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.

Photoelectrical Dynamics Uplift in Perovskite Solar Cells by Atoms Thick 2D TiS2 Layer Passivation of TiO2 Nanograss Electron Transport Layer.

A deficiency in the photoelectrical dynamics at the interface due to the surface traps of the TiO2 electron transport layer (ETL) has been the critical factor for the inferiority of the power conversion efficiency (PCE) in the perovskite solar cells. Despite its excellent energy level alignment with most perovskite materials, its large density of surface defect as a result of sub lattice vacancies has been the critical hurdle for an efficient photovoltaic process in the device. Here, we report that atoms thick 2D TiS2 layer grown on the surface of a (001) faceted and single-crystalline TiO2 nanograss (NG) ETL have effectively passivated the defects, boosting the charge extractability, carrier mobility, external quantum efficiency, and the device stability. These properties allow the perovskite solar cells (PSCs) to produce a PCE as high as 18.73% with short-circuit current density (Jsc), open-circuit voltage (Voc), and fill-factor (FF) values as high as 22.04 mA/cm2, 1.13 V, and 0.752, respectively, a 3.3% improvement from the pristine TiO2-NG-based PSCs. The present approach should find an extensive application for controlling the photoelectrical dynamic deficiency in perovskite solar cells.

A two-dimensional crystal growth in anatase titania nanostructures driven by trigonal hydronium ions.

Two-dimensional growth or high-energy faceting during a wet-chemical nanocrystal growth involves a dynamic surfactant functionalization that selectively allows a particular crystal plane to grow and simultaneously, passivates others from evolving. Here, by simply controlling the concentration of hydronium ions in a liquid-phase deposition reaction, the two-dimensional growth of a few atoms thick and (001) facet in anatase titania nanostructures can be achieved. The morphology can be modified from nanocube to nanobelt and nanosheet by increasing the hydronium ion concentration. Raman analysis reveals that the trigonal hydronium ions attach to the growing planes of anatase TiO2 via a dative bonding, projecting atom-thick and large-scale (001) faceted nanobelts and nanosheets.

Crystal structure of bis-(aceto-phenone 4-benzoyl-thio-semicarbazonato-κ(2) N (1),S)nickel(II).

In the asymmetric unit of the title complex, [Ni(C16H14N3OS)2], the nickel ion is tetra-coordinated in a distorted square-planar geometry by two independent mol-ecules of the ligand which act as mononegative bidentate N,S-donors and form two five-membered chelate rings. The ligands are in trans (E) conformations with respect to the C=N bonds. The close approach of hydrogen atoms to the Ni(2+) atom suggests anagostic inter-actions (Ni⋯H-C) are present. The crystal structure is built up by a network of two C-H⋯O inter-actions. One of the inter-actions forms inversion dimers and the other links the mol-ecules into infinite chains parallel to [100]. In addition, a weak C-H⋯π inter-action is also present.

Synthesis, spectral characterization and crystals structure of some arsane derivatives of gold (I) complexes: a comparative density functional theory study.

A series of complexes of the type LAuCl where L = tris(p-tolylarsane), tris(m-tolylarsane), bis(diphenylarsano)ethane, and tris(naphthyl)arsane have been synthesized. All of the new complexes, 1-4, have been fully characterized by means of ¹H NMR and ¹³C NMR spectroscopy and single crystal X-ray crystallography. The structures of complexes 1-4 have been determined from X-ray diffraction data. The linear molecules have an average bond distance between gold-arsenic and gold-chlorine of 2.3390Å and 2.2846Å, respectively. Aurophilic interaction was prominent in complex 1 and 3, whereas complex 2 and 4 do not show any such interaction. The intermolecular gold interaction bond length was affected by the electronegativity of the molecule. The computed values calculated at DFT level using B3LYP function are in good agreement with the experimental results.

Crystal structures of 3,5-bis-[(E)-3-hy-droxy-benzyl-idene]-1-methyl-piperidin-4-one and 3,5-bis-[(E)-2-chloro-benzyl-idene]-1-methyl-piperidin-4-one.

The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hy-droxy-benzyl-idene and 2-chloro-benzyl-idene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis-(4-hy-droxy-3-meth-oxy-phen-yl)-1,6-hepta-diene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, forming chains along [10-1]. The chains are linked via C-H⋯O hydrogen bonds, forming undulating sheets parallel to the ac plane. In the crystal of (2), mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along the a-axis direction by π-π inter-actions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).

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.

An efficient ionic liquid mediated synthesis, cholinesterase inhibitory activity and molecular modeling study of novel piperidone embedded α,ß-unsaturated ketones.

A series of hitherto unreported piperidone embedded α,ß-unsaturated ketones were synthesized efficiently in ionic solvent and evaluated for cholinesterase inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Most of the synthesized compounds displayed good enzyme inhibition; therein compounds 7i and 7f displayed significant activity against AChE with IC50 values of 1.47 and 1.74 µM, respectively. Compound 6g showed the highest BChE inhibitory potency with IC50 value of 3.41 µM, being 5 times more potent than galanthamine. Molecular modeling simulation was performed using AChE and BChE receptors extracted from crystal structure of human AChE and human BChE to determine the amino acid residues involved in the binding interaction of synthesized compounds and their relevant receptors.

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).

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-[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.

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.

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.

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.

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,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.

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.

(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.