Bioactive flavanones from Luma chequen

A bioassay-guided chemical study of a methanolic extract of fresh leaves of Luma chequen led to the isolation of lumaflavanones A (1), B (2) and C (3) whose structures are proposed on the basis of NMR spectroscopic data. The structure of lumaflavanone A was confirmed by X-ray analysis. Antifeedant (Spodoptera littoralis), brine shrimp (Artemia salina) and fungistatic (Botrytis cinerea) bioassays showed that while 3 was the most active in the first two assays the mixture of 1 and 2 was more effective as a fungistatic

High-pressure phases and transitions of the layered alkaline earth nitridosilicates SrSiN2 and BaSiN2

We investigate the high-pressure phase diagram of SrSiN2 and BaSiN2 with density-functional calculation. Searching a manifold of possible candidate structures, we propose new structural modifications of SrSiN2 and BaSiN2 attainable in high-pressure experiments. The monoclinic ground state of SrSiN2 transforms at 3 GPa into an orthorhombic BaSiN2 type. At 14 GPa a CaSiN2-type structure becomes the most stable configuration of SrSiN2. A hitherto unknown Pbcm modification is adopted at 85 GPa and, finally, at 131 GPa a LiFeO2-type structure. The higher homologue BaSiN2 transforms to a CaSiN2 type at 41 GPa and further to a Pbcm modification at 105 GPa. Both systems follow the pressure-coordination rule: the coordination environment of Si increases from tetrahedral through trigonal bipyramidal to octahedral. Some high-pressure phases are related in structure through simple group–subgroup mechanisms, indicating displacive phase transformations with low activation barriers

2-Amino-6-(2,4-dichloro­phen­yl)-4-oxo-3,5-diphenyl­cyclo­hex-2-enecarbonitrile

In the title compound, C25H18Cl2N2O, the cyclo­hexene ring has a sofa conformation. All the substituents in the cyclo­hexene ring, except the cyano group (which is axial) occupy equatorial positions. The crystal structure is stabilized through N—H⋯O hydrogen bonds, forming a chain extending along the b axis and through C—H⋯N and C—H⋯Cl inter­actions. It is remarkable that only one of the amino H atoms is involved in hydrogen bonding

Methyl (2E)-2-{[(2-methyl­quinolin-8-yl)­oxy]meth­yl}-3-(thio­phen-2-yl)acrylate

In the mol­ecule of the title compound, C19H17NO3S, the dihedral angle formed by the quinoline ring system and the thio­phene ring is 83.15 (8)°. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into a C(8) chain running along the b axis. The packing of the mol­ecules is further influenced by C—H⋯π inter­actions

3′-(4-Chloro­benzo­yl)-4′-(4-chloro­phen­yl)-1′-methyl­spiro­[indoline-3,2′-pyrrolidin]-2-one

In the title compound, C25H20Cl2N2O2, the pyrrolidine ring adopts an envelope conformation and the best plane through the five ring atoms makes a dihedral angle of 87.03 (8)° with the indoline ring. Mol­ecules are connected by pairs of N—H⋯O hydrogen bonds into centrosymmetric dimers with an R 2 2(8) graph-set ring motif. C—H⋯O hydrogen bonds stabilize the crystal structure

Diaqua­dichloridobis(pyridine-κN)manganese(II)

The molecular title compound, [MnCl2(C5H5N)2(H2O)2], lies about an inversion centre. The MnII atom is in an all-trans octa­hedral environment defined by two water mol­ecules, two chloride anions and two pyridine ligands. An inter­molecular hydrogen-bonding inter­action between a water mol­ecule and a chloride anion bonded to an adjacent MnII atom generates an eight-membered ring. The crystal packing exhibits two inter­molecular π–π stacking inter­actions between the aromatic rings, with centroid–centroid distances of 3.485 (12) and 3.532 (12) Å

5-Methyl-12-phenyl­sulfonyl-12H-naphtho­[1,2-b]carbazole

In the title compound, C27H19NO2S, the naphtho­carbazole unit is approximately planar (r.m.s. deviation = 0.002 Å) except for the N atom, which is displaced by 0.122 (1) Å out of the mean plane. The dihedral angle between the naphtho­carbazole mean plane and the phenyl ring of the phenyl­sulfonyl substituent is 83.16 (3)°. An inter­molecular C—H⋯π inter­action involving the phenyl group and the pyrrole ring is observed in the crystal structure

5-Methyl­phenanthro[2,3-b]thio­phene

The title compound, C17H12S, which crystallises with two molecules in the asymmetric unit, features four fused rings forming an essentially planar mol­ecule, with maximum deviations from the mean plane of 0.078 (2) and 0.080 (2) Å for C atoms of the thio­phene and phenanthrene groups in both the mol­ecules. The crystal packing features weak C—H⋯π inter­actions

1-[(Biphenyl-4-yl)(phen­yl)meth­yl]-1H-imidazole (bifonazole)

In the title compound, C22H18N2, the dihedral angles formed by the imidazole ring with the phenyl ring and the benzene ring of the biphenyl group are 87.02 (5) and 78.20 (4)°, respectively. In the crystal, mol­ecules inter­act through inter­molecular C—H⋯N hydrogen bonds, forming chains parallel to the b axis. These chains are further linked into a three-dimensional network by C—H⋯π stacking inter­action

2-[4-(Methyl­sulfan­yl)phen­yl]naphtho[1,8-de][1,3,2]diaza­borinane

The title compound, C17H15BN2S, is one member in a series of diaza­borinanes featuring substitution at the 1-, 2- and 3-positions in the nitro­gen–boron heterocycle. The dihedral angle between the mean planes of the naphthalene and phenyl ring systems is 19.86 (6)°. In the crystal structure, two C—H⋯π inter­actions link the mol­ecules into sheets which lie parallel to the bc plane. There is a π–π inter­action between each pair of centrosymmetrically related sheets [centroid–centroid distance = 3.5922 (8) Å]