Crystal structure of bromido-bis-(naph-thal-en-1-yl)anti-mony(III).

In the title compound, [SbBr(C10H7)2], the Sb(III) atom has a distorted trigonal-pyramidal coordination geometry and the planes of the two naphthalene ring systems make a dihedral angle of 80.26 (18)°. An intra-molecular C-H⋯Br hydrogen bond forms an S(5) ring motif. In the crystal, weak C-H⋯Br inter-actions link the mol-ecules into helical chains along the b-axis direction.

(Benzyl-diphenyl-phosphane-1κP)[µ-bis(diphenylphosphan-yl)methane-2:3κ(2) P:P']nona-carbonyl-1κ(3) C,2κ(3) C,3κ(3) C-triangulo-triruthenium(0).

The asymmetric unit of the title compound, [Ru3(C19H17P)(C25H22P2)(CO)9], consists of two independent mol-ecules. The bis-(di-phenyl-phosphan-yl)methane ligand bridges an Ru-Ru bond and the benzyl-diphenyl-phosphane ligand binds to the third Ru atom. The Ru-Ru bond cis to the benzyl-diphenyl-phosphane ligand is the longest of the three Ru-Ru bonds in both mol-ecules. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming layers parallel to the ac plane. C-H⋯π contacts further stabilize the crystal packing.

9-Benzyl-6-benzyl-sulfanyl-9H-purin-2-amine.

In the title compound, C19H17N5S, the dihedral angles between the purine ring system (r.m.s. deviation = 0.009 Å) and the S-bound and methyl-ene-bound phenyl rings are 74.67 (8) and 71.28 (7)°, respectively. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(8) loops. C-H⋯N inter-actions link the dimers into (100) sheets.

Supramolecular architectures of N-acetyl-L-proline monohydrate and N-benzyl-L-proline.

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...O hydrogen bonds and the other by an R4(4)(23) ring through C-H...O interactions. In (II), the crystal packing interactions consist of N-H...O and C-H...O hydrogen bonds. Proline (Pro) exists in its neutral form in (I) and is zwitterionic in (II). This difference in the ionization states of Pro is manifested through the absence of N-H...O and presence of O-H...O interactions in (I), and the presence of N-H...O and absence of O-H...O hydrogen bonds in (II). While C-H...O interactions are present in both (I) and (II), the geometry of the synthons formed by them and their mode of participation in intermolecular interactions is different. Though the title compounds differ significantly in terms of modifications in the Pro skeleton, the differences in their supramolecular structures may also be viewed as a result of the molecular recognition facilitated by the presence of a solvent water molecule in (I) and the zwitterionic state of the amino acid in (II).

3-{5-Eth-oxy-carbonyl-1-[3-(2-oxopyrrol-idin-1-yl)prop-yl]-1H-benzimidazol-2-yl}benzoic acid.

In the title compound, C(24)H(25)N(3)O(5), the eth-oxy group is disordered over two orientations in a 0.853 (14):0.147 (14) ratio. The benzimadazole ring system (r.m.s. deviation = 0.016 Å) makes a dihedral angle of 35.47 (7)° with the attached benzene ring. The pyrrolidine ring adopts an envelope conformation with a methyl-ene C atom as the flap. In the crystal, inversion dimers linked by pairs of O-H⋯N hydrogen bonds generate R(2) (2)(16) loops. C-H⋯O inter-actions link the dimers into a three-dimensional network.

N-But-oxy-carbonyl-5-oxo-l-proline ethyl ester.

The mol-ecular structure of the title compound, C12H19NO5, may be visualized as made up of two nearly perpendicular planes [dihedral angle = 87.39 (12)°] and its crystal structure is a good example of C-H⋯O inter-actions assuming significance in optimizing supra-molecular aggregation in crystals in a mol-ecule which is severely imbalanced in terms of donors to acceptor atoms. The pyrrolidine ring adopts a ((3) T 2) twist conformation with puckering parameters Q = 0.2630 (4) Šand ϕ = 59 (9)°. The crystal structure features R 2 (4)(10) and R 3 (4)(26) ring motifs formed by four weak C-H⋯O inter-actions, leading to supra-molecular sheets lying parallel to the bc plane.

N-tert-But-oxy-carbonyl-α-(2-fluoro-benzyl)-l-proline.

In the title compound, C17H22FNO4, the pyrrolidine ring adopts an envelope conformation with the disordered com-ponents of the methylene C atom, with site occupancies of 0.896 (7) and 0.104 (7), being the flap on either side of the mean plane involving the other atoms of the ring. The carb-oxy-lic acid group forms dihedral angles of 72.06 (11) and 45.44 (5)° with the N-tert-but-oxy-carbonyl group and the 2-fluoro-benzyl group, respectively. In the crystal, two-dimensional layers of mol-ecules parallel to (001) are built through an R 4 (4)(23) motif generated via O-H⋯O, C-H⋯O and C-H⋯F inter-actions, and an R 2 (2)(11) motif generated by C-H⋯O and C-H⋯F inter-actions.

Ethyl 2-[4-(di-methyl-amino)-phen-yl]-1-phenyl-1H-benzimidazole-5-carboxyl-ate.

In the title compound, C24H23N3O2, the benzimidazole ring system makes dihedral angles of 7.28 (5) and 67.17 (5)°, respectively, with the planes of the benzene and phenyl rings, which in turn make a dihedral angle of 69.77 (6)°. In the crystal, mol-ecules are connected by C-H⋯N and C-H⋯O inter-actions, forming a layer parallel to the bc plane. A π-π inter-action, with a centroid-centroid distance of 3.656 (1) Å, is observed in the layer.

4'-(4-Fluoro-phen-yl)-1'-methyl-dispiro-[indane-2,2'-pyrrolidine-3',2''-indane]-1,3,1''-trione methanol hemisolvate.

The asymmetric unit of the title compound, C29H24FNO5·0.5CH3OH, contains two independent mol-ecules and a one methanol solvent mol-ecule. The methanol mol-ecule is O-H⋯O hydrogen bonded to one of the independent mol-ecules. The pyrrolidine rings in both mol-ecules adopt half-chair conformations, while the cyclo-pentane rings within the indane groups are in flattened envelope conformations, with the spiro C atoms forming the flaps. The benzene rings of the indane ring systems form a dihedral angle of 35.06 (7)° in one independent mol-ecule and 31.16 (8)° in the other. The fluoro-substituted benzene ring forms dihedral angles of 65.35 (6) and 85.87 (7)° with the indane group benzene rings in one mol-ecule, and 72.78 (8) and 77.27 (8)° in the other. In each mol-ecule, a weak intra-molecular C-H⋯O hydrogen bond forms an S(6) ring motif. In the crystal, weak C-H⋯O, C-H⋯N and C-H⋯F hydrogen bonds link the mol-ecules into a three-dimensional network.

N,N'-Bis(phenyl-carbamo-thio-yl)benzene-1,3-dicarboxamide.

The asymmetric unit of the title compound, C22H18N4O2S2, contains two mol-ecules. In one of them, the dihedral angles between the central benzene ring and the phenyl rings are 16.97 (8) and 20.97 (8)°, while the phenyl rings make a dihedral angle of 37.87 (8)°. In the other mol-ecule, the corresponding values are 34.92 (7), 53.90 (7) and 60.68 (8)°, respectively. In each mol-ecule, two intra-molecular N-H⋯O hydrogen bonds generate S(6) rings and a short C-H⋯S contact also occurs. In the crystal, N-H⋯S, N-H⋯O, C-H⋯O and C-H⋯S inter-actions link the mol-ecules into a three-dimensional network.

Ethyl 2-[5-(4-fluoro-phen-yl)pyridin-3-yl]-1-[3-(2-oxopyrrolidin-1-yl)prop-yl]-1H-benzimidazole-5-carboxyl-ate.

In the title compound, C28H27FN4O3·H2O, the benzimidazole ring system is essentially planar with a maximum deviation of 0.028 (1) Å. It makes dihedral angles of 47.59 (5) and 60.31 (5)°, respectively, with the pyridine and benzene rings, which make a dihedral angle of 22.58 (6)° with each other. The pyrrolidine ring shows an envelope conformation with one of the methyl-ene C atoms as the flap. In the crystal, the components are connected into a tape along the b-axis direction through O-H⋯O and O-H⋯N hydrogen bonds and a π-π inter-action between the pyridine and benzene rings [centroid-centroid distance of 3.685 (8) Å]. The tapes are further linked into layers parallel to the ab plane by C-H⋯O and C-H⋯F inter-actions.

5,8-Dihy-droxy-2,2-dimethyl-12-(3-methyl-but-2-en-yl)pyrano[3,2-b]xanthen-6-one (brasixanthone B).

The title compound (trivial name brasixanthone B), C23H22O5, isolated from Calophyllum gracilentum, is characterized by a xanthone skeleton of three fused six-membered rings plus an additional fused pyrano ring and one 3-methyl-but-2-enyl side chain. The core xanthone moiety is almost planar, with a maximum deviation 0.057 (4) Šfrom the mean plane. In the mol-ecule, an intra-molecular O-H⋯O hydrogen bond forms an S(6) ring motif. The crystal structure features inter-molecular O-H⋯O and C-H⋯O inter-actions.

Supramolecular sheets in (4H-chromeno[4,3-c]isoxazol-3-yl)methanol and its hydrated 8-methyl-substituted analogue at 100 K.

The title compounds, (4H-chromeno[4,3-c]isoxazol-3-yl)methanol, C(11)H(9)NO(3), (I), and (8-methyl-4H-chromeno[4,3-c]isoxazol-3-yl)methanol monohydrate, C(12)H(11)NO(3)·H(2)O, (II), crystallize in the monoclinic space groups P2(1)/c and C2/c, respectively. The simple addition of a methyl substituent in (II) results in a change in the structure type and substantially alters the intermolecular interaction patterns, while retaining the point-group symmetry 2/m. Compound (II) crystallizes as a hydrate and the resulting hydrogen-bonding interactions involving the water molecule are the cause of differences in the hydrogen-bonded supramolecular motifs present in (I) and (II). The water molecule in (II) is disordered over two positions having very similar orientations, with occupancies of 0.571 (18) and 0.429 (18), although the pattern of hydrogen-bonding interactions for the two disordered water molecules remains essentially the same. In both compounds, the primary donor hydroxy group adopts a trans conformation with respect to the isoxazole O atom, with a torsion angle of 170.65 (8)° for (I) and 179.56 (10)° for (II), the small difference being due to differences in the hydrogen-bonding environment of the hydroxy group. In (I), molecules are linked through two independent O-H···N and C-H···O hydrogen bonds and form sheets of centrosymmetric R(4)(4)(18) and R(4)(4)(14) rings extending parallel to the (100) plane. The supramolecular motifs in (II) generate two-dimensional sheets parallel to the (100) plane through a combination of O-H···X (X = N, O) and C-H···O hydrogen bonds, leading to water-assisted noncentrosymmetric R(2)(2)(8) and R(6)(6)(20) motifs. The present work is an example of how the simple replacement of a substituent in the main molecular scaffold may transform the structure type, paving the way for a variety of supramolecular motifs and consequently altering the complexity of the intermolecular interaction patterns.

Supramolecular networks in (9-fluoro-4H-chromeno[4,3-c]isoxazol-3-yl)methanol and its 9-chloro analogue at 100 K.

The title compounds, (9-fluoro-4H-chromeno[4,3-c]isoxazol-3-yl)methanol, C(11)H(8)FNO(3), (I), and (9-chloro-4H-chromeno[4,3-c]isoxazol-3-yl)methanol, C(11)H(8)ClNO(3), (II), crystallize in the orthorhombic space group Pbca with Z' = 1 and the triclinic space group P-1 with Z' = 6, respectively. The simple replacement of F by Cl in the main molecular scaffold of (I) and (II) results in significant differences in the intermolecular interaction patterns and a corresponding change in the point-group symmetry from D(2h) to C(i) = S(2). These striking differences are manifested through the presence of C-H···F and the absence of O-H···O and C-H···O interactions in (I), and the absence of C-H···Cl and the presence of O-H···O and C-H···O interactions in (II). However, the geometry of the synthons formed by the O-H···N and O-H···X (X = F or Cl) interactions observed in the constitution of the supramolecular networks of both (I) and (II) remains similar. Also, C-H···O interactions are not preferred in the presence of F in (I), while they are much preferred in the presence of Cl in (II).

Bromido({2-[2-(diphenyl-phosphan-yl)benzyl-idene]hydrazin-1-yl-idene}(4-meth-oxy-anilino)methane-thiol-ato)palladium(II) acetone monosolvate.

In the title compound, [PdBr(C(27)H(23)N(3)OPS)]·C(3)H(6)O, the coordination geometry about the Pd(II) atom is distorted square-planar, arising from the attached Br, S, P and N atoms (N and Br are trans), the maximum deviation from the plane being 0.2053 (4) Šfor the N atom. The three benzene rings attached to the P atom make dihedral angles of 69.78 (7), 87.05 (7) and 77.50 (7)° with each other. An intra-molecular C-H⋯N hydrogen bond forms an S(6) ring motif. In the crystal, the complex mol-ecules form infinite chains along the a-axis direction through C-H⋯Br inter-actions, and a C-H⋯O inter-action links the main mol-ecule with the acetone solvent mol-ecule.

2-Cyano-N'-[(E)-1-(2-oxo-2H-chromen-3-yl)ethyl-idene]acetohydrazide.

In the title compound, C(14)H(11)N(3)O(3), the chromene ring is almost planar, with a maximum deviation of 0.065 (2) Šfrom the mean plane for one of the C atoms. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R(2) (2)(8) loops. The dimers are linked by C-H⋯N and C-H⋯O inter-actions into a three-dimensional network. An aromatic π-π stacking inter-action, with a centroid-centroid distance of 3.562 (10) Å, is also observed.

Bis(6-meth-oxy-1-methyl-2,3,4,9-tetra-hydro-1H-ß-carbolin-2-ium) tetra-chloridozincate(II) dihydrate.

The asymmetric unit of the title compound, (C(13)H(17)N(2)O)(2)[ZnCl(4)]·2H(2)O, contains two tetra-hydro-harmine cations, one tetra-chloro-zincate(II) anion and two water mol-ecules. In the cations, the two 1H-indole ring systems are essentially planar, with maximum deviations of 0.016 (2) and 0.018 (2) Å, and both tetra-hydro-pyridinium rings show a half-chair conformation. The Zn(II) complex anion has a distorted tetra-hedral geometry. In the crystal, inter-molecular N-H⋯O, N-H⋯Cl, O-H⋯O, O-H⋯Cl and C-H⋯O hydrogen bonds link the components into a three-dimensional network. A π-π inter-action with a centroid-centroid distance of 3.542 (14) Šis also observed.

{5,5'-Dimeth-oxy-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}palladium(II).

In the title compound, [Pd(C(21)H(24)N(2)O(4))], the complete mol-ecule is generated by crystallographic mirror symmetry with the Pd and three C atoms lying on the mirror plane. The Pd-O and Pd-N distances are 1.9932 (6) and 2.0029 (7) Å, respectively. The dihedral angle between two benzene rings of the ligand is 79.21 (4)°. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the ab plane. These planes are further connected by C-H⋯O inter-actions, forming a three-dimensional network.

6-Meth-oxy-1-(4-meth-oxy-phen-yl)-1,2,3,4-tetra-hydro-9H-ß-carbolin-2-ium acetate.

In the title compound, C(19)H(21)N(2)O(2) (+)·C(2)H(3)O(2) (-), the 1H-indole ring system is essentially planar [maximum deviation = 0.0257 (14) Å] and forms a dihedral angle of 87.92 (7) Šwith the benzene ring attached to the tetra-hydro-pyridinium fragment. The tetra-hydro-pyridinium ring adopts a half-chair conformation. In the crystal, cations and anions are linked by inter-ionic N-H⋯O, C-H⋯O and C-H⋯N hydrogen bonds into chains along the a axis.

(3'R)-3'-Benzyl-2',3'-dihydro-1H-spiro-[indole-3,1'-naphtho-[2,3-c]pyrrole]-2,4',9'-trione.

In the title compound, C(26)H(18)N(2)O(3), the maximum deviations from planarity for the tetra-hydro-1H-naphtho-[2,3-c]pyrrole and indoline rings systems are 0.091 (1) and 0.012 (2) Å, respectively. These ring systems make a dihedral angle of 89.95 (6)° with each other and they make dihedral angles of 73.42 (8) and 71.28 (9)°, respectively, with the benzene ring. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R(2) (2)(8) loops and C-H⋯O inter-actions connect the dimers into corrugated sheets lying parallel to the bc plane.