Phenanthrene Derivatives Research Articles

Epoxidation of polyaromatics using HOF·CH 3CN

The reaction of the HOF·CH 3CN complex, made directly by passing fluorine through aqueous acetonitrile, with some phenanthrene and pyrene derivatives results in fast epoxidation.

Geochemical significance of the aromatic hydrocarbon distribution in the bitumens of the Puertollano oil shales, Spain

The bituminous series of the Puertollano basin consists of three oil shale beds named PA, PB and PC from top to bottom. In this work, results from the study of the aromatic fractions of the bitumens are presented. The gas chromatographic traces are dominated by phenanthrene derivatives associated with variable contributions of arborane/fernane derivatives and benzohopanes and, overall, small amounts of chrysene derivatives and secohopanes. The compounds can be considered as part of two sub-groups: the first one consists of those compounds derived from regular hopanes such as secohopanes, benzohopanes, fully aromatized hopanes, and degradation products of hopanes such as alkylated chrysenes and naphthalenes. The second group is composed of arborane/fernane derivatives and their degradation products such as alkylated phenanthrenes and tetrahydrophenanthrenes. Both groups of compounds appear to be indicative of a strong bacterial input to the sedimentary organic matter.

Application of 2D NMR Spectroscopy in Structural Elucidation of some Phenanthrene Derivatives from Indian Orchidaceae Plants

Application of 2D NMR Spectroscopy in Structural Elucidation of some Phenanthrene Derivatives from Indian Orchidaceae Plants

A versatile approach to the synthesis of 4,5-dioxoaporphine and 3,4-dioxocularine alkaloids. One-Pot sequential [formula omitted] ring formation from arylacetamides

Cyclization of biarylacetamides to their phenanthrene derivatives is promoted by oxalyl chloride/stannyl chloride. The reaction proceeds with a second cyclization in which the oxalyl fragment acts as an α-dicarbonyl transfer agent to give 4,5-dioxoaporphine alkaloids in a single step. This double cyclization was also applied to aryloxyphenyl acetamides to give the corresponding 3,4-dioxocularine alkaloids. Decarbonylated aristocularine alkaloids were also formed in this case.

Excimer fluorescence from phenanthrene-9-carboxylate derivatives

Phenanthrene and most of its known derivatives do not form stable, fluorescent excimers. Moderately intense, long-lived excimer fluorescence has been observed for lactone and lactam derivatives of phenanthrene. The solvatochromic shift of this excimer fluorescence is similar to that previously reported for the pyrene excimer. Stabilization of the excimer is attributed to the increased polarizability of phenanthrene by a coplanar carbonyl substituent. Excimer formation is not observed for a coplanar cyano substituent or an orthogonal carbonyl substituent.

The photochemistry of 3,3′,4,4′-tetramethoxy-and 4-hydroxy-3,3′,4′-trimethoxystilbene — models for stilbene chromophores in peroxide-bleached, high-yield wood pulps

The photochemistry of the title compounds has been investigated in ethanol and tetrahydrofuran solution under aerobic and anaerobic conditions. Direct irradiation of trans-3,3′,4,4′-tetramethoxystilbene (trans-1) in deoxygenated ethanol leads to the rapid establishment of a photostationary state with the cis isomer, and the slower formation of the ethyl ether corresponding to addition of ethanol across the olefinic C=C bond and cyclobutane dimers. The same products are formed upon photolysis in the presence of oxygen under the same conditions but, in addition, two isomeric tetramethoxyphenanthrenes and 3, 4-dimethoxybenzaldehyde are formed. Photolysis of trans-1 in oxygenated tetrahydrofuran leads to the same products in different relative yields. Quantum yields for cis, trans photoisomerization, phenanthrene formation, and addition of ethanol have been determined by ferrioxalate actinometry. Direct irradiation of tran-4-hydroxy-3,3′,4′-trimethoxystilbene (trans-2) in ethanol solution also results in rapid cis–trans isomerization and the formation of (three) isomeric phenanthrene derivatives in photolyses carried out in the presence of oxygen, although the material balance is low. The various products of photolysis of trans-2 have been independently synthesized by desilylation of the products isolated from photolysis of trans-4-tert-butyldimethylsiloxy-3,3′,4′-trimethoxystilbene (trans-3) under similar conditions. Fluorescence-quenching experiments have been carried out to determine the relative rates of quenching of the excited singlet states of trans-1 and trans-2 by alcohols and oxygen. The formation of aldehydes is proposed to arise via reaction of superoxide ion with stilbene radical cations, which are formed by electron-transfer quenching of the stilbene excited singlet state by oxygen. Key words: stilbenes, lignin, photochemistry, photooxidation.

X-Ray and quantum chemical studies of strained phenanthrenes

The synthesis of the highly strained helical 4-tert-butyl-1,5,8-trimethylphenanthrene 6 was achieved by photochemically induced dehydrocyclization. The helical deformation of the aromatic carbon skeleton in the reported X-ray structure is found to be 36.6° which is the largest value found for a phenanthrene hydrocarbon. A systematic quantum chemical investigation of strained 4,5-substituted phenanthrene derivatives (R, R′ : F, Cl, methyl, tert-butyl) at ab initio Hartree–Fock and semiempirical AM1 theoretical levels is presented. The geometrical parameters describing the strain in these helical molecules are compared with X-ray data from the literature and are found to be generally in good agreement. Substantial deviations between theory and experiment for the helical deformation angles are observed in the case of the chlorine-substituted molecules (ca. 5°) which indicates the importance of crystal packing effects. A prediction of the structure of the unknown 4,5-di-tert-butylphenanthrene 5, that could be detected by GC–MS, but has not been isolable so far is also given. The total strain energies of 5 and 6 are calculated to be 49.6 and 34.0 kcal mol–1, respectively, and are distributed to non-bonded and aromatic ring deformation contributions.

Fluorescence Quenching Kinetics of Phenanthrene Covalently Bound to Sodium Poly(acrylate-co-acrylamide): Effects of Ionic Strength and Counterion

Steady-state and time-resolved fluorescence quenching experiments were performed on a series of random terpolymers comprising sodium acrylate, acrylamide, and a phenanthrene (Phen) derivative. The polymers in this series had a fixed Phen loading (4 mol %) and differed in the relative composition of the acrylate and acrylamide monomers. Fluorescence quenching by Tl+ and Cs+ was measured as a function of ionic strength in basic aqueous solutions. The apparent bimolecular rate constant for quenching (kq) is on the order of 1012 M-1 s-1 at low ionic strength and diminishes by approximately 1 order of magnitude at 14 mM added ionic strength. This behavior is independent of the particular group 1A counterion salt but does depend on the polyelectrolyte linear charge density. At relatively high quencher concentration both Tl+ and Cs+ display negative curvature in their I0/I Stern−Volmer plots. “Displacement” experiments were carried out in which K+ is added to a solution of the polyelectrolyte with a fixed concen...

Drug metabolizing enzyme induction by benzoquinolines, acridine, and quinacrine; tricyclic aromatic molecules containing a single heterocyclic nitrogen.

Rats were treated with nitrogen-containing phenanthrene (3,4-, 5,6-, or 7,8-benzoquinoline) or anthracene (acridine or quinacrine) derivatives at a dose of 75 mg/kg, daily for 3 days. The hepatic drug metabolizing enzyme response ranged from no induction (quinacrine) through low (5,6-benzoquinoline), intermediate (acridine), and high (3,4-benzoquinoline) magnitude increases of only phase II enzymes, to induction of both phase I and phase II enzymes (7,8-benzoquinoline). The phase I enzyme response of 7,8-benzoquinoline was an induction of CYP1A. All three benzoquinolines, but neither anthracene derivative, elevated NAD(P)H quinone oxidoreductase activity. A similar pattern but of lesser magnitude was seen with glutathione S-transferase activity. 3,4-Benzoquinoline was the only agent to significantly increase microsomal epoxide hydrolase activity (2,3-fold). Both 3,4- and 7,8-benzoquinoline increased UDP-glucuronosyltransferase activity toward 4-nitrophenol (40% and 70%, respectively), but only the 3,4-isomer increased activity toward morphine (75%), diclofenac (75%), and testosterone (23%), and only the 7,8-isomer increased activity toward chloramphenicol (105%). 3,4-Benzoquinoline elevated the hepatic mRNA concentration of UGT2B1 but not UGT1*6. Acridine treatment increased UDP-glucuronosyltransferase activity toward morphine (47%), 1-naphthol (28%), testosterone (19%), and estrone (19%). Quinacrine failed to elevate any UDP-glucuronosyltransferase activity and depressed activities toward testosterone and estrone by 20%. This study shows that some tricyclic aromatic compounds containing a single heterocyclic nitrogen atom have the potential for use as chemoprotective agents based upon their ability to selectively induce only phase II enzymes.

Electroactive protecting groups and reaction units. Part 4. Mesolytic O–CO bond cleavage versus intramolecular cyclization reaction in enol trifluoroacetate cation radicals. A kinetic and mechanistic investigation

The one-electron oxidation of two β,β-dimesityl enol trifluoroacetates with different substituents R at Cα was investigated. For the first time enol trifluoroacetate cation radicals could be reversibly monitored in cyclic voltammetry experiments allowing the determination of the rate constants of their follow-up reactions. While mesolytic cleavage of the O–CO bond (kf= 1.4 s–1) with direct formation of an α-carbonyl cation constitutes the primary reaction of the enol trifluoroacetate cation radical with R = But, the one with R = Ph exclusively cyclizes (kf= 75 s–1) to a phenanthrene derivative. This change in reactivity can be rationalized by the different nature of the electrophoric system as a function of the substituent R.

Synthesis, Structure, and Electronic Properties ofsyn-[2.2]Phenanthrenophanes: First Observation of Their Excimer Fluorescence at High Temperature

Two syn-[2.2](1,6)- and -(3,6)phenanthrenophanes, 1a,b, were synthesized for the first time by means of intermolecular [2 + 2] photocycloaddition of the corresponding divinylphenanthrenes. Phenanthrenophanes 1a,b were obtained as mixtures of two (exo,exo and exo,endo) and three (exo,exo, exo,endo, and endo,endo) structural isomers, respectively, which were isolated by reversed-phase HPLC and gel permeation chromatography. All of the isomers, whose structures were characterized mainly on the basis of 1H NMR spectroscopy, were in a syn conformation. X-ray crystallographic analysis of exo,endo-1a was successful, also in agreement with the results of 1H NMR. Birch reduction of 1b, followed by DDQ oxidation, afforded [4.4](3,6)phenanthrenophane 5b in an anti conformation, due to opening of the cyclobutane rings. The absorption spectra of 1b were relatively similar to that of phenanthrene itself, while those of 1a were rather broadened and red-shifted compared to those of phenanthrene and 1b. In both cases, the spectra were independent of the configuration of the cyclobutane rings. The fluorescence spectra of 1b exhibited sharp vibrational structures, as in phenanthrene, suggesting fluorescence from the locally excited state. On the other hand, 1a afforded a broad and structureless emission due to the excimer fluorescence, even at room temperature. This is the first observation of the excimer emission almost free from the monomer-like emission for phenanthrene derivatives at rather high temperature. Such differences in the absorption and fluorescence spectra between 1a,b can be explained reasonably in terms of differences in the arrangement of the two phenanthrene rings; they are tightly held almost in parallel for 1a, according to the X-ray structural analysis, while tilted by the dihedral angle of ca. 30° for 1b on the basis of MM2 calculations.

Chalcone and dihydrochalcone derivatives from the orchid Lusia volucris

A new dihydrochalcone derivative, lusianin, two other known chalcones and a phenanthrene derivative were isolated from the orchid Lusia volucris. The two chalcones and the phenanthrene derivative were characterized as 2-propene-1-one-1-(2′,4′-dihydroxy-3′-methoxyphenyl)-3-(4″-methoxyphenyl) and 2-propene-1-one-1-(2′-hydroxy-4′-methoxyphenyl)-3-(4″-methoxyphenyl) and 6-hydroxy-2,4,7-trimethoxyphenanthrene(batatasin-I), respectively, by independent spectral analysis of the compounds and their acetyl derivatives. The structure of lusianin was established as 1-propanone-1-(2′,4′-dihydroxy-3′-methoxyphenyl)-3-(4″-methoxyphenyl) from spectral and chemical evidence.

Cycloaromatization of 6,7-benzobicyclo[8.3.0]trideca-6,10-diene-3,8-diyne-1,5-diols via diradical intermediates

Exposure of 1a to MsCl in the presence of Et 3 N, followed by treatment with H 2 O provided anthracene and phenanthrene derivatives 4 and 5 in an (1:1) product ratio via 1,6-didehydro[10]annulene intermediate. Under the same conditions 2a gave naphthalene derivative 6 in 9% yield via ene-yne-allene intermediate. These transformation could be explained by the rapid diradicalforming cycloaromatization. 1a reacted with MsCl in the presence of Et 3 N, followed by treatment with H 2 O to give 4 and 5 in an (1:1) product ratio. Under the same conditions, 2a gave 6 in 9% yield. Both reactions proceed via diradical intermediates.

The spectroscopy and photophysics of three 9,10-diaryl phenanthrene derivatives

The spectroscopic and photophysical properties of three 9,10-diaryl phenanthrene derivatives (fluorophenyl, methoxyphenyl and hydroxyphenyl phenanthrenes) have been studied in cyclohexane and in methanol. The UV absorption, fluorescence excitation and emission spectra have been recorded for these three compounds. From these experiments, molar extinction coefficients, Stokes shifts and quantum yields have been calculated or measured. Fluorescence lifetimes have also been measured by using a time-correlated single-photon counting technique. The radiative decay rate constants based on the quantum yields and lifetimes have finally been obtained. Solvent polarity and the nature of the substituent have an influence on the spectroscopic characteristics.

Monocyclic Aromatic Hydrocarbons in Bile of Flounder Exposed to a Petroleum Oil

Abstract The bioaccumulation of contaminants in tissues of fish exposed to petroleum hydrocarbons is of concern because of the toxicity associated with polycyclic aromatic compounds (PAC). Exposure of Winter flounder (Pseudopleuronectes americanus) to several concentrations of Hibernia crude oil in sediments, for four months during the winter, resulted in a dose-response in the accumulation of hydrocarbons in muscle tissue and the elimination of metabolites (glucuronides and sulphates) through the gall bladder bile. Results of a multispectroscopic analysis using ultraviolet/fluorescence (uv/f) and gas chromatography-mass spectromemry (GC-MS) are presented. In muscle tissue, the monocyclic aromatic hydrocarbons were previously shown to predominate over alkylated PAC, while parental PAC were least detectable. Naphthalene and phenanthrene derivatives were more easily characterised as bile metabolites (GC-MS) than benzenoid derivames which, according to uv/f analysis also represent a large fraction of the met...

Ferroelectric switching in columnar phases of novel chiral discotic liquid crystals

Novel 2,3,6,7,9,10-hexasubstituted phenanthrene derivatives have been synthesized, which showed broad enantiotropic columnar phases. A mixture of one representative bearing six (S)-2-methyl-3-oxa-decanoyloxy side chains with its 1,2,3,6,7,8-hexasubstituted structural isomer showed a tilted columnar phase and exhibited ferroelectrical switching with a maximum spontaneous polarization of 54 nC cm–2. Here the detailed investigations of the electrical and optical properties of this mixture are presented. The possible phase structure is also discussed.

New switchable columnar liquid crystals

Abstract Penta- and hexa-substituted phenanthrenes and penta-substituted benzo[c]-phenanthrenes have been synthesized; these exhibit columnar phases and are electrically switchable when bearing chiral side chains. The liquid crystalline and electro-optical properties are described. A strong tri-state switching behaviour is observed with the phenanthrene derivatives. A helical phase structure, responsible for this switching behaviour, is proposed and the possible mechanism of the columnar phase switching process is discussed.

Proton sponges

Since the review by Staab and Saupe (Angew. Chem., Int. Ed. Engl., 27 (1988) 865), the field of “proton sponges” has seen great progress, partly a result of the efforts of Staab himself. The present work updates the literature references up to the end of 1993 and has a different scope since it is mainly based on crystallographic results. A collection of nearly 70 X-ray structures has been examined and their geometrical parameters discussed. An effort has been made to relate the geometrical characteristics of the solid-state structures to solution properties such as pKa and rate constants for intermolecular proton transfer. The relationships between the chemical structure and the basicity of proton sponges are examined for naphthalene, fluorene, phenanthrene, biphenyl and benzene derivatives. The theoretical as well as experimental data for the intramolecular hydrogen bonded [NH⋯N]+ system are discussed with special emphasis on crystallographic data. The paradigmatic case of 1,8-bis(dimethylamino)naphthalene and its cation, has been studied by means of semiempirical AM1 calculations. Finally, the most relevant structural conclusions are summarized.

ChemInform Abstract: A New Route to Phenanthrene Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Reaction of CH Acids with 2‐Arylidenecycloalkanones: Synthesis of . beta.‐Keto Acid Anilide Derivatives of Naphthalene, Indene, Fluorene, and Phenanthrene.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.