Phenanthrene System Research Articles

Photochemical Unmasking of Polyyne Rotaxanes.

Bulky photolabile masked alkyne equivalents (MAEs) are needed for the synthesis of polyyne polyrotaxanes, as insulated molecular wires and as stabilized forms of the linear polymeric allotrope of carbon, carbyne. We have synthesized a novel MAE based on phenanthrene and compared it with an indane-based MAE. Photochemical unmasking of model compounds was studied at different wavelengths (250 and 350 nm), and key products were identified by NMR spectroscopy and X-ray crystallography. UV irradiation at 250 nm leads to unmasking of both MAEs. Irradiation of the phenanthrene system at 350 nm results in quantitative dimerization via [2 + 2] cycloaddition to form a [3]-ladderane; irradiation of this ladderane at 250 nm generates a dihydrotriphenylene, which can be oxidized easily to a triphenylene. Irradiation of the indane-based MAE at 350 nm in the presence of traces of oxygen forms an endoperoxide and a bisepoxide. Both MAEs have been incorporated into rotaxanes via copper-mediated active metal template Glaser or Cadiot-Chodkiewicz coupling. The identity of the rotaxanes was confirmed by NMR spectroscopy and mass spectrometry. The phenanthrene rotaxane decomposes during attempted photochemical unmasking, whereas photolysis of the indane rotaxane results in unmasking of the polyyne thread to form a rotaxane with a chain of 16 sp-hybridized carbon atoms. This approach opens avenues toward the synthesis of encapsulated carbon allotropes.

Crystal structure of 4,5-di-bromo-phenanthrene.

The synthesis and crystal structure of the title compound, C14H8Br2, is described. The mol-ecule is positioned on a twofold rotation axis and the asymmetric unit consists of half a mol-ecule with the other half being generated by symmetry. The presence of two large bromine atoms in the bay region significantly distorts the mol-ecule from planarity and the mean planes of the two terminal rings of the phenanthrene system are twisted away from each other by 28.51 (14)°. The torsion angle between the two C-Br bonds is 74.70 (14)° and the distance between the two Br atoms is 3.2777 (13) Å. The mol-ecules pack in layers in the crystal, with the centroids of the central rings of the phenanthrene units in adjacent layers separated by a distance of 4.0287 (10) Å. These centroids are shifted by 2.266 (6) Å relative to each other, indicating slippage in the stacking arrangement. Furthermore, the distance between the centroids of the terminal and central rings of the phenanthrene units in adjacent layers is slightly shorter at 3.7533 (19) Å. While all of the mol-ecules within each layer are oriented in the same direction, those in adjacent layers are oriented in the opposite direction, leading to anti-parallel stacks.

2-(5-Bromothiophen-2-yl)-1-phenyl-1H-phenanthro[9,10-d]imidazole

In the title molecule, C25H15BrN2S, the phenanthrene system is slightly skewed, with a dihedral angle of 8.94 (16)° between the outer benzene rings. The imidazole ring makes dihedral angles of 15.18 (16), 2.94 (15) and 88.46 (16)°, respectively, with the thiophene ring, the central benzene ring of the phenanthrene unit and the phenyl ring attached to the latter unit. In the molecule, there are two C—H...π interactions present involving the phenyl ring. In the crystal, molecules are linked by C—H...N and C—H...Br hydrogen bonds, forming zigzag chains along the a axis. The chains are linked by C—H...π interactions, forming a three-dimensional supramolecular structure.

Difference in optical properties of anthracene molecule aggregates in fluorene and phenanthrene crystals

AbstractOptical properties of anthracene molecules in phenanthrene crystals with anthracene concentration of 0.03% to 8.4% were investigated and compared with those in fluorene crystals. In contrast to fluorene system where two kinds of dimers, one of which is accompanied by lattice relaxation, are observed, it was found that only one kind of dimers without lattice relaxation are observed in phenanthrene system. Also in aggregates of anthracene in higher concentration samples, the luminescence is a ‘free exciton’‐type in phenanthrene crystals in contrast to a ‘self‐trapped exciton’‐type in fluorene crystals. With reference to the variation of the magnitude of exciton–phonon coupling constant on nearest neighbour distance of molecules known for bulk crystals of aromatic molecules, the difference is attributed to longer inter molecular distance between anthracene molecules in phenanthrene matrix in comparison to those in fluorene matrix (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Synthesis of novel conjugated polymer based on cyclopenta[def]phenanthrene and vinylene with strong interchain interaction

AbstractIn this study, a novel conjugated polymer, poly(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[def]phenanthrene‐2,6‐vinylene) (PCPPV) has been synthesized and characterized. For the polymerization, Gilch's reaction was applied for the first time with the cyclopenta[def]phenanthrene system. The absorption and emission spectra of PCPPV are red‐shifted about 40–50 nm due to the vinylene units when compared with those of poly(2,6‐(4,4‐bis(2‐ethylhex‐yl)‐4H‐cyclopenta[def]phenanthrene)) (PCPP). The solid‐state fluorescence is significantly broadened, possibly due to π–π interactions introduced by the phenanthrene and vinylene moieties. In solution, as the concentration of polar solvent increased, the photoluminescence (PL) intensity decreased due to quenching and aggregation by the interchain interactions between the conjugated backbones. After annealing the film at 80 °C, the PL and electroluminescence (EL) emission spectra exhibited also the quenching and aggregation effects indicating the interchain interactions of PCPPV. The large number of aromatic rings in a unit and the increased planarity achieved through introduction of vinylene units are able to give interchain interactions stronger than fluorene or phenylene units. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5068–5077, 2009

Anaerobic biotransformation of fluorene and phenanthrene by sulfate-reducing bacteria and identification of biotransformation pathway

In the present study, anaerobic biotransformation of fluorene and phenanthrene by sulfate-reducing bacteria (SRB) was investigated and biotransformation pathways were proposed. SRB was enriched from anaerobic swine wastewater sludge and its abundance was determined by the fluorescence in situ hybridization (FISH) technique. Batch anaerobic biotransformation studies were conducted with fluorene (5 mg L −1), phenanthrene (5 mg L −1) and a mixture of the two (10 mg L −1). After 21 d of incubation, 88% of fluorene and 65% of phenanthrene were biotransformed by SRB. In contrast to previous studies, a decrease in biotransformation efficiency was observed in the presence of both fluorene and phenanthrene. Throughout the study, sulfate reduction was coupled with biotransformation of fluorene and phenanthrene. However, no increase in bacterial cell density was observed in the presence of an inhibitor, i.e. molybdate. Identification of metabolites by gas chromatography–mass spectrometry (GC–MS) revealed that fluorene and phenanthrene were biotransformed through a sequence of hydration and hydrolysis reactions followed by decarboxylation with the formation of p-cresol (only in the phenanthrene system) and phenol. The metabolites identified suggest novel biotransformation pathways of fluorene and phenenthrene.

Synthesis and biological evaluation of novel 5( H)-phenanthridin-6-ones, 5( H)-phenanthridin-6-one diketo acid, and polycyclic aromatic diketo acid analogs as new HIV-1 integrase inhibitors

A new series of phenanthridinone derivatives, and diketo acid analogs, as well as related phenanthrene and anthracene diketo acids have been synthesized and evaluated as HIV integrase (IN) inhibitors. Several new β-diketo acid analogs with the phenanthridinone scaffold replaced by phenanthrene, anthracene or pyrene exhibited the highest IN inhibitory potency. There is a general selectivity against the integrase strand transfer step. The most potent IN was 2,4-dioxo-4-phenanthren-9-yl-butyric acid ( 27f) with an IC 50 of 0.38 μM against integrase strand transfer. The phenanthrene diketo acids 27d– f were more potent (IC 50 = 2.7–0.38 μM) than the corresponding phenanthridinone diketo acid 16 (IC 50 = 65 μM), suggesting that the polar amide bridge in the phenanthridinone system decreases inhibitory activity relative to the more lipophilic phenanthrene system. This might have to do with the possible binding of the aryl group of the compounds binding to a lipophilic pocket at the integrase active site as suggested by the docking simulations. Molecular modeling also suggested that effectiveness of chelation of the active site Mg 2+ contributes to IN inhibitory potency. Finally, some of the potent compounds inhibited HIV-1 replication in human peripheral blood mononuclear cells (PBMC) with EC 50 down to 8 μM for phenanthrene-3-(2,4-dioxo)butyric acid ( 27d), with a selectivity index of 10 against PBMCs.

11-Methyl-12a-phenyl-9a,12a-dihydrophenanthro[9',10:5,6][1,4]dioxino[2,3-d]thiazole.

In the title compound, C(24)H(17)NO(2)S, the dioxine and thiazoline rings are distorted from planarity towards a half-chair and an envelope conformation, respectively. The configurations of the dioxine ring, the thiazoline ring and the attached phenyl ring are conditioned by the sp(3) state of the two bridgehead C atoms. The phenanthrene system is nearly coplanar with the dioxine ring, while the attached phenyl ring is orthogonal to the thiazoline ring.

4-Nitrophenanthrene

This study at 168 K shows that in the crystal structure of C14H9NO2, the plane of the nitro group is inclined at 72.2 (7)° to the plane of the attached six-membered ring. The phenanthrene system is significantly non-planar.

Simulation of the Semicontinuous Supercritical Antisolvent Recrystallization Process

A model is developed for simulating semicontinuous supercritical antisolvent recrystallization processes. Thermodynamics, hydrodynamics, and mass-transfer issues are addressed. The model makes it possible to calculate the composition and flow-rate profiles of the vapor and liquid phases and the amount of the solid product along the precipitator. The effect of the operating variables is discussed. With reference to a CO2−toluene−naphthalene−phenanthrene system, it is shown that the dissolution of the antisolvent in the liquid phase is usually faster than the evaporation of the solvent, that the two solutes may behave in completely different ways at the same process conditions (for example, phenanthrene can be easily precipitated, while for naphthalene a higher gas-to-liquid flow-rate ratio is needed, to force solvent evaporation), and that under proper operating conditions it is possible to selectively precipitate phenanthrene from a phenanthrene + naphthalene solution.

High-pressure phase equilibria in the systems methane + phenanthrene and methane + 1-phenyldodecane up to 400 MPa

In this paper, experimental data on the high-pressure phase behaviour of the systems methane + phenanthrene and methane + 1-phenyldodecane are presented. For both systems vapour-liquid, solid-fluid, and solid-liquid-vapour equilibrium data were determined. The experiments were carried out for various mixtures covering almost the whole composition range. The temperature range investigated was from 360 to 460 K for the methane + phenanthrene system and from 260 to 400 K for the methane + 1-phenyldodecane system. The maximum pressures exerted on the samples were dependent on the equipment used, either 200 or 400 MPa. The second critical endpoint (s + 1 = g), which is the pressure maximum of the three-phase curve (solid hydrocarbon + liquid + vapour), is, for the methane + phenanthrene system, located at a temperature T = 403.3 ± 0.4 K, a pressure p = 358.9 ± 1.5 MPa, and a mole fraction of phenanthrene in the critical fluid phase x = 0.126 ± 0.009. The coordinates of the second critical endpoint of the methane + 1-phenyldodecane system were found to be T = 277.1 ± 0.4 K, p = 148.0 ± 0.6 MPa, and for the mole fraction of 1-phenyldodecane in the critical fluid phase x = 0.076 ± 0.005.

2-(10-Diethylaminomethyl-2,3,6,7-tetramethoxy-9-phenanthrylmethyl)-1-pyrrolidinecarbonitrile

The title molecule, C 29 H 39 N 3 O 4 , consists of a pyrrolidine and a phenanthrene ring. The mean plane through the pyrrolidine ring atoms is almost perpendicular to that through the phenanthrene ring atoms. The pyrrodiline ring adopts a half-chair conformation, while the fused rings of the phenanthrene system are almost coplanar. In the crystal, molecules are stabilized by van der Waals interactions.

Triphenanthro‐anellierte [18]Annulene mit Alkoxy‐Seitenketten — Eine neue Klasse discotischer Flüssigkristalle

AbstractTriphenanthro‐Anellated [18]Annulenes with Alkoxy Side Chains ‐ A Novel Class of Discotic Liquid CrystalsTwo different types 6 and 16 of [18]annulenes condensed with phenanthrene systems were prepared by cyclocondensation reactions (Schemes 2 and 3). The central 18‐membered rings do not show a macrocyclic diamagnetic ring current. Conformational analyses and X‐ray analyses in the solid state reveal non‐planar structures in which aromatic “islands” are connected by (E)‐configurated olefinic bridges. The introduction of long alkoxy side chains yields a new class of discotic liquid crystals; either ND or hexagonal columnar phases are generated, which were characterized by DSC, microscopy with polarized light, and small‐angle scanning X‐ray.

Structures of 6,9-dimethyl- and 6,9-diisopropyl-[2.2] (1,4)phenanthrenoparacyclophane

Abstract 6,9-dimethyl-6,9-diisopropyl-[2.2] (1,4)phenanthrenoparacyclophane 1, C26 H 24, crystallises in P21/n, with a = 13.963(7) Å, b = 7.745(3) Å, c = 16.867(6) Å, β = 94.03(4)[unk], Z = 4, R(F) = 0.044. 6,9-diisopropyl-[2.2] (1,4)phenanthrenoparacyclophane 2, C30H32, crystallises in P21/n, with a = 10.779(4) Å, b = 11.402(4) Å, c = 18.245(6) Å, β = 90.85(3)[unk], Z = 4, R(F) = 0.046. The steric compression from the substituents at C9 and C10 causes the phenanthrene systems of both compounds to be markedly helical. Absolute torsion angles in the bay region are as large as 32°. The paracyclophane moieties show the usual distortions at the bridgehead carbons, which lie ca. 0.15 Å out of the plane of the other four atoms.

Abc]-Annelated [18]annulenes

Synthesis of [18] annulenes realize for the first time by fusing naphthalene or phenanthrene systems to the 18-membered ring. The decisive synthetic step in each case is performed by a 3-fold cyclic condensation of the corresponding methyl phenylimino arenes. The anilino group is a bulky leaving group, which leads to an extreme stereoselectivity (E:Z> 1000:1)

Nonprostanoid prostacyclin mimetics. 3. Structural variations of the diphenyl heterocycle moiety.

4,5-Diphenyl-2-oxazolenonanoic acid (2) and 2-[3-[2-(4,5-diphenyl-2-oxazolyl)ethyl]phenoxy]acetic acid (3) were previously identified as nonprostanoid prostacyclin (PGI2) mimetics that inhibit ADP-induced aggregation of human platelets in vitro. The effects on biological activity of substitution and structural modification of the 4- and 5-phenyl rings of 3 was examined. Potency showed a marked sensitivity to the introduction of substituents to these aromatic rings and only the bis-4-methyl derivative 9j, IC50 = 0.34 microM, demonstrated enhanced potency compared to the parent structure 3, IC50 = 1.2 microM. Substitution at the ortho or meta positions of the phenyl rings, replacement by thiopheneyl or cyclohexyl moieties, or constraining in a planar phenanthrene system resulted in compounds that were less effective inhibitors of ADP-induced platelet aggregation. In contrast, variation of the heterocycle moiety revealed a much less stringent SAR and many 5- and 6-membered heterocycles were found to effectively substitute for the oxazole ring of 2 and 3. The diphenylmethyl moiety functioned as an effective isostere for 4,5-diphenylated heterocycles since 13aad showed similar platelet inhibitory activity to 3. With the exception of the 3,4,5-triphenylpyrazole derivative 13g, compounds presenting the (m-ethylphenoxy)acetic acid side chain discovered with 3 demonstrated enhanced potency compared to the analogously substituted alkanoic acid derivative. The structure-activity findings led to a refinement of a model of the nonprostanoid PGI2 mimetic pharmacophore.

Light gas solubility in phenanthrene: the hydrogen—phenanthrene and methane—phenanthrene systems

A variable volume equilibrium cell was used to study the hydrogen—phenanthrene and methane—phenanthrene systems. The data were taken along isotherms from 398.2 to 473.2 K and up to pressures of 25.23 MPa. Henry's constants and heats of solution were calculated for both systems. The data indicated that both pressure and liquid mole fraction effects are important in describing deviations from ideal solution as well as heats of solution.

Apparatus and procedure to measure binary total pressure at high temperature fluorene—phenanthrene vapor—liquid equilibria and data reduction by the four-suffix margules model to obtain infinite-dilution activity coefficients

Infinite-dilution fugacity coefficients were obtained for the binary fluorene—phenanthrene system at thirteen temperatures by fitting total pressure across the entire mole fraction range using a computer routine. The four-suffix Margules activity coefficient model, that allows for both positive and negative experimentally observed pressure deviations from the ideal values, was used to correlate data over the full mole fraction range from 0 to 1 by a thermodynamically consistent routine. Samples were well degassed by essentially total sample reflux under sustained vacuum prior to attachment to the vapor pressure apparatus.

ChemInform Abstract: Silicon Modified Reduction and Reductive Alkylation. Application to the Phenanthrene System.

AbstractThe bromophenanthrenes (I) react with butyllithium and trimethylsilyl chloride (II) to give the trimethylsilylphenanthrenes (III) which are reduced with lithium in liquid ammonia to form the 9,10‐dihydrophenanthrenes (IV).

The insertion and extrusion of heterosulfur bridges. XV. S‐bridging of 2,2′‐binaphthyl and 1‐(2‐naphthyl)cyclohexene. Studies on hydrodehalogenation during the reaction

AbstractRegioselectivity occurs in the sulfur‐bridging reactions of 2,2′‐binaphthyl (1) and 1‐(2‐naphthyl)cyclohexene (7) by means of hydrogen sulfide and a chromia‐alumina‐magnesia catalyst (designated I) in a flow apparatus at 550°. Thus, 1 gives a higher yield (6.1%) of dinaphtho[1,2–6:2′,l'‐d]thiophene from 1,1′‐bridging than of dinaphtho[1,2‐b:2′,3′‐d]thiophene (3.4%) from l,3′‐bridging. No product expected from 3,3′‐bridging was identified. Substrate 7 undergoes both dehydrogenation and bridging to yield 2‐phenylnaphthalene (8%), benzo[b]naphtho[2,1‐d]thiophene (9%) from alpha bridging, and benzo[b]naphtho[2,3‐d]thiophene (3%) from beta bridging into the naphthalene ring.Exploratory studies showed that either sulfided catalyst I or a sulfided molybdenum(VI) oxide‐alumina‐cobalt(II) oxide catalyst (II) effects hydrodehalogenation of various monohalo‐ and polyhaloarenes (where halo, X, is chloro or bromo) at 450–550°. In the biphenyl, phenanthrene, naphthalene, and pyrene systems, halogen was lost either under sulfur‐bridging conditions or under hydrogenolysis conditions, i.e. with methanol as a reactant. For every substrate the parent arene was isolated or identified as a reaction product. In selected experiments, acid HX was also identified in the effluent. Use of hydrogen sulfide as a reactant led to formation of dibenzothiophene and phenanthro[4,5‐bcd]thiophene as main products in the biphenyl and phenanthrene systems, respectively; while use of methanol as a reactant gave small amounts of methyl bromide (for X = Br) and methylarenes.