. The mol-ecules also form distinct patterns in their hydrogen bonding. The first independent mol-ecule forms centrosymmetric dimers featuring an eight-membered {HNCN}(2) synthon. The second independent mol-ecule forms an N-H⋯N hydrogen bond with the other pyrimidine N atom of the first mol-ecule. Thereby, tetra-meric aggregates are formed. These associate via C-H⋯N and C-H⋯π inter-actions, consolidating the crystal packing.
In the title cholestane derivative, C(28)H(48) [systematic name: (1S,2S,7R,10R,11R,14R,15R)-2,5,10,15-tetra-methyl-14-[(2R)-6-methyl-heptan-2-yl]tetra-cyclo-[8.7.0.0(2,7).0(11,15)]hepta-dec-4-ene], the cyclo-hexene ring adopts a half-chair conformation. The parent 5α-cholest-2-ene and the equivalent fragment of the title compound are almost superimposable (r.m.s. deviation = 0.033 Å).
The asymmetric unit of the title compound {systematic name: (3S,8S,9S,10R,13R,14S,17R)-17-[(E,2R,5S)-5-ethyl-6-methyl-hept-3-en-2-yl]-10,13-dimethyl-2,3,4,7,8,9,11,12,14,15,16,17-dodeca-hydro-1H-cyclo-penta-[a]phenanthren-3-yl p-toluene-sulfonate}, C(36)H(54)O(3)S, comprises two independent mol-ecules that differ significantly in terms of the relative orientations of the peripheral groups; the conformation about the C=C bond of the side chain is E. In the crystal, mol-ecules associate into linear supra-molecular chains aligned along the a axis via C-H⋯O inter-actions.
The title complex, [Cu(C(7)H(3)N(2)O(6))(2)(C(10)H(8)N(2))(H(2)O)]·C(4)H(8)O, features a penta-coordinate Cu(II) atom bound by two monodentate carboxyl-ate ligands, a bidentate 2,2'-bipyridine mol-ecule [dihedral angle between pyridine rings = 5.0 (2)°] and a water mol-ecule. The resulting N(2)O(3) donor set defines a distorted square-pyramidal geometry with the coordinated water mol-ecule in the apical position. In the crystal, the presence of O-H(w)⋯O(c) (w = water and c = carbon-yl) hydrogen bonding leads to the formation of a supra-molecular chain propagating along the c axis, which associates into a double chain via C-H⋯ O and π-π contacts between pyridyl rings [centroid-centroid distance = 3.527 (3) Å]. The solvent mol-ecules, which are disordered over two orientations in a 0.678 (11):0.322 (11) ratio, occupy voids defined by the complex mol-ecules and are held in place via C-H⋯O inter-actions.
The crystal and mol-ecular structures of the title salt, C8H8N3S2 (+)·Cl(-), (I), and salt hydrate, C8H7ClN3S2 (+)·Cl(-)·H2O, (II), are described. The heterocyclic ring in (I) is statistically planar and forms a dihedral angle of 9.05 (12)° with the pendant phenyl ring. The comparable angle in (II) is 15.60 (12)°, indicating a greater twist in this cation. An evaluation of the bond lengths in the H2N-C-N-C-N sequence of each cation indicates significant delocalization of π-electron density over these atoms. The common feature of the crystal packing in (I) and (II) is the formation of charge-assisted amino-N-H⋯Cl(-) hydrogen bonds, leading to helical chains in (I) and zigzag chains in (II). In (I), these are linked by chains mediated by charge-assisted iminium-N(+)-H⋯Cl(-) hydrogen bonds into a three-dimensional architecture. In (II), the chains are linked into a layer by charge-assisted water-O-H⋯Cl(-) and water-O-H⋯O(water) hydrogen bonds with charge-assisted iminium-N(+)-H⋯O(water) hydrogen bonds providing the connections between the layers to generate the three-dimensional packing. In (II), the chloride anion and water mol-ecules are resolved into two proximate sites with the major component being present with a site occupancy factor of 0.9327 (18).
In the title complex salt, [Au2{(C6H5)2PCH2P(C6H5)2}]Cl2·(CH3)2C=O·H2O, the dication forms an eight-membered {-PCPAu}2 ring with a transannular aurophilic inter-action [Au⋯Au = 2.9743 (2) Å]. The ring approximates a flattened boat conformation, with the two methyl-ene C atoms lying ca 0.58-0.59 Å above the least-squares plane defined by the Au2P4 atoms (r.m.s. deviation = 0.0849 Å). One Cl(-) anion functions as a weak bridge between the Au(I) atoms [Au⋯Cl = 2.9492 (13) and 2.9776 (12) Å]. The second Cl(-) anion forms two (water)O-H⋯Cl hydrogen bonds about a centre of inversion, forming a centrosymmetric eight-membered {⋯HOH⋯Cl}2 supra-molecular square. Globally, the dications and loosely associated Cl(-) anions assemble into layers lying parallel to the ac plane, being connected by C-H⋯Cl,π(phen-yl) inter-actions. The supra-molecular squares and solvent acetone mol-ecules are sandwiched in the inter-layer region, being connected to the layers on either side by C-H⋯Cl,O(acetone) inter-actions.
The title compound, [Fe(C17H14PS)2], is a second monoclinic polymorph (P21/c, with Z' = 1) of the previously reported monoclinic (C2/c, with Z' = 1/2) form [Fang et al. (1995 ▸). Polyhedron, 14, 2403-2409]. In the new form, the S atoms lie to the same side of the mol-ecule with the pseudo S-P⋯P-S torsion angle being -53.09 (3)°. By contrast to this almost syn disposition, in the C2/c polymorph, the Fe atom lies on a centre of inversion so that the S atoms are strictly anti, with a pseudo-S-P⋯P-S torsion angle of 180°. The significant difference in mol-ecular conformation between the two forms does not result in major perturbations in the P=S bond lengths nor in the distorted tetra-hedral geometries about the P atoms. The crystal packing of the new monoclinic polymorph features weak Cp-C-H⋯π(phen-yl) inter-actions consolidating linear supra-molecular chains along the a axis. These pack with no directional inter-actions between them.
The Yb(III) atom in the title complex, [Yb(C27H24Cl3N4O3)] [systematic name: (2,2',2''-{(nitrilo)-tris-[ethane-2,1-di-yl(nitrilo)-methylyl-idene]}tris-(4-chloro-phenolato)ytterbium(III)], is coordinated by a trinegative, hepta-dentate ligand and exists within an N4O3 donor set, which defines a capped octa-hedral geometry whereby the amine N atom caps the triangular face defined by the three imine N atoms. The packing features supra-molecular layers that stack along the a axis, sustained by a combination of aryl-C-H⋯O, imine-C-H⋯O, methyl-ene-C-H⋯π(ar-yl) and end-on C-Cl⋯π(ar-yl) inter-actions. A Hirshfeld surface analysis points to the major contributions of C⋯H/ H⋯C and Cl⋯H/H⋯Cl inter-actions (along with H⋯H) to the overall surface but the Cl⋯H contacts are at distances greater than the sum of their van der Waals radii.
The title compound, [Au(C9H10NOS)(C18H15P)], features a near linear P-Au-S arrangement defined by phosphane P and thiol-ate S atoms with the minor distortion from the ideal [P-Au-S is 177.61 (2)°] being traced in part to the close intra-molecular approach of an O atom [Au⋯O = 3.040 (2) Å]. The packing features supra-molecular layers lying parallel to (011) sustained by a combination of C-H⋯π and π-π [inter-centroid distance = 3.8033 (17) Å] inter-actions. The mol-ecular structure and packing are compared with those determined for a previously reported hemi-methanol solvate [Kuan et al. (2008 ▸). CrystEngComm, 10, 548-564]. Relatively minor differences are noted in the conformations of the rings in the Au-containing mol-ecules. A Hirshfeld surface analysis confirms the similarity in the packing with the most notable differences relating to the formation of C-H⋯S contacts between the constituents of the solvate.
The common feature of the title compounds, [Zn(C5H10NO2S2)2(C10H8N2)]·2H2O, (I), and [Zn(C6H12NOS2)2(C10H8N2)], (II), is the location of the Zn(II) atoms on a twofold rotation axis. Further, each Zn(II) atom is chelated by two symmetry-equivalent and symmetrically coordinating di-thio-carbamate ligands and a 2,2'-bi-pyridine ligand. The resulting N2S4 coordination geometry is based on a highly distorted octa-hedron in each case. In the mol-ecular packing of (I), supra-molecular ladders mediated by O-H⋯O hydrogen bonding are found whereby the uprights are defined by {⋯HO(water)⋯HO(hy-droxy)⋯} n chains parallel to the a axis and with the rungs defined by 'Zn[S2CN(CH2CH2)2]2'. The water mol-ecules connect the ladders into a supra-molecular layer parallel to the ab plane via water-O-H⋯S and pyridyl-C-H⋯O(water) inter-actions, with the connections between layers being of the type pyridyl-C-H⋯S. In (II), supra-molecular layers parallel to the ab plane are sustained by hy-droxy-O-H⋯S hydrogen bonds with connections between layers being of the type pyridyl-C-H⋯S.