2-anthracenecarboxylic Acid Research Articles

Solvent Switching of Stereoselectivity in [4 + 4] Photocyclodimerization of 2-Anthracenecarboxylic Acid

Abstract Stereochemistry of the major photocyclodimer is switched from 52% anti-head-to-head to 51% anti-head-to-tail among the four stereoisomers produced upon irradiation of 2-anthracenecarboxylic acid at low temperatures by changing the solvent from dichloromethane to methanol, through a critical control of the hydrogen bonding and dipole–dipole interactions.

Pressure and Temperature-Controlled Enantiodifferentiating [4+4] Photocyclodimerization of 2-Anthracenecarboxylate Mediated by Secondary Face- and Skeleton-Modified γ-Cyclodextrins

A series of secondary-face-substituted and skeleton-modified gamma-cyclodextrins (gamma-CDs) were prepared as chiral hosts for enantiodifferentiating [4+4] photocyclodimerization reactions of 2-anthracenecarboxylic acid (AC). These gamma-CD derivatives form stable ternary complexes with ACs, with altroside-bearing gamma-CDs undergoing induced-fit conformational changes upon complexation, and the photocyclodimerization of AC was, thus, dramatically accelerated. The enantiomeric excess (ee) of anti-head-to-head cyclodimer 3 was greatly enhanced in general with altroside-bearing gamma-CDs 7-9. Although mono-altro-gamma-CD 9 and 3A-azido-3A-deoxy-altro-gamma-CD 7 gave 2 in ee's smaller than those obtained with native gamma-CD, 3A-amino-3A-deoxy-altro-gamma-CD 8 yielded 2 in much higher ee's, which is likely to be ascribed to the combined effects of the less-symmetric cavity and the electrostatic interactions. The influence of temperature and high pressure on the supramolecular photochirogenic reaction has been investigated in depth. An ee as high as 71% was obtained for cyclodimer 2 in the photocyclodimerization of AC mediated by 8 at 210 MPa and -21.5 degrees C.

Enantiodifferentiating [4 + 4] photocyclodimerization of 2-anthracenecarboxylate catalyzed by 6 A,6 X-diamino-6 A,6 X-dideoxy-γ-cyclodextrins: Manipulation of product chirality by electrostatic interaction, temperature and solvent in supramolecular photochirogenesis

6 A,6 X-Dideoxy-6 A,6 X-diamino-γ-cyclodextrins (X = B, C, D and E) 5a– d were synthesized as chiral hosts for catalyzing the enantiodifferentiating [4 + 4] photocyclodimerization of 2-anthracenecarboxylic acid (ACA). The electrostatic interaction between 5a– d and ACA efficiently affected the preorganization of two ACA molecules within the γ-CD cavity, and improved the yields of head-to-head cyclodimers. By lowering the reaction temperature or solvent polarity, the electrostatic interaction was further enhanced. The anti-to-syn ratio of the head-to-head isomers gradually increased by changing the host from 5a to 5d (with increasing distance between the two amino groups on the CD rim), demonstrating a good structure–function relationship in this supramolecular photoreaction system. The chiral sense and enantiomeric excess of the photoproducts obtained are significantly affected, and even inverted, by solvent composition and reaction temperature. This temperature- and solvent-controlled chirality switching behavior is proven to originate from the contribution of non-zero differential entropy (ΔΔ S ‡) in the enantiodifferentiating process. This finding is the first example of a chirality inversion driven by entropy-related factors, such as solvent and temperature, in a non-sensitized asymmetric photoreaction. The sign of ΔΔ S ‡ was switched by the composition of solvent and exhibited an excellent compensatory relationship against the differential enthalpy (ΔΔ H ‡), revealing that the photoenantiodifferentiation is governed not only by enthalpy but also by entropy, and also that the enantiodifferentiation mechanism does not vary throughout the whole system, irrespective of the condition changes.

Stereoselective Photodimerization of 2-Anthracenecarboxylic Acid Using a Cation-Charged PSMP12-Cyclodextrin Template

Two pyridinium groups were introduced into β-cyclodextrin (β-CD) at the A and E glucose units to make a molecular flask for controlling the stereo-selectivity of photodimerization of 2-anthracenecarboxylic acid. When the photodimerization of 2-anthracenecarboxylic acid was carried out in the presence of bispyridinio-appended β-CD, the relative yield of one of the configurational isomers was increased 1.5-fold compared to the corresponding yield in aqueous solution. The optical yields of the photodimerization reaction products also increased more than 10-fold by the addition of bispyridinio-appended β-CD.

Regioselective imprinting of anthracenecarboxylic acids onto TiO 2 gel ultrathin films: an approach to thin film sensor

Ultrathin films of titanium oxide gel were imprinted with aromatic carboxylic acids, e.g. 4-(4-propyloxyphenylazo)-benzoic acid (C 3AzoCO 2H) and anthracenecarboxylic acids (2-AnCO 2H and 9-AnCO 2H), by repeatedly immersing a gold-coated quartz crystal microbalance (QCM) electrode or a quartz plate in a mixed solution of given carboxylic acids and titanium- n-butoxide (Ti(O- n Bu ) 4) in toluene/ethanol. Regular film growth was confirmed by frequency shifts of QCM measurement and by appearance of the absorption for aromatic moieties in UV-visible spectroscopy. The template molecules were completely removed upon treatment with 1% ammonia solution. The resulting films showed sensitive mass increases for guest binding of various carboxylic acids, and the isomeric structure of the two anthracenecarboxylic acids (2- and 9-isomers) was discriminated by the imprinted films. Together with our previous results, major molecular selectivities—functional selectivity, structural selectivity, regioselectivity, and enantioselectivity—are all achieved by imprinted TiO 2 gel films.

Diffusion-limited extraction of organic ions by a track-membrane interfaced vacuum inlet.

Glycerol-wetted track membranes (polyethylene terephthalate) were used to interface a low-vacuum facility (approximately (10(-3) Torr) to an ambient pressure liquid analyte. High-field charge extraction conditions were routinely maintained between the liquid samples and a grid collector. The latter was positioned just near to the vacuum-facing side of such membranes. Upon establishing a steady-state charge extraction regime, the collector currents were monitored and recorded at various solute concentration levels. The collector currents, which depend on solute concentration, were found to agree with recent theoretical treatments of such processes. Both positively- and negatively-charged species from organic solutions were routinely extracted. Ion injection for the low- and the high-mobility species has favored the diffusion-limited and the evaporation-limited schemes, respectively. Variable concentrations of 1-pyrenoyl-methylpyridinium bromide as well as naphthylacetic and anthracenecarboxylic acids in glycerol were used.

Supramolecular catalysis of the enantiodifferentiating [4 + 4] photocyclodimerization of 2-anthracenecarboxylate by gamma-cyclodextrin.

2-Anthracenecarboxylic acid (AC) makes a very stable 1:2 inclusion complex with gamma-cyclodextrin (gamma-CDx) (K(1) = 161 +/- 25 M(-1), K(2) = 38 500 +/- 3300 M(-1) at 25 degrees C). The formation of the 1:2 inclusion complex accelerated the photocyclodimerization of AC. The 1:2 inclusion could be clearly verified by UV-vis, CD, and (1)H NMR spectroscopies. Although these spectroscopies provide little information about the structural isomers of the inclusion complex, there should be several structural isomers of the 1:2 inclusion complex which have a different longitudinal orientation of the guest molecules in the cavity. The isomer distribution of the photodimerization product primarily depends on the population of these orientational isomers of the 1:2 inclusion complex in the ground state before photoreaction, because, in the lifetime of the excited singlet state, exchanging the orientation is impossible. The enantioselectivity of the photodimerization originates from the difference in the stability of the diastereomeric pair of orientational isomers of the 1:2 inclusion complex in the ground state, which are the precursors of the enantiomers of a specific chiral cyclodimer. The ee of a chiral cyclodimer 2 was 32% at 25 degrees C and was enhanced by lowering the temperature to 41% at 0 degrees C. This is the highest value reported for the asymmetric photodimerization in solution.

The influence of hydrogen bonding on the photoinduced interaction of 9-anthracenecarboxylic acid and xanthene dye esters

The interaction of 9-anthracenecarboxylic acid with xanthene esters in chloroform solution was studied using emission spectra, fluorescence lifetime, IR spectra and 1H NMR spectra. The results show that there exists both dynamic and static fluorescence quenchings. Dynamic quenching is a diffusion controlled process while static quenching is affected by hindrance of substituents adjacent to the hydroxyl groups in the xanthene moiety. Thus an intermolecular hydrogen bond interaction model between the hydroxyl groups of xanthene dye esters and 9-anthracenecarboxylic acid is proposed, and this is supported by IR and 1H NMR spectra data. The binding constant for fluorescein and 9-anthracene carboxylic acid is 982 M −1, while it is only 81 M −1 for the eosin ester and 9-anthracenecarboxylic acid. No apparent static interaction was observed in methanol solution. This may be explained in terms of hydrogen bonding between the hydroxyl group of methanol to anthracenecarboxylic acid, being in competition with that from the hydroxy group of the xanthene dye esters to 9-anthracene carboxylic acid.

Dynamics of Semiconductor-to-Dye Electron Transfer for Anthracene Dyes Bound to Different Sized TiO2 Particles

The photosensitization of different sized TiO2 nanoparticles by anthracenecarboxylic acid dye molecules has been studied using transient absorption spectroscopy. These experiments primarily yield information about the semiconductor-to-dye electron transfer reaction. Our measurements show that for TiO2 particles in the 4 to 40 nm size range, the rate of this reaction does not depend on the particles' size. The results were analyzed using a model where the electrons are assumed to be evenly distributed over the surface of the particle. To reproduce our experimental results with this analysis, the scaling parameter that describes the distance dependence of the semiconductor-to-dye electron transfer reaction must be > 180 nm. We do not consider this to be physically reasonable. An alternative explanation is that the injected electrons are in localized trap sites that are spatially close to the dye radical cation, i.e., they are not randomly distributed over the particle surface. The observation of single expo...

Effect of Structure on Electron Transfer Reactions between Anthracene Dyes and TiO2 Nanoparticles

Photoinduced electron transfer to TiO2 nanoparticles has been examined for the 1-, 2-, and 9-isomers of anthracenecarboxylic acid. TiO2 samples with either anatase or amorphous crystal structures w...

Oxidation of aliphatic side chains in anthracene diels-alder adducts

An efficient oxidation of methyl and primary side chains of anthracene Diels Alder adducts with KMnO4 is reported. The oxidation leaves the bridgehead methines intact providing Diels-Alder adducts of anthracenecarboxylic acids. Retro Diels-Alder reaction allows for the preparation of the parent anthracenecarboxylic acids.

Binding of carprofen to human and bovine serum albumins.

The binding of carprofen (CP) to human serum albumin (HSA) and bovine serum albumin (BSA) was compared using equilibrium dialysis method. The affinity of CP for the primary binding site was BSA > HSA. However, the number of primary binding sites (n1) was 1.94 on HSA, considerably greater than that on BSA (0.79). The displacement of the binding of CP to HSA and BSA was studied in the presence of phenylbutazone (PB, site I marker), ibuprofen (IB, site II marker) or 2,3,5-triiodobenzoic acid (TIB, both site I and II marker). The binding of CP to HSA was altered by PB, IB and TIB, while the binding of CP to BSA was not changed by PB, although it was reduced by IB and TIB. These results suggested that, for the binding of CP, HSA has two major sites (site I and site II), whereas BSA has a single primary site (site II). The binding characteristics of 2-anthracenecarboxylic acid with HSA and BSA were found quite similar to those of CP. Thus, it seemed that long, planar compounds with a carboxyl group at one end can bind to site I and site II on HSA, but only to site II on BSA. The difference between HSA and BSA in the affinity of site I may be due to the difference in the basic and hydrophobic amino acid residues.

Sensitive Fluorescence Labeling Reagents for High Performance Liquid Chromatography of Carbonyl Compounds1

Highly sensitive and moderately reactive derivatization reagents having an anthracene moiety as a fluorophore and carboxylic acid hydrazide of O-aralkylhydroxylamine as a reacting group toward the carbonyl function have been developed. The derivatization reagents, anthracene-1- and 2-carboxylic acid hydrazides and O-(1-, 2- and 9-anthrylmethyl)-hydroxylamines, were readily prepared from the corresponding anthracenecarboxylic acids in several steps. The carbonyl compounds underwent facile derivatization with these reagents under mild conditions. The resulting hydrazones and oximes were highly responsive to a fluorescence detector in high performance liquid chromatography, the limits of detection being 50 and 20 fmol, respectively.

Photooxidation of anthracene derivatives in AOT/heptane reversed micelles

The reactivity of different anthracene derivatives toward singlet oxygen has been studied in AOT reverse micelles in heptane as a function of the AOT concentration and w(w = water AOT ) ratio. The reactivity of 9,10-dimethylanthracene, a compound that can be assumed to remain in the heptane, is independent of both AOT and water concentration. For solutes totally incorporated to the micelles (anthracene carboxylic acid (AC −) and dimethyl ethyl-3-(9-anthryl)-propylammonium bromide (AN +), the aromatic consumption rate is independent of AOT concentration but increases when w increases. The w dependence is larger for AC − than for AN +, a result that can be explained in terms of a displacement of AC − toward the micellar water pools. For this compound, the computed bimolecular rate constant becomes, at large w, very close to that obtained in bulk water. The reactivity of anthracene methanol (AM) changes both with the AOT concentration and w. The partition of AM between the micelles and the n-heptane pseudophase was obtained from quenching experiments employing Ru(bpy) 3 +2 as fluorescent probe. The 1O 2-AM results can be explained in terms of the partition of AM and an intramicellar bimolecular rate constant of 1.1 × 10 7 M −1 s −1. This value is larger than that obtained when ethanol is employed as solvent.

Intramolecular exciplex formation and fluorescence quenching as a function of chain length in .omega.-dimethylaminoalkyl esters of 2-anthracenecarboxylic acid

Intramolecular exciplex formation and fluorescence quenching as a function of chain length in .omega.-dimethylaminoalkyl esters of 2-anthracenecarboxylic acid

New sensitive derivatization of hydroxysteroids for high-performance liquid chromatography with fluorescence detection

New highly sensitive and moderately reactive derivatization reagents for hydroxysteroids have been developed. Two derivatization reagents, 1-anthroyl nitrile and 9-anthroyl nitrile, were readily prepared from the corresponding anthracenecarboxylic acid in two steps. The hydroxysteroid was condensed with the anthroyl nitrile in the presence of triethylamine under mild conditions. The resulting ester showed a single peak of the theoretical shap on the chromatogram and provided excellent sensitivity. The detection limit of the C-21 ester formed from cortisol was 10 pg in normal-phase chromatorgraphy.

Model for photosynthetic light harvesting system: Energy transfer in anthracene- and biphenyl-cholorophyll derivatives

An intramolecular energy transfer from the ultraviolet absorbing donor to the pyro-pheophorbide a moiety occurs with high efficiency in model antenna compounds composed of 4-phenylbenzoic acid or anthracenecarboxylic acid and pyropheophorbide a. The energy transfer mechanism involves a Förster tyoe dipole-dipole coupling between the donor transition dipole(s) and the acceptor transition dipole(s) represented by the Soret band of the pyropheophorbide a moiety.

ChemInform Abstract: AROMATIC COMPOUNDS WITH THREE FUSED CARBOCYCLIC RING SYSTEMS: ANTHRACENE, PHENANTHRENE, AND RELATED COMPOUNDS

Publisher Summary Derivatives of the two hydrocarbons, anthracene and phenanthrene, C14H10, both containing three condensed benzene rings, are widely distributed in nature, for example, anthraquinone which is found, together with other polycyclic hydrocarbons, in automobile exhaust and thus, it is a minor constituent in the atmospheres of large cities. Anthracene was of commercial value as the primary intermediate for the manufacture of anthraquinone and the extensive range of polycyclic quinone dyestuffs, but anthraquinone is now largely prepared directly from phthalic anhydride and benzene. Industrial applications for phenanthrene are very few. This chapter discusses the methods of formation, synthesis, properties and reactions of anthracenes and its homologs such as alkyl-, aryl-anthracenes, aminoanthracenes, hydroxyanthracenes (anthrols), anthracenecarboxylic acids and their functional derivatives. Of the theoretically possible anthraquinones (anthracenequinones) only the 1,2-, 1,4- and 9,10-isomers are known but hydroxylated derivatives of others exist. A series of hydrocarbons known as bianthryls and their derivatives, are derived from the linkage of two anthryl units. The homologs of phenanthrene include the alkyl-phenanthrenes, aminophenanthrenes or phenanthrylamines, hydroxyphenanthrenes or phenanthrols, formyl- and acyl-phenanthrenes, phenanthrenecarboxylic acids, phenanthrene quinones and biphenanthryls.

Absorption and Fluorescence Spectra of Anthracenecarboxylic Acids. II. 1- and 2-Anthroic Acids

Abstract The absorption and fluorescence spectra of 1- and 2-anthroic acids (1- and 2-anthracenecarboxylic acids) in alcoholic solvents have been observed as a function of solute concentration. It was revealed that 1- and 2-anthroic acids form hydrogen-bonded dimers in their ground states. The equilibrium constants for dimer formation are : 1.2×104 mol−11 for 1-anthroic acid in methanol and 2.0×104 mol−11 for 2-anthroic acid in ethanol. Owing to dimer formation, the lowest frequency absorption band of 1-anthroic acid was uniformly displaced to the red, while that of 2-anthroic acid was distinctly resolved into two bands. The band assignment was confirmed by the method of photoselection. No excimer-type fluorescence was observed in 1- and 2-anthroic acids. The lack of mirror-symmetry relationship between the absorption and fluorescence spectra of 1-anthroic acid is explained by the geometrical relaxation in its excited state.

ChemInform Abstract: ABSORPTION AND FLUORESCENCE SPECTRA OF ANTHRACENECARBOXYLIC ACIDS. I. 9‐ANTHROIC ACID AND FORMATION OF EXCIMER

Chemischer InformationsdienstVolume 9, Issue 50 Physical Organic Chemistry ChemInform Abstract: ABSORPTION AND FLUORESCENCE SPECTRA OF ANTHRACENECARBOXYLIC ACIDS. I. 9-ANTHROIC ACID AND FORMATION OF EXCIMER S. SUZUKI, Search for more papers by this authorT. FUJII, Search for more papers by this authorN. YOSHIIKE, Search for more papers by this authorS. KOMATSU, Search for more papers by this authorT. IIDA, Search for more papers by this author S. SUZUKI, Search for more papers by this authorT. FUJII, Search for more papers by this authorN. YOSHIIKE, Search for more papers by this authorS. KOMATSU, Search for more papers by this authorT. IIDA, Search for more papers by this author First published: December 12, 1978 https://doi.org/10.1002/chin.197850052AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume9, Issue50December 12, 1978 RelatedInformation