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The 1-naphthol·cyclopropane intermolecular complex is formed in a supersonic jet and investigated by resonant two-photon ionization (R2PI) spectroscopy, UV holeburning, and stimulated emission pumping (SEP)-R2PI spectroscopy. Two very different structure types are inferred from the vibronic spectra and calculations. In the "edge" isomer, the OH group of 1-naphthol is directed towards a C--C bond of cyclopropane, the two ring planes are perpendicular. In the "face" isomer, the cyclopropane is adsorbed on one of the π-aromatic faces of the 1-naphthol moiety, the ring planes are nearly parallel. Accurate ground-state intermolecular dissociation energies D0 were measured with the SEP-R2PI technique. The D0(S0) of the edge isomer is bracketed as 15.35 « 0.03 kJ/mol, while that of the face isomer is 16.96 « 0.12 kJ/mol. The corresponding excited-state dissociation energies D0(S1) were evaluated using the respective electronic spectral shifts. Despite the D0(S0) difference of 1.6 kJ/mol, both isomers are observed in the jet in similar concentrations, so they must be separated by substantial potential energy barriers. Intermolecular binding energies, De, and dissociation energies, D0, calculated with correlated wave function methods and two dispersion-corrected density-functional methods are evaluated in the context of these results. The density functional calculations suggest that the face isomer is bound solely by dispersion interactions. Binding of the edge isomer is also dominated by dispersion, which makes up two thirds of the total binding energy. [ABSTRACT FROM AUTHOR]

The fourier transform infrared (FT‒IR) and fourier transform Raman (FT‒Raman) spectra of l-hydroxy-2-naphthoic acid (1H2NA) in solid phase have been experimentally recorded and analyzed in the region 4000-400 cm-1. DFT/B3LYP/6-31G (d,p) calculations were used to determine the optimized molecular structure, conformational, non-linear optical (NLO), natural bond orbital (NBO) analysis, molecular surfaces, Mulliken, NBO charges and vibrational studies of 1H2NA. Obtained results on the geometric structure, vibrational frequencies and UV-Vis spectral analysis are compared with the observed data. The dimeric structure of 1H2NA with the DFT/B3LYP/6-31G (d,p) level caused by the shifts of O-H and C=O bands in the vibrational spectra were also studied. Moreover, the spectroscopic and theoretical results were compared with the corresponding properties for monomeric and dimeric structures of 1H2NA. The detailed vibrational assignments were performed with the DFT calculation, and the potential energy distribution (PED) was obtained by the vibrational energy distribution analysis (VEDA4) program. TD-DFT/B3LYP/6-31G (d,p) calculations with the SCF (self-consistent field) in gas phase and ethanol solvent in the excited state were employed to investigated UV-Vis absorption spectra and the major contributions to the electronic transitions were obtained. The NLO properties such as mean polarizability (<α>), the anisotropy of the polarizability (<Δα>) and the mean first-order hyperpolarizability (<β>) were computed by using finite field method. The computed values of μ, α and β of the title molecule are 2.2744 D, 17.3225 × 10-24 esu and 4.222 × 10-30 esu, respectively. The high β values and non-zero values of μ indicate that the title compound might be a good candidate for NLO material. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A series of pyrazole linked benzothiazole-β-naphthol derivatives were synthesized by using catalyst-free reaction conditions. • The synthesized derivatives were tested for their anti-proliferative activity against human cancer cell lines. • Topoisomerase I inhibition assay demonstrates that these derivatives inhibit topoisomerase I activity. • Spectroscopic studies and molecular docking studies revealed that these derivatives exhibit DNA minor groove binding. Abstract A series of new pyrazole linked benzothiazole-β-naphthol derivatives were designed and synthesized using a simple, efficient and ecofriendly route under catalyst-free conditions in good to excellent yields. These derivatives were evaluated for their cytotoxicity on selected human cancer cell lines. Among those, the derivatives 4j , 4k and 4l exhibited considerable cytotoxicity with IC 50 values ranging between 4.63 and 5.54 µM against human cervical cancer cells (HeLa). Structure activity relationship was elucidated by varying different substituents on benzothiazoles and pyrazoles. Further, flow cytometric analysis revealed that these derivatives induced cell cycle arrest in G2/M phase and spectroscopic studies such as UV–visible, fluorescence and circular dichroism studies showed that these derivatives exhibited good DNA binding affinity. Additionally, these derivatives can effectively inhibit the topoisomerase I activity. Viscosity studies and molecular docking studies demonstrated that the derivatives bind with the minor groove of the DNA. [ABSTRACT FROM AUTHOR]

Aminobenzylnaphthols are a class of compounds containing a large aromatic molecular surface which makes them suitable candidates to study the role of C—H...π interactions. We have investigated the effect of methyl or methoxy substituents on the assembling of aromatic units by preparing and determining the crystal structures of (S,S)‐1‐{(4‐methylphenyl)[(1‐phenylethyl)amino]methyl}naphthalen‐2‐ol, C26H25NO, and (S,S)‐1‐{(4‐methoxyphenyl)[(1‐phenylethyl)amino]methyl}naphthalen‐2‐ol, C26H25NO2. The methyl group influenced the overall crystal packing even if the H atoms of the methyl group did not participate directly either in hydrogen bonding or C—H...π interactions. The introduction of the methoxy moiety caused the formation of new hydrogen bonds, in which the O atom of the methoxy group was directly involved. Moreover, the methoxy group promoted the formation of an interesting C—H...π interaction which altered the orientation of an aromatic unit. Aminobenzylnaphthol derivatives are suitable systems to study the fundamental role of C—H...π interactions in controlling the crystal packing of small molecules. [ABSTRACT FROM AUTHOR]

Highlights • Effect of solvents on the photophysical properties of 1-naphthol-4-sulfonate photoacid. • Effect of Specific versus non-specific solute-solvent interactions on the photophysical properties. • Effect of inclusion in different cyclodextrins on the photophysical properties. • Determination of the association constant using steady state and time resolved fluorescence spectroscopy. • Effect of cavity dimension and hydrophobicity on the inclusion of guest molecules. Abstract Photophysical properties of the ground and excited states of 1-naphthol-4-sulfonate (1NO4S), photoacid, are investigated in different solvents and cyclodextrin derivatives of different size and structure. Fluorescence decay traces of 1NO4S are well fitted to double exponential decay function in all solvents. The short-lived traces with higher amplitude were assigned to emission of the neutral form (ROH*), while the long-lived traces with low amplitude were assigned to emission of the anionic form (RO−*). The photophysical properties of 1NO4S were correlated with a number of solvent parameters such as the solvent polarity parameters E T N and the reaction field factor Δ f. Three linear solvation energy relationships developed by Kamlet-Taft, Catalán, and Laurence et al. were employed to assess the effect of non-specific and specific interactions on the photophysical properties of 1NO4S. All three solvation energy relationships showed that the non-specific interactions mainly control the photophysical properties of 1NO4S while the contribution of the specific interactions are weak. Molecular encapsulation of 1NO4S by α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), methyl-β-cyclodextrin (Mβ-CD), 2-hydroxypropyl-β-cyclodextrin (HPβ-CD) in aqueous solution has been studied by steady state and time resolved fluorescence techniques. Steady state fluorescence measurements show 1:1 inclusion of 1NO4S with different cyclodextrin derivatives with an association constant of 7.9 ± 4.0, 59.6 ± 10.0, 0.4 ± 0.5, 169.8 ± 25.0, and 359.0 ± 20.0 M−1 for 1NO4S complexes with α-CD, β-CD, γ-CD, Mβ-CD or HPβ-CD, respectively following the fluorescence intensity changes of the anionic form (RO−*) at 435.0 nm. Association constants obtained following the fluorescence enhancement of the neutral form (ROH*) were the same as determined following fluorescence intensity decrease of RO−* at 372 nm. Data derived from time resolved measurements gave very close value for the association constants as determined from steady state fluorescence measurements. [ABSTRACT FROM AUTHOR]

Abstract: A novel, simple, and efficient protocol is described for the synthesis of 1-alkyl-2-(aryloxy)methyl-1H-pyrrolo[2,3-b]quinoxalines via the one-pot reaction of phenol or 2-naphthol derivatives, propargyl bromide, and N-alkyl-3-chloroquinoxaline-2-amines in the presence of palladium catalyst. This one-pot reaction is carried out in the absence of any copper salt at room temperature. The reaction product is dependent on the nature of the base used. The use of morpholine, as the base, affords the final cyclized product, and triethylamine only gives the coupling product.Graphical abstract: [ABSTRACT FROM AUTHOR]

Highlights • 1,2,3,4,4a,5,6,7-Octahydro-2,5,5-trimethyl-2-naphthalenol, safety assessment based on RIFM's criteria. • Safety assessment based on 7 human health endpoints plus environmental. • All endpoints were cleared using target data, read-across, and/or TTC. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Lignin modification was performed by adding naphthol derivatives in the pretreatment. • The addition of naphthol derivatives enhanced the enzymatic hydrolysis. • 2-Naphthol-7-sulfonate was more effective than 2-naphthol. • The enzyme non-productive binding was reduced with 2-naphthol-7-sulfonate addition. • 2-Naphthol-7-sulfonate suppressed the lignin condensation during the pretreatment. Abstract Effects of the addition of 2-naphthol and 2-naphthol-7-sulfonate on the dilute acid pretreatment of mixed wood sawdust were investigated, respectively. Compared to 2-naphthol, 2-naphtnol-7-sulfonate was more effective to enhance delignification and facilitate the enzymatic hydrolysis. The 72 h hydrolysis yield was improved by 47.8% for 2-naphthol-7-sulfone, while only 9.1% was observed for 2-naphthol. The surface charges, enzyme adsorption, and cellulose accessibility of dilute acid pretreated substrates with or without naphthol derivatives were examined. The improved enzymatic hydrolysis by adding 2-naphthol-7-sulfonate was ascribed to the higher negative surface charges, the lower enzyme non-productive binding, and the higher cellulose accessibility of pretreated substrates. Additionally, the HSQC NMR and 31P NMR analysis were carried out on both decomposed lignins and residual bulk lignins. It indicated that the addition of the naphthol derivatives during pretreatment could suppress the lignin repolymerization, which further mitigated the inhibition of residual lignins on enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

Nitroallylic acetates react with naphthols and electron‐rich phenols under mild conditions (TEA, DCM, room temp.) to afford arenopyrans in moderate to excellent yields. Such (3+3) annulation of a 1,3‐bielectrophilic nitroallylic acetate and a 1,3‐binucleophilic arenol involving an SN2′ reaction and an intramolecular 6‐endo‐trig cyclization takes place in a regio‐ and stereoselective manner. Surprisingly, the reaction of arenethiols under the same conditions provided nitroallylic thioethers instead of the expected arenothiopyrans presumably through a direct SN2 reaction. (3+3) Annulation of a 1,3‐bielectrophilic nitroallylic acetate and a 1,3‐binucleophilic arenol involving an SN2′ reaction and an intramolecular 6‐endo‐trig cyclization takes place in a regio‐ and stereoselective manner to provide arenopyrans. Interestingly, the reaction of arenethiols under the same conditions provided nitroallylic thioethers through a direct SN2 reaction. [ABSTRACT FROM AUTHOR]

The reaction of bis(diethylamino)phosphoryl chloride with N-Boc-protected 1-(α-aminobenzyl)-2- naphthol (Betti base) proceeded via O-phosphorylation of the phenolic OH group to form the target product as trifluoroacetate salt. The latter reacted with O,O-diethyl thiophosphorylisothiocyanate to give thiourea bearing a chiral Betti base fragment. [ABSTRACT FROM AUTHOR]

In this study, [H2-DABCO][HSO4]2 is applied as an acidic ionic liquid to exclude some disadvantages of former methods reported for the synthesis of 3-amino-1-aryl-1H-benzo[f]chromene-2-carbonitrile, 1-(benzothiazolylamino)phenylmethyl-2-naphthol, and 1-(benzoimidazolylamino)phenylmethyl-2-naphthol derivatives. In the presence of this catalyst, all reactions are performed under neat conditions during short reaction times in good-to-high yields. Ease of preparation and recyclability of the catalyst are the other important advantages of this method. [ABSTRACT FROM AUTHOR]

Abstract: The first visible‐light‐promoted dearomative fluoroalkylation of β‐naphthols was realized without the assistance of any transition‐metal catalysts or external photosensitizers. Inexpensive fluoroalkyl iodides were directly used as efficient fluoroalkylation reagents under very mild reaction conditions. The scope of this process was found to be general and broad, and both trifluoromethyl and perfluoroalkyl groups (‐C4F9, ‐C6F13, and ‐C8F17) were installed in excellent yields. Preliminary mechanistic studies suggest that visible‐light‐promoted intermolecular charge transfer within the naphtholate–fluoroalkyl iodide electron donor–acceptor (EDA) complex induces a single electron transfer in the absence of photocatalysts. [ABSTRACT FROM AUTHOR]

Nine heterocyclic and aromatic azo derivatives of phenol and 1-naphthol were studied as flotation collectors of sulfide ores of non-ferrous metals. The constants of acid dissociation of compounds in aqueous solutions and their solubility in alkaline media are determined. It has been established that the adsorption of reagents on the surface of sulfide copper-nickel ore has a physical character. The adsorption constants are calculated. It is shown that the reagents under study exhibit collective properties with respect to the sulfide minerals of copper, cobalt and nickel. The use of mixtures of azo compounds with potassium butyl xanthate leads to an increase in both the recovery degree and the quality of the concentrate for nickel and copper in comparison with a single butyl xanthate. [ABSTRACT FROM AUTHOR]

One-pot sequential reactions using the acyl moieties installed by enzymatic dynamic kinetic resolution of alcohols have been little investigated. In this work, the acryloyl moiety installed via the lipase/oxovanadium combo-catalyzed dynamic kinetic resolution of a racemic dienol [4-(cyclohex-1-en-1-yl)but-3-en-2-ol or 1-(cyclohex-1-en-1-yl)but-2-en-1-ol] with a ( Z )-3-(phenylsulfonyl)acrylate underwent an intramolecular Diels–Alder reaction in a one-pot procedure to produce an optically active naphtho[2,3- c ]furan-1(3 H )-one derivative (98% ee). This method was successfully applied to the asymmetric total synthesis of (−)-himbacine. [ABSTRACT FROM AUTHOR]

A total of four new metal complexes derivatives of 1-( 2- hydroxyl- 4--nitrophenylazo) -2-naphthol with the metal ions Co(II), Fe(III), Cu(II) and Zn(II) have been successfully prepared in alcoholic medium. The ligand and complexes obtained are characterized qualitatively using FTIR spectroscopy, UV- Vis spectroscopy and chromatography measurements. The ligand gave retention time 3.225 min while the complexes with Cu &Ag show retention time 3.474min ,3.774 min respectively .From the spectral study, all the complexes obtained as monomeric structure and the metals center moieties are five or six-coordinated with Octahedral geometry. The preliminary in vitro the biological study of ligand and their complexes against selected types of bacteria such as; Escherichia coli, Streptococcus mutans, Proteus bacilli and Staphylococcus, the antibacterial screening activity revealed that the ligand and their complexes showed moderate activity against all tested bacterial strains except Streptococcus mutans. [ABSTRACT FROM AUTHOR]

A fast, simple, and economical method for extraction, preconcentration and determination of cobalt, nickel and copper as their 1-(2-pyridilazo) 2-naphthol (PAN) complexes based on ultrasound-assisted emulsification-microextraction (USAEME) and multivariate calibration of spectrophotometric data is presented. Various parameters affecting the extraction efficiency were optimized both with univariate and Box-Behnken design. The resolution of ternary mixtures of these metallic ions was accomplished by using partial least-squares regression (PLS), orthogonal signal correction- partial least-squares regression (OSC-PLS), and orthogonal signal correction- genetic algorithmspartial least-squares regression (OSC-GA-PLS). Under the optimum conditions, the calibration graphs were linear in the range of 2.0-150.0, 2.0-120.0 and 2.0-150.0 ng mL-1 for Co2+, Ni2+, and Cu2+, respectively, with a limit of detection of 0.14 (Co2+), 0.13 (Ni2+) and 0.14 ng mL-1 (Cu2+) and the relative standard deviation was <2.5%. The method was successfully applied to the simultaneous determination of these cations in different samples. [ABSTRACT FROM AUTHOR]

A naphthol derivative ( E )-1-((2-(benzo[d]thiazol-2-yl)hydrazono)methyl)naphthalen-2-ol (NABT) exhibits an “off–on-type” fluorescent chemosensing for the detection of Al 3+ ions, due to chelation-enhanced fluorescence (CHEF). The fluorescence intensity at 515 nm (excitation at 420 nm) of NABT increases about 42-fold upon addition of 20 equivalent Al 3+ . Moreover, the binding details of NABT with Al 3+ were determined by 1 H NMR and ESI-MS studies. The NABT interacts with Al 3+ in a tridentate mode to form [Al(NABT)(DMSO)], [Al(NABT)Cl(DMSO)], [Al(NABT)(DMSO) 2 ] and [Al(NABT) 2 ] complexes. The addition of EDTA to NABT–Al 3+ complex quenches the fluorescent intensity, indicating that NABT could serve as a reversible chemosensor. [ABSTRACT FROM AUTHOR]

The IR and Raman spectra of the 4-chloro-1-naphthol (4C1N) recorded for a solid phase, in the range 4000–500 cm −1 and 4000–100 cm −1 respectively, are compared with the results of DFT B3LYP/6-311 + G(3d,2p) calculations. Theoretical spectra, after standard scaling procedure, fit the experimental ones very well – RMS are 7.61 cm −1 and 4.98 cm −1 . PED analysis allows to the description of the observed vibrations. A location and character of the particular deformations agree well with those reported for the similar aromatic compounds. A UV-VIS spectrum recorded for a 4C1N solution in tetrahydrofuran is perfectly reproduced by TD-DFT calculations results with the same functional and basis set as indicated above. On the other hand, MP2-CIS results work very badly. The calculated values of the components of the polarizability and two first hyperpolarizabilities ( β , γ ) tensors, significantly greater than these for urea, reveal that 4C1N may be considered as promising NLO material. [ABSTRACT FROM AUTHOR]

TiO 2 -P25 supported Pd/C (P25@Pd/C) composite was prepared by the solid state dispersion method. The prepared composite was characterized by XRD, Raman, PL, SEM and DRS measurements. The photocatalytic activity of the composite was tested towards Naphthol Blue Black (NBB) azo dye degradation under visible light. The photocatalytic activity of P25 was highly influenced by Pd/C. Almost complete degradation was achieved with P25@Pd/C in 120 min, and found to be more efficient when compared with pristine Degussa-P25. The composite was reused in four cycles without loss of activity. A mechanism was proposed for NBB degradation by P25@Pd/C composite under visible light. [ABSTRACT FROM AUTHOR]

Sodium 1-[1-hydroxynaphthylazo]-6-nitro-2-naphthol-4-sulfonate dye (EBT) was studied as sensitizers with regard to colloidal ZnO nanocrystalline. The interaction between EBT and colloidal ZnO nanoparticles has been examined by using several spectroscopic techniques, e.g., steady-state absorption and fluorescence, cyclic voltammetry, and fourier-transform infrared. The results showed that the adsorption of EBT occurs on the surface of colloidal ZnO nanoparticles by way of using electrostatic interaction. This adsorption leads to the growth in optical density and quenching of the emission intensity of dye molecules. The fluorescence quenching is fundamentally attributed to electron transfer from an excited dye state to the conduction band of colloidal zinc oxide (EBT ∗ → Zn 3d ). [ABSTRACT FROM AUTHOR]

Copyright of Al-Qadisiyah Journal of Pure Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two series of novel 2-arylvinyl-naphtho[2,3- d ]imidazol-3-ium iodide derivatives and 2-arylvinyl-naphtho[2,3- d ]imidazol-3-ium bromide derivatives were designed and synthesized by the structural combination of YM155 with stilbenoids. All compounds were tested for anti-proliferative activity against PC-3, A375 and HeLa human cancer cell lines. Two of the compounds were selected for further investigation: 12b, which showed potent cytotoxicity against the three tested cell lines with IC 50 values in the range of 0.06–0.21 μM, and 7l , which displayed excellent selectivity for PC-3 cells with an IC 50 of only 22 nM. Western blot analysis results indicated that both 12b and 7l suppress the expression of Bcl-2 and Survivin proteins, which helps induce apoptosis. As determined by the percent of Annexin V-FITC-positive apoptotic cells, 12b was not only significantly more effective than 7l at a concentration of 100 nM in PC-3 cells but also induced apoptosis in a dose-dependent manner with more potency than 7l at a concentration of 1000 nM in A375 cells. Therefore, compound 12b was chosen for further in-depth studies investigating the mechanism of apoptosis. The results showed that it could activate caspase-3, hydrolyze PARP, and even inactivate ERK. Moreover, 12b arrested A375 cells at S phase in a time-dependent and dose-dependent manner, while having a visible effect on microtubule dynamics. In addition, ( E )-2-(2-(1 H -indol-3-yl)vinyl)-1-benzyl-3-(2-methoxyethyl)-4,9-dioxo-4,9-dihydro-1 H -naphtho[2,3-d]imidazol-3-ium bromide ( 12b ) exhibited significant antitumor activity when evaluated in a subcutaneous solid tumor model. Our study reveals that 2-arylvinyl-substituted naphtho[2,3-d]imidazolium scaffolding is a promising new entity for the development of multi-target anticancer drugs. [ABSTRACT FROM AUTHOR]

As efficient electron transfer mediator, various nanomaterials with smart performance have been explored in non-enzymatic sensor fabrication. We herein present an electron transfer mediator actuated electrochemical non-enzymatic sensor to assay nitrite, enabled by electrochemical reduced graphene oxide (ERGO) and 1-(2-pyridylazo)-2-naphthol (PAN). The composites of PAN-ERGO coating on electrode surface were successfully fabricated through a facile and green cyclic voltammetry technique. With the aid of ERGO nanosheets on the electrode surface, the electron transfer mediator of PAN nanostructures was easily immobilized and hybridized with ERGO, resulting in a remarkably synergistic effect between ERGO sensing substrate and the electrodeposited PAN coating for target electron transfer. The results demonstrated that the electrocatalytic current increased linearly with the nitrite concentration in the range of 7.49–1752.6 μM and 1752.6–3500 μM, with a good detection limit of 0.67 μM and 1.44 μM (signal-to-noise ratio, S/N = 3), respectively. The present work provide some new insights for the smart design of high efficiency electrocatalytic materials that based on the composites of electrochemical reduced graphene oxide and other substances. [ABSTRACT FROM AUTHOR]

A highly diastereoconvergent Friedel–Crafts alkylation reaction of 2-naphthol derivatives with diastereomixtures of diarymethanols bearing a designed chiral auxiliary was achieved by using tin(IV) bromide as a catalyst in nitromethane under mild reaction conditions. The effects of various substituents located on the chiral auxiliary were evaluated, and chiral induction was found to take place via a carbocation through the chelation effect of an oxygen atom in a stereoconvergent manner. The chiral auxiliary was easily deprotected under conventional hydrogenation conditions without affecting the chirality of the starting material. A variety of substrates were transformed successfully, with high yields and selectivities (diastereomeric ratios ≥ 20:1) obtained irrespective of the substitution pattern and the electronic nature of the substrate aromatic rings. [ABSTRACT FROM AUTHOR]

A highly diastereoconvergent Friedel–Crafts alkylation reaction of 2-naphthol derivatives with diastereomixtures of diarymethanols bearing a designed chiral auxiliary was achieved by using tin(IV) bromide as a catalyst in nitromethane under mild reaction conditions. The effects of various substituents located on the chiral auxiliary were evaluated, and chiral induction was found to take place via a carbocation through the chelation effect of an oxygen atom in a stereoconvergent manner. The chiral auxiliary was easily deprotected under conventional hydrogenation conditions without affecting the chirality of the starting material. A variety of substrates were transformed successfully, with high yields and selectivities (diastereomeric ratios ≥ 20:1) obtained irrespective of the substitution pattern and the electronic nature of the substrate aromatic rings. [ABSTRACT FROM AUTHOR]

A metal-free [2+2] cycloaddition and 1,4-addition sequence induced by S-centered radicals has been achieved by treating benzene-linked allene-ynes with aryldiazonium tetrafluoroborates and DABCO-bis(sulfur dioxide) in a one-pot procedure. The reaction provides a greener and more practical access to functionalized cyclobuta[a]naphthalen-4-ols with valuable applications. More than 50 examples are demonstrated with excellent diastereoselectivity and chemical yields. The reaction pathway is proposed to proceed by the following steps:[2+2] cycloaddition, insertion of SO2, 1,4-addition, diazotization, and tautomerization. [ABSTRACT FROM AUTHOR]

The reaction of 2-acetyl- and 2-benzoyl-1,4-naphthoquinone with (Z)-methyl 3-(hydroxymethyl)aminocrotonate proceeds through a formal [3+3] process to yield the corresponding 1,2-dihydrobenzisoquinolinequinones in 63% and 72% yield, respectively. The reactions of 2-acyl-1,4-naphthoquinone with enaminones, derived from diverse L- and D-amino acid methyl esters, produced the corresponding naphthoquinone amino acids conjugates bonded through a vinyl spacer in the yields range 40-71%. The presence of not-separable isomers of the naphthoquinone amino acids conjugates in the ¹H- and 13C-NMR spectra is explained by the existence of conformational isomers generated by hindered rotation of the substituent bonded to the quinone double bond. These new naphthoquinone amino acids conjugates were screened in vitro on normal and cancer cell lines and showed moderate cytotoxic activities. [ABSTRACT FROM AUTHOR]

SUMMARY Contact doping effects in p-channel dinaphthothienothiphene (DNTT) thin-film transistors with a bottom-gate, top-contact configuration were investigated with both experimental and numerical approach. Characteristic variation in transistor parameters such as the gate threshold voltage and the field-effect mobility for devices with various channel lengths was suppressed by the contact doping with tetrafluorotetracyanoquinodimethane (F4TCNQ) as an acceptor dopant. The gate-voltage dependence of contact resistance and channel resistance was also evaluated separately to examine the contact doping effect in detail. In addition, device simulation considering a Schottky barrier at a metal/semiconductor interface successfully reproduced the experimental current-voltage characteristics by using a hole concentration of the active DNTT layer in the order of 1017 cm−3, which was estimated by capacitance-voltage measurement for a metal/insulator/semiconductor capacitor structure. This study suggests the importance of establishing both the carrier doping and carrier concentration measurements toward realizing practical applications of organic transistors. [ABSTRACT FROM AUTHOR]

N-Boc ketimines derived from pyrazolin-5-ones were explored to develop an unprecedented domino aza-Friedel-Crafts/N,O-acetalization reaction with 2-naphthols. The novel method requires a catalyst loading of only 0.5 mol % of a bifunctional squaramide catalyst, is scalable to gram amounts, and provides a new series of furanonaphthopyrazolidinone derivatives bearing two vicinal tetra-substituted stereogenic centers in excellent yields (95-98 %) and stereoselectivity (>99:1 d.r. and 97-98 % ee). A different reactivity was observed in the case of 1-naphthols and other electron-rich phenols, which led to the aza-Friedel-Crafts adducts in 70-98 % yield and 47-98 % ee. [ABSTRACT FROM AUTHOR]

2-Naphthol substituted Mannich base 1-morpholino(phenyl)methyl)naphthalen-2-ol (MPMN), a potential NLO active organic single crystal was developed using acetonitrile as a solvent by slow evaporation method. The experimental and theoretical analysis made towards the exploitation in the field of electro-optic and NLO applications. The cubic structure with non-centrosymmetric space group Cc was confirmed and cell dimensions of the grown crystal were obtained from single crystal X-ray diffraction (XRD) study. The formation of the C N C vibrational band at 1115 cm −1 in Fourier Transform Infra-Red (FTIR) analysis confirms the formation of MPMN compound. The placement of protons and carbons of MPMN were identified from Nuclear Magnetic Resonance Spectroscopy (NMR) analysis. The wide optical absorption window and the lower cutoff wavelength of MPMN show the suitability of the material for the various laser related applications. The presence of dislocations and growth pattern of crystal were analyzed using chemical etching technique. The Second Harmonic Generation (SHG) of MPMN was found to be 1.57 times greater than the standard KDP crystal. The laser damage threshold was measured by using Nd: YAG laser beam passed through the sample and it was found to be 1.006 GW/cm 2 . The electronic structure of the molecular system and the optical properties were also studied from quantum chemical calculations using Density Functional Theory (DFT) and reported for the first time. [ABSTRACT FROM AUTHOR]

In this study, experimental techniques such as Raman and infrared vibrational analysis and X-ray crystal diffraction were used to characterize three new azo chelate dyes derived from 1-phenyl-azo-2-naphthol (Sudan I) and its analogue 1-(xylylphenylazo)-2-naphthol (Sudan II) with metal ions. The Raman and infrared spectroscopic analysis have also provided useful information concerning the coordination and formation of the molecular complexes through their main bands. In the vibrational spectra, the fingerprint bands, such as the ones at 1369/1368/1359 cm −1 assigned to [ν(CC) + δ(CH)], ν(C N)], 1351/1352/1338 cm −1 assigned to [δ(CH)] and 816/824/813 cm −1 assigned to [ω(CH)] respectively for the SD1Cu, SD1Co and SD2Ni, can be used to characterize such compounds. [ABSTRACT FROM AUTHOR]

A Rh(III)-catalyzed multiple C-H bond activation/cyclization of phenol derivatives with alkynes was developed. Polyaryl-substituted naphthol derivatives, potentially useful as organic optoelectronic materials, were obtained in moderate to good yields. [ABSTRACT FROM AUTHOR]

The reaction of naphtho[2,1-b]furan-2-carbohydrazide 4 on treatment with chloroacetyl chloride in acid media afforded N'-(chloroacetyl)naphtho[2,1-b]furan-2-carbohydrazide 5. This on treatment with various aryl amines in DMF produced N'-(arylaminoacetyl)naphtho[2,1-b]furan-2-carbohydrazides 6a-f. The structures of 5 and 6a-f have been established by spectral studies. In addition the synthesised compounds have been screened for antimicrobial activities. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of the 3-(4-N-pyridine-2-yl benzene sulfonamide azo)-1-nitroso naphthol reagent and its complex with Co (II) has been studied at glassy carbon disk electrode in different supporting electrolyte at concentration 1 mol and scan rate (100 mV/s). 3-(4-N-pyridine-2-yl benzene sulfonamide azo)-1-nitroso naphthol was used for enhance the properties of nano cobalt oxide by ligand exchange reaction on nanoparticles. [ABSTRACT FROM AUTHOR]

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Background: Protein tyrosine phosphatases (PTPs) like dual specificity phosphatase 5 (DUSP5) and protein tyrosine phosphatase 1B (PTP1B) are drug targets for diseases that include cancer, diabetes, and vascular disorders such as hemangiomas. The PTPs are also known to be notoriously difficult targets for designing inihibitors that become viable drug leads. Therefore, the pipeline for approved drugs in this class is minimal. Furthermore, drug screening for targets like PTPs often produce false positive and false negative results. Results: Studies presented herein provide important insights into: (a) how to detect such artifacts, (b) the importance of compound re-synthesis and verification, and (c) how in situ chemical reactivity of compounds, when diagnosed and characterized, can actually lead to serendipitous discovery of valuable new lead molecules. Initial docking of compounds from the National Cancer Institute (NCI), followed by experimental testing in enzyme inhibition assays, identified an inhibitor of DUSP5. Subsequent control experiments revealed that this compound demonstrated time-dependent inhibition, and also a time-dependent change in color of the inhibitor that correlated with potency of inhibition. In addition, the compound activity varied depending on vendor source. We hypothesized, and then confirmed by synthesis of the compound, that the actual inhibitor of DUSP5 was a dimeric form of the original inhibitor compound, formed upon exposure to light and oxygen. This compound has an IC50 of 36 µM for DUSP5, and is a competitive inhibitor. Testing against PTP1B, for selectivity, demonstrated the dimeric compound was actually a more potent inhibitor of PTP1B, with an IC50 of 2.1 µM. The compound, an azo-bridged dimer of sulfonated naphthol rings, resembles previously reported PTP inhibitors, but with 18-fold selectivity for PTP1B versus DUSP5. Conclusion: We report the identification of a potent PTP1B inhibitor that was initially identified in a screen for DUSP5, implying common mechanism of inhibitory action for these scaffolds. [ABSTRACT FROM AUTHOR]

This study was aimed at the investigation of Rare Earth Element (REE) recovery from aqueous solution by silica gels with 1-(2-Pyridylazo) 2-naphthol (PAN) and acetyl acetone (Acac) modifications. The two different methods of silica gel chelation, such as chemical immobilization with the help of silane coupling agents (3-aminopropyl triethoxysilane (APTES) and 3-aminopropyl trimethoxysilane (APTMS) in this study) and direct physical adsorption onto the silica surface, is compared in terms of their REE removal efficiency. A comparative analysis between adsorption of different REEs for different silica gels is performed and the influence of parameters such as pH, contact time, temperature and initial concentration has been reported. The effect of calcined adsorbents on the adsorption process is also investigated. Characterization studies on silica gels by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD) and zeta potential analysis are performed to better understand the relation between physical/chemical attributes of the adsorbents and their impact on the adsorption process. The experimental results are evaluated and optimal conditions for REE adsorption are identified. Chemically immobilized gels demonstrated immense potential for all the REE under study except Sc, for which, physically loaded gels seemed to be more efficient. The removal of REEs could be achieved at lower pHs by chemically immobilized PAN/Acac gels, making it suitable for many practical applications. The amine functionalized gels before chemical immobilization step were compared with PAN/Acac chemically immobilized gels in single as well as multi element system and the significance of chemical immobilization after amine functionalization is also stated. [ABSTRACT FROM AUTHOR]

The naphthol derivative ( E )- N ′-((2-hydroxynaphthalen-1-yl)methylene)-1 H -indole-2-carbohydrazide ( 1 ) has been synthesized and characterized. Sensor 1 binds selectively with CN − ion in DMSO/H 2 O (7:3 v/v) mixed solvent medium with significant change in its UV–vis spectrum and detection limit of 1.2 μM. Sensor 1 shows dual emission bands at 335 nm and 460 nm due to naphthalene and excited state deprotonation of naphthalene OH group, respectively. Upon addition of CN − ion to 1 , fluorescence is turned on for the emission band at 460 nm with slight red-shift and fluorescence enhancement of 5.5 times. 1 undergoes binding followed by deprotonation of OH on titration with CN − ion, as supported by 1 H NMR titration. Solution of 1 in DMSO/H 2 O (7:3 v/v) exhibits considerable change in colour from colourless to yellow in visible light and green in long wavelength UV light (350 nm) upon addition of CN − ion selectively. Same visual colour change of 1 is observed on Whatman filter paper testing strips when it is impregnated on testing strips and immersed in CN − ion solution (DMSO/H 2 O, 7:3 v/v). 1 is used as a live cell imaging reagent for intra-cellular detection of CN − ion in A549 cells. [ABSTRACT FROM AUTHOR]

The photoinduced regio- and enantioselective coupling of naphthols and derivatives thereof is achieved in the confined chiral coordination space of a RuII metalloligand based cage. The racemic or enantiopure cages encapsulate naphthol guests, which then undergo a regiospecific 1,4-coupling, rather than the normal 1,1-coupling, to form 4-(2-hydroxy-1-naphthyl)-1,2-napthoquinones; moderate stereochemical control is achieved with homochiral cages. The photoreactions proceed under both aerobic and anaerobic conditions but through distinct pathways that nevertheless involve the same radical intermediates. This unusual dimerization constitutes a very rare example of asymmetric induction in biaryl coupling by making use of coordination cages with dual functionality-photoredox reactivity and stereoselectivity. [ABSTRACT FROM AUTHOR]

The combination of a transition-metal catalyst and organocatalyst was designed to achieve a highly enantioselective system for the allylic dearomatization reaction of naphthols with racemic secondary allylic alcohols. The desired β-naphthalenones, bearing an all-carbon quaternary center, were obtained in good yields with high chemo- and enantioselectivities. The cooperative catalytic system, involving a chiral iridium complex and phosphoric acid, provided measurable improvements in yields, and chemo- and enantioselectivities relative to single-catalyst systems. Control experiments indicated that the chiral iridium complex functions as a key species in the control of the absolute configuration, thus enabling the formation of both β-naphthalenone enantiomers by simply employing opposite enantiomeric ligands. [ABSTRACT FROM AUTHOR]

A new, simple and efficient method, including dispersive liquid-liquid-solidified floating organic drop microextraction and then electrothermal atomic absorption spectrometry, has been developed for the preconcentration and determination of ultratrace amounts of indium. The method was applied to preconcentrate the indium-1-(2-pyridylazo)-2-naphthol complex in 25 μL 1-undecanol. The various factors affecting the extraction efficiency, such as pH, type and volume of extraction solvent, type and volume of disperser solvent, sample volume, ionic strength, and ligand concentration, were investigated and optimized. Under the optimum conditions, an enrichment factor of 62.5, precision of ±4.75%, a detection limit of 55.6 ng L, and for the calibration graph a linear range of 96.0-3360 ng L were obtained. The method was used for the extraction and determination of indium in water and standard samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Two new small molecules, composed of naphthodithiophene (NDT) donor core and thienopyrroledione (TPD) group acceptor group end-capped with and without an alkyl-bithiophene, defined as NDT(TPD) 2 and NDT(TPDTT) 2 were designed and synthesized by stille coupling reactions. The thermal and electrochemical analyses carried out for both the small molecules revealed good thermal stability along with high decomposition temperature (>350 °C). NDT(TPD) 2 showed a deep HOMO level (−5.38 eV), compared to slightly upshifted HOMO (−5.26 eV) of NDT(TPDTT) 2 . While X-ray diffractometry suggests crystalline and amorphous nature of NDT(TPD) 2 and NDT(TPDTT) 2 respectively, the space charge limited current analysis revealed high hole mobility in the former and appreciable charge balance in the later. The conventional organic solar cell (OSC) devices fabricated using NDT(TPD) 2 and NDT(TPDTT) 2 as donor show power conversion efficiency (PCE) of 0.26% and 0.8% respectively. While NDT(TPDTT) 2 device after blending with additive, owing to the improved D-A heterojunction yielded maximum PCE of 1.31% resulting from enhanced J sc 3.32 mA/cm 2 , V oc 0.75 V and FF of 52.44. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a novel tetra-substituted phthalonitrile together with hexadeca-substituted metal-free and metallo phthalocyanines bearing naphthoxy groups in peripheral positions and hexyloxy groups in non-peripheral positions were described. Aggregation properties of phthalocyanine compounds were investigated in a concentration range of 1.4 × 10 −5 M to 4 × 10 −6 M. The energy transfer to phthalocyanine core and radiative decays of the naphthoxy emission and phthalocyanine core were examined. Electrochemistry of the complexes was studied with cyclic voltammetry and square wave voltammetry techniques. While zinc phthalocyanine (ZnPc) showed two phthalocyanine-based oxidation and two phthalocyanine-based reduction processes, cobalt phthalocyanine (CoPc) illustrated a metal-based and a phthalocyanine-based reductions and one metal-based and two phthalocyanine-based oxidation processes. Redox reactions of CoPcs are electrochemically and chemically reversible, while the reduction processes of ZnPc are reversible and the oxidation processes of ZnPc are quasi-reversible processes. [ABSTRACT FROM AUTHOR]

One-pot, efficient three-component condensation of aromatic aldehydes, 2-naphthol and 2-aminobenzothiazole in the presence of oxalic acid as an organocatalyst and effective catalyst for the synthesis of 1-(benzothiazolylamino) methyl-2-naphthol derivatives under thermal and solvent-free conditions is described. The present approach of this methodology offers several advantages such as high yields, clean reaction profiles, operational simplicity, being environmentally benign, lack of need for column chromatography and simple work-up procedure. Graphical Abstract: [ABSTRACT FROM AUTHOR]

An efficient and green one-pot method has been developed for the synthesis of amidoalkyl naphthol derivatives using reusable {[1,4-DHPyrazine](OTf)2} as an ionic liquid catalyst via condensation of aromatic aldehydes, β-naphthol and various amides under solvent-free conditions. [ABSTRACT FROM AUTHOR]

Tetrahydro-1,4-epoxynaphthalene-1-carboxylic acid (THENA), was applied as a chiral derivatizing agent to resolve 7,7′-disubstituted 1,1′-bi-2-naphthol derivatives. This process is very efficient and could potentially be used as a preliminary tool to assign the absolute configuration of substituted 1,1′-bi-2-naphthols by means of a simple TLC. [ABSTRACT FROM AUTHOR]

Two BINOL-based trifluoromethyl aryl ketones 3 and 4 show greatly enhanced fluorescence at 375 nm accompanied by a decrease at 500 nm when treated with aliphatic 1,2-diamines, especially ethylenediamine, in organic solvents. Under the same conditions, other monoamines and diamines caused much smaller or no fluorescence response. Thus, both 3 and 4 can be used as highly selective ratiometric fluorescence sensors for ethylenediamine. Compound 3, the BINOL hydroxyl groups of which are protected, exhibits greater fluorescence enhancement than the corresponding unprotected compound 4. UV and NMR spectroscopic studies have been conducted to probe the mechanism of the sensor-substrate reaction. [ABSTRACT FROM AUTHOR]

A series of 3 H-benzo[ f]chromen-3-ones containing the (2-hydroxy-1-naphthyl)methyl or 2-hydroxybenzyl substituent in position 2 was prepared by the reaction of 2-trifluoroacetyl-1 H-benzo[ f]chromenes with 2-naphthols in the presence of DBU. The reaction comprises 1,4-addition and intramolecular haloform type reaction followed by opening of the dihydropyran ring. [ABSTRACT FROM AUTHOR]