Isomers Of Dihydroxynaphthalene Research Articles

Identification of four isomers of Dihydroxynaphthalene by using a Briggs-Rauscher oscillating system

A novel method for identification of four isomers of dihydroxynaphthalene (DHN) was reported by their different perturbation effects on a Briggs-Rauscher (BR) oscillating system. In the system, macrocyclic nickel (II) complex NiL(ClO4)2 is used as the catalyst, where the ligand L in the complex is 5,7,7,12,14,14‑hexemethyl‑1,4,8,11‑tetraazacyclotetradeca‑4,11‑diene. By putting equal amount of the same concentrations of four isomers (1,4‑dihydroxynaphthalene (1,4-DHN), 1,5‑dihydroxynaphthalene (1,5-DHN), 2,3‑dihydroxynaphthalene (2,3-DHN) and 2,7‑dihydroxynaphthalene (2,7-DHN)) into BR system, the system could or couldn't be perturbed, being reflected in quite different oscillating behaviors after addition of isomers. These four isomers were identified in their concentration range of 5.0 × 10−6 to 2.5 × 10−4 mol/L. An explanation of such perturbation mechanism is that, 1,4-DHN couldn't be oxidized by BR matrix, but 1,5-DHN, 2,3-DHN and 2,7-DHN could be oxidized by HOO to yield 5‑Hydrox‑1,4‑naphthoquinone, phthalic acid and 6,7‑dihydroxyperylene‑1,12‑quinone (DHPQ), respectively.

Isomeric influences of naphthalene based sulfonated poly(arylene ether sulfone) membranes for energy generation using reverse electrodialysis and polymer electrolyte membrane fuel cell

Sulfonated poly(arylene ether sulfone) (SPAES) copolymers possessing three different dihydroxynaphthalene isomers and a biphenol (BP) moiety were synthesized as membranes for energy generation. Membrane samples of three different weight-based ion exchange capacities (IECw, 1.42, 1.82 and 2.2meqg−1) were evaluated through a thermal, mechanical and electrochemical analysis. In order to investigate the isomeric effects of naphthalene and BP units in a polymer matrix, their ion transport properties were studied for potential energy generation applications, exemplified by reverse electrodialysis (RED) and polymer electrolyte membrane fuel cell (PEMFC) applications. Interestingly, the prepared polymeric membranes comprised of three different naphthalene isomers or BP exhibited considerably disparate ion transport properties in both RED and PEMFC applications. In RED applications, 2,6-dihydroxynaphthalene containing SPAES showed high Na+ ion permselectivity and low membrane resistance due to the dense membrane structure and linear conformation of the resulting membrane. In addition, despite having the same IECw, a large difference in the electrochemical performance of the membranes was observed due to isomeric effects in the naphthalene containing polymer backbone. Moreover, in PEMFC single cell tests at 80°C under RH 100% and H2/air feed conditions, the membrane composed of 1,5-dihydroxynaphthalene (IECw=2.2meqg−1), which had a helical conformation, achieved a promising current density (614mAcm−2 at 0.6V) among the tested membranes.

Isomeric effect of sulfonated poly(arylene ether)s comprising dihydroxynaphthalene on properties for polymer electrolyte membranes

AbstractPolymer electrolyte membranes (PEMs) made of sulfonated poly(arylene ether)s consisted of 3,3′‐disulfo‐4,4′‐dichlorodiphenylsulfone disodium salt, 2,6‐dichlorobenzonitrile, and one of three dihydroxynaphthalene isomers (2,6‐, 2,7‐, and 1,5‐dihydroxynaphthalene, abbreviated as 2,6‐N, 2,7‐N, and 1,5‐N, respectively) were prepared with similar level of inherent viscosity and ion exchange capacity, and structural effect of the catenation in dihydroxynaphthalene isomers on membrane properties was compared. In the case of membranes for PEM fuel cell application with relatively high ion exchange capacity around 2.1 mequiv/g, three copolymers showed almost the same proton conductivity; however, swelling in water increased with the following order: 1,5‐N < 2,6‐N < 2,7N. In the case of direct methanol fuel cell membranes with lower ion exchange capacity around 1.5 mequiv/g, no remarkable difference in proton conductivity was also observed in three isomeric copolymers and swelling property and methanol permeability were lower in 1,5‐N and 2,6‐N copolymers than 2,7‐N copolymer. These tendencies show that higher rigidity or energy barrier for conformational change of polymer chain gives better performance of PEM for fuel cells with superior dimensional stability. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Crystal Engineering Approach To Design Colorimetric Indicator Array To Discriminate Positional Isomers of Aromatic Organic Molecules

Discriminating by color: A 2D colorimetric indicator array has been designed by a crystal engineering approach (NH-O hydrogen bonding and charge-transfer complexation) involving solid-state co-grinding for the visual discrimination of positional isomers of dihydroxynaphthalene. Factors governing the close packing of pi planes, and hence color of the complex, were determined by single-crystal X-ray analysis, allowing fine tuning by crystal engineering. A 2D colorimetric indicator array to discriminate isomers of dihydroxynaphthalene has been designed by using a crystal engineering concept combined with solid-state co-grinding and charge-transfer complexation. The NH-O supramolecular synthon between the pyridyl N atom of the probe and hydroxy group of the analyte has been observed in all reported single-crystal X-ray structures of resultant CT complexes. Solid-state co-grinding with aromatic solids easily provided the highly concentrated solvent-free conditions required to promote the formation of charge-transfer complexes with brighter color changes. Probe D (N,N'-bis-(4-pyridyl)pyromellitic diimide) showed an excellent ability to discriminate eight isomers of dihydroxynaphthalene with a wide variety of colors of the resultant CT complexes.

Spontaneous Colorimetric Sensing of the Positional Isomers of Dihydroxynaphthalene in a 1D Organogel Matrix

Like a color palette: A naphthalenediimide-based organogel colorimetric sensor allows recognition of the positional isomers of dihydroxynaphthalene in the gel phase with the naked eye. Intercalation of the dihydroxynaphthalene into the gel matrix produces a donor–acceptor interaction, which gives the gel a distinct color that depends on the strength of noncovalent (H-bonding, π-stacking, van der Waals) interactions. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z503158_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Spontaneous Colorimetric Sensing of the Positional Isomers of Dihydroxynaphthalene in a 1D Organogel Matrix

Spontaneous Colorimetric Sensing of the Positional Isomers of Dihydroxynaphthalene in a 1D Organogel Matrix

Evaluation of newly synthesized and commercially available charged cyclomaltooligosaccharides (cyclodextrins) for capillary electrokinetic chromatography

A highly new charged cyclodextrin (CD) derivatives, (6- O-carboxymethyl-2,3-di- O-methyl)cyclomaltoheptaoses (CDM-β-CDs), was synthesized and characterized as anionic reagents for capillary electrophoresis (CE) in an electrokinetic chromatography mode of separation. Substitution with dimethyl groups at the secondary hydroxyl sites of the CD is aimed at influencing the magnitude and selectivity of analyte–CD interactions, while substitution by carboxymethyl groups at the primary hydroxyl sites provides for high charge and electrophoretic mobility. Full regioselective methylation at the secondary hydroxyl sites was achieved in this work, while substitution at the primary hydroxyl sites generated a mixture of multiply charged products. The separation performance of CDM-β-CD was evaluated using a variety of analyte mixtures. The results obtained from commercially available negatively charged cyclodextrins, heptakis(2,3-di- O-methyl-6- O-sulfo)cyclomaltoheptaose (HDMS-β-CD) and O-(carboxymethyl)cyclomaltoheptaose (CM-β-CD) with an average degree of substitution one (DS 1), were compared to CDM-β-CD using a sample composed of eight positional isomers of dihydroxynaphthalene. Four hydroxylated polychlorobiphenyl derivatives, a group of chiral and isomeric catchecins, and chiral binaphthyl compounds were also separated with CDM-β-CD. The effect of adding neutral β-cyclodextrin (β-CD) into the running buffer containing charged cyclodextrins was investigated and provided evidence of significant inter-CD interactions. Under certain running buffer conditions, the charged cyclodextrins also appear to adsorb to the capillary walls to various degrees.

Evaluation of chemometric methods for determining the number and position of components in high-performance liquid chromatography detected by diode array detector and on-flow 1H nuclear magnetic resonance spectroscopy

Exploratory data analysis was performed on DAD-HPLC and on-flow HPLC-NMR data sets to determine the number of components (rank) in the mixture, and their elution times. The performance of principal component analysis, correlation plots, Euclidean distance, derivative plots, orthogonal projection approach, SIMPLISMA (SIMPLe-to-use Interactive Self-modelling Mixture Analysis) and evolving principal component analysis were compared on a mixture of three regio isomers of dihydroxynaphthalene. It was shown that derivatives and SIMPLISMA performed better with HPLC-NMR data than the other methods. OPA and evolving PCA performed best in DAD-HPLC. The relative performance of each chemometric method differs for each analytical technique, suggesting that criteria are dependent on instrumental method.

Synthesis and characterization of new poly(arylene ether 1,3,4-oxadiazole)s based on dihydroxynaphthalene isomers

A series of new poly(arylene ether 1,3,4-oxadiazole)s has been obtained starting from a difluorosubstituted monomer containing 1,3,4-oxadiazole rings and some dihydroxynaphthalene isomers. The polymers have been prepared by polycondensation in solution and have been obtained in quantitative yield. They had inherent viscosity from 0.2 to 0.82 dL/g, showed good thermal stability (10% weight loss temperatures in nitrogen and air were above 460 and 450°C, respectively) and high glass transition temperatures (in the range of 197–232°C). The polymers were characterized by elemental and infrared analyses, GPC and wide angle X-ray diffraction.

Metal-metal interactions as a function of bridging ligand topology: an electrochemical, spectroelectrochemical, and magnetic study on dinuclear Oxo-Mo(V) complexes with various isomers of dihydroxynaphthalene as bridging ligand.

Reaction of [MoV(TpMe,Me)(O)Cl2] with 1,3-, 1,5-, 1,6-, 2,6-, and 2,7-dihydroxynaphthalene affords the dinuclear complexes [[Mo(TpMe,Me)(O)Cl]2(mu-C10H6O2)], abbreviated as 1,3-Mo2, 1,5-Mo2, 1,6-Mo2, 2,6-Mo2, and 2,7-Mo2, according to the substitution pattern of the bridging ligand. Electrochemical, UV-vis/NIR spectroscopic, and variable-temperature magnetic susceptibility studies have been used to probe the effects of the bridging-ligand topology on the metal-metal electronic and magnetic interactions. The complexes can be split into two classes according to the properties of the bridging ligands. Complexes 1,3-Mo2, 1,6-Mo2, and 2,7-Mo2 all have bridging ligands that are topologically equivalent to meta-substituted bridging ligands such as 1,3-dihydroxybenzene, in that (i) there is an odd number of C atoms separating the two oxygen atoms, regardless of the pathway that is taken through the ligand skeleton, and (ii) the doubly oxidized from of the bridging ligand is a diradical. These complexes are classified as being "T-meta" (= topologically equivalent to meta). Complexes 1,5-Mo2 and 2,6-Mo2 have bridging ligands that are topologically equivalent to para-substituted groups such as 1,4-dihydroxybenzene, in that (i) there is an even number of C atoms separating the two oxygen atoms, whichever pathway is taken through the ligand skeleton, and (ii) the doubly oxidized form of the bridging ligand is a diamagnetic quinone. These complexes are classified as "T-para". Electrochemical studies show that the comproportionation constants for the Mo(V)/Mo(IV) mixed-valence states of the T-meta complexes are smaller than those for the T-para complexes. Spectroelectrochemical studies show that the Mo(V)/Mo(IV) mixed-valence states of the T-para complexes show pronounced Mo(IV)-->Mo(V) IVCT transitions, whereas those of the T-meta complexes do not show these transitions. Magnetic susceptibility studies show that the T-meta complexes all display ferromagnetic exchange between the metal centers, whereas the T-para complexes all display antiferromagnetic exchange. Thus, both the electronic and the magnetic properties of these complexes show a clear demarcation into two sets according to the bridging-ligand topology.

Synthesis and characterization of new poly(arylene ether)s based on dihydroxynaphthalene isomers

A series of new poly(arylene ether ketone)s and poly(arylene ether sulfone)s, obtained starting from dihydroxynaphthalene isomers, have been prepared by solution condensation polymerization. The polymers, having inherent viscosities from 0.20 to 0.77 dl g −1, have been obtained in quantitative yields, had excellent thermal stability as shown by 10% weight loss temperatures in nitrogen and air (above 460 and 430°C, respectively) and high glass transition temperatures (in the range 151–278°C). X-ray diffraction patterns confirmed the semicrystalline character of some polymers. The location of the naphthalene-ether bond appears to affect the polymer properties.

Determination of mercapturic acids using 1,4- dihydroxynaphthalene, a new matrix for matrix-assisted UV laser desorption/ionization mass spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF-MS) was applied for the characterization of six N-acetylcysteine conjugates (mercapturic acids) of synthetic origin. The measurement of mercapturic acids can provide important information for the biomonitoring of exposure to electrophilic compounds. Five isomers of dihydroxynaphthalene were evaluated as a MALDI matrix. 1,4-dihydroxynaphthalene was found to be very effective and the most suitable and was therefore used for further measurements. It has efficient absorbance at 337 nm, low background matrix ion signals and low matrix adduction. In the positive-ion mode only very weak signals were detected. In the negative-ion mode, the spectra exhibited deprotonated molecular ions [M – H] of high abundance and no adduct peaks or fragment ions were observed. This enabled reliable molecular mass determination of all six mercapturic acids. A detection limit of 1 pmol (signal-to-noise ratio = 3) applied to the target was achieved, which is distinctly more sensitive than other detection methods. In addition, the data obtained for intensities of the deprotonated molecular ion [M – H] enabled the recording of the degradation kinetics of solutions with two distinct pH values during five days. Among six investigated compounds, only one, 1,2-dihydroxy-4-(N-acetylcysteinyl)butane (DIOL), was found not to be stable in aqueous solution.

Synthesis of dihydroxynaphthalene isomers by microbial oxidation of 1- and 2-naphthol

The mutant strain Pseudomonas fluorescens TTC1 (NCIMB 40605), derived from the naphthalene-degrading Pseudomonas fluorescens N3 (NCIMB 40530), was used for the oxidation of 1- and 2-naphthols to give different isomers of dihydroxynaphthalene. The oxidation reactions proceed through the formation of dihydrodiol intermediates, which are too unstable to be isolated, since they spontaneously eliminate water to give the fully aromatic dihydroxynaphthalenes. The high regioselectivity of the dehydration reaction was confirmed by the study of the acid-catalysed aromatization of a series of stable monosubstituted naphthalene cis-1,2-dihydrodiols.

Mutagenicity of dihydroxybenzenes and dihydroxynaphthalenes for Ames Salmonella tester strains

The mutagenicity of 3 dihydroxybenzene (DHB) and 9 dihydroxynaphthalene (DHN) isomers was examined by using 5 different Ames Salmonella mutagenicity tester strains in the presence and absence of phenobarbital and 5,6-benzoflavonetreated rat liver S9-mix. Of the 3 DHB isomers, 1,4-DHB (hydroquinone) was mutagenic, and of the 9 DHN isomers, 1,3-DHN (naphthoresorcinol), 1,4-DHN (hydronaphthoquinone), 1,6-DHN and 1,7-DHN were mutagenic. Mutagenicity of all the compounds tested was observed in the absence of S9-mix, while 1,4-DHN and 1,6-DHN were also mutagenic in the presence of S9-mix. The mutagenicity of 1,4-DHB and 1,4-DHN for TA104, which is a strain sensitive to oxidative mutagens, was almost completely or partially inhibited by superoxide dismutase (SOD) and/or catalase, indicating the involvement of activated oxygen species in mutagenesis. Furthermore, from the finding that the 4 DHNs were mutagenic for TA2637, the strain sensitive to frameshift mutagens, it is possible that the mutagenicity of DHNs for S. typhimurium was also attributable to DNA adducts that form with quinones and/or semiquinones through oxidation of DHNs. The mutagenicity of 1,3-DHN, which showed the largest number of revertants in strains TA100, TA98, TA2637 and TA104, was greatly decreased, when their pKM101 plasmid-deficient strains, TA1535, TA1538, TA1537 and TA2659 were used. This observation suggests that an SOS repair system was involved in the mutagenesis of 1,3-DHN for S. typhimurium.

Gas transport properties of polysulfones based on dihydroxynaphthalene isomers

Naphtalene-based polysulfones have higher T g s than the polysulfones based on bisphenol A. The location of the naphtalene ether bond does not appear to dramatically affect the polymer properties, which is in contrast to the strong meta versus para effects observed in polymer chains having single rings in the backbone

Crystal and molecular structure of dihydroxynaphthalene isomers. Effect of structure on ice-forming properties

Crystal and molecular structure of dihydroxynaphthalene isomers. Effect of structure on ice-forming properties