Naphthalene Moiety Research Articles

Naphtho[2,3- b]carbaporphyrins.

Acid-catalyzed condensation of a benzo[ f]indane dialdehyde with a tripyrrane, followed by an oxidation step, afforded the first example of a naphtho[2,3- b]-21-carbaporphyrin. This π-extended porphyrinoid system is strongly aromatic and gave a porphyrin-like UV-vis spectrum with a Soret band at 432 nm. Protonation with TFA gave a monocation, but under highly acidic conditions a C-protonated dication was generated. Reaction of the naphthoporphyrin with ferric chloride produced a 21-chloro derivative. Alkylation with methyl iodide and potassium carbonate gave a 22-methyl derivative, and this reacted with palladium(II) acetate to afford a palladium(II) complex in which the internal methyl group had migrated from a nitrogen to a carbon atom. Treatment of the naphthocarbaporphyrin with silver(I) acetate generated the corresponding silver(III) complex. In naphtho[2,3- b]-21-carbaporphyrin and many of its derivatives, the aromatic conjugation pathways appear to bypass the naphthalene unit, and for this reason the UV-vis spectra were little affected. However, the diprotonated dication and the palladium(II) complex have aromatic pathways that pass through the naphthalene moiety, and this leads to large bathochromic shifts for these species. The results provide insights on the influence of fused aromatic units on the reactivity, spectroscopic properties, and aromatic characteristics of carbaporphyrinoid systems.

C–H Monoarylation of Naphthylpyrimidines with Aryl Chlorides Catalyzed by a Water-Soluble Ruthenium Complex

Selective monoarylation of naphthylpyrimidines with a variety of aryl chlorides through C–H bond activation in water was achieved by using a water-soluble [RuCl2-(η6-PhOCH2CH2OH)]2/phosphine catalytic system. The monoarylation occurred at the C-2 carbon of the naphthalene moiety, and selectively polysubstituted naphthylpyrimidines were obtained by a one-pot reaction involving a subsequent hetarylation with 2-pyridyl chlorides.

Design, Synthesis, and Characterization of Binaphthalene Precursors as Photoactivated DNA Interstrand Cross-Linkers

Most recently, alkylation via photogenerated carbocations has been identified as a novel mechanism for photoinduced DNA interstrand cross-link (ICL) formation by bifunctional aryl compounds. However, most compounds showed a low efficiency for DNA cross-linking. Here, we have developed a series of new 1,1'-binaphthalene analogues that efficiently form DNA ICLs upon 350 nm irradiation via generated 2-naphthalenylmethyl cations. The DNA cross-linking efficiency depends on the substituents at position 4 of the naphthalene moiety as well as the leaving groups. Compounds with NO2, Ph, H, Br, or OMe substituents led to 2-4 times higher DNA ICL yields than those with a boronate ester group. Compounds with trimethylammonium salt as a leaving group showed slightly better cross-linking efficiency than those with bromo as a leaving group. Some of these compounds showed a better cross-linking efficiency than that of traditional alkylating agents, such as nitrogen mustard analogues or quinone methide precursors. These highly efficient photoactivated carbocation precursors allow determination and characterization of the adducts formed between the photogenerated naphthalenyl cations and four natural nucleosides, indicating that the alkylation sites for these naphthalene analogues are dG, dA, and dC.

Investigation of photophysical properties of 1,8-naphthalimides with an extended conjugation on naphthalene moiety via Suzuki coupling reaction

Five 4-substituted 1,8-naphthalimides (1-5), with an extended conjugation on the naphthalene ring, have been synthesized via Suzuki coupling reaction. These derivatives showed a large Stokes shift (up to 200 nm) and longer emission due to the increase of conjugation. Besides strong solvation effect, the low quantum yield were observed in protic solvents compared to in aprotic solvents. The anion forms of 1-5 obtained from reacting with NaH gave a significant red-shift for both absorption and emission spectra. These results provided a new strategy for preparation of fluorescent dyes with a long emission on the basis of 1,8-naphthalimde structure by using Suzuki coupling reaction.

Computational Structure Prediction of (4,4)-Connected Copper Paddle-wheel-based MOFs: Influence of Ligand Functionalization on the Topological Preference

The effect of linkers with extended π-system on the topological preference of (4,4)-connected copper paddle-wheel-based metal–organic frameworks (MOFs) was investigated using the reverse topological approach (RTA) in which a genetic algorithm (GA) and the DFT-derived force field MOF-FF were used for ranking and predicting the most stable phase. Three tetracarboxylate linkers bearing different functionality, namely, phenylene (L1), naphthalene (L2), and anthracene (L3) groups, were studied. All potential topologies including nbo-b, ssa, ssb, pts, and lvt-b were considered. The computational results reveal that nbo-b is the most stable topology for all three investigated linkers. However, L2 is also formed in ssb according to experimental findings. Our simulation results show that the CH−π interactions with a Y-shaped configuration between naphthalene moieties of L2 stabilize the ssb framework. Unlike L2, CH−π interactions are not favorable for L1 and L3 because of unsuitable size of the π-system. The resul...

Mbandakamine-Type Naphthylisoquinoline Dimers and Related Alkaloids from the Central African Liana Ancistrocladus ealaensis with Antiparasitic and Antileukemic Activities.

Four new dimeric naphthylisoquinoline alkaloids, michellamine A5 (2) and mbandakamines C-E (4-6), were isolated from the Congolese plant Ancistrocladus ealaensis, along with the known dimer mbandakamine A (3). They represent constitutionally unsymmetric dimers, each consisting of two 5,8'-coupled naphthylisoquinoline monomers. While the molecular halves of michellamine A5 (2) are linked via C-6' of both of the naphthalene moieties, i.e., via the least-hindered positions, so that the central biaryl axis is configurationally unstable and not an additional element of chirality, the mbandakamines 3-6 possess three consecutive stereogenic axes. Their monomeric units are linked through an unprecedented 6',1″-coupling in the binaphthalene core, leading to a high steric load, since the central axis is located in one of the peri-positions, neighboring one of the outer axes. In addition, four new 5,8'-coupled monomeric naphthylisoquinolines, viz., ancistroealaines C-F (7-10), were identified, along with four "naphthalene-devoid" tetra- and dihydroisoquinolines, named ealaines A-D (11-14). The new mbandakamines C (4) and D (5) showed pronounced activities against the malaria parasite Plasmodium falciparum, and they were likewise found to display strong cytotoxic activities against human leukemia (CCRF-CEM) and multi-drug-resistant tumor cells (CEM/ADR5000).

Synthesis and evaluation of the antibacterial activities of aryl substituted dihydrotriazine derivatives

Five series of dihydrotriazine derivatives containing chalcone (13a–i), phenoxy acetophenone (14a–b), benzyl benzene (15a–c), naphthoxyl acetophenone (16a–b) and benzyl naphthalene (17a–h) moieties were designed and synthesized. The antibacterial and antifungal activities of these compounds were evaluated against several strains of Gram-positive and Gram-negative bacteria, as well as a single fungus. Compound 17h was found to be the most potent of all of the compounds tested, with an MIC value of 0.5 μg/mL against several Gram-positive (Staphylococcus aureus 4220 and QRSA CCARM 3505) and Gram-negative (Escherichia coli 1924) strains of bacteria. However, this compound was inactive against Pseudomonas aeruginosa 2742 and Salmonella typhimurium 2421, indicating that its antibacterial spectrum is similar to those of the positive controls gatifloxacin and moxifloxacin. The cytotoxic activity of the compound 13i, 16b and 17h was assessed in Human normal liver cells.

Highly Selective Detection of Cr3 + Ion with Colorimetric & Fluorescent Response Via Chemodosimetric Approach in Aqueous Medium

So far, very few numbers of chemosensors for Cr3+ ion have been reported. However, the main drawback of reported receptors are the lack of selectivity and other trivalent cations such as Fe3+, Al3+ and anions like F- and -OAc frequently interfere with such assays. This paper present the synthesis, characterization & sensor studies of Schiff base containing naphthalene moiety which selectively detect Cr3+ ion by chemodosimetric approach. Using FT-IR, 1H NMR, 13C NMR and ESI mass spectroscopic techniques the probe was characterized. This receptor exhibit more selectivity and sensitivity towards Cr3+ than other divalent and trivalent cations like Mn2+, Zn2+, Co2+, Ni2+, Cd2+, Cu2+, Hg2+, Fe3+, and Al3+ ions. After the addition of chromium ion the receptor get change from yellow to colorless in aqueous medium. But no color change was observed on the addition of other metal ions. Using UV-Vis and PL studies, it was confirmed that the selective hydrolysis of imine group of receptor by Cr3+ ions takes place with high fluorescence enhancement that is corresponding to 1-naphthylamine. Receptor acts as selective chemodosimeter for Cr3+ ions with 2:1 stoichiometry and micro molar detection limit. This chemodosimetric approach was applied successfully for bio-imaging of HeLa cells.

Topochemical polymerization of macrocyclic diacetylene with a naphthalene moiety for a tubular-shaped polydiacetylene chromophore

Tubular-shaped chromophores have great potential in chemical and material sciences. A naphthalene-containing macrocyclic diacetylene (MCDA-Naph) was synthesized to access covalently linked organic nanotubes (ONTs) through topochemical polymerization. Single crystal X-ray analysis revealed that MCDA-Naph adopts the desired tubular array with favorable molecular orientation. UV irradiation of the molecularly stacked MCDA-Naph resulted in 1,4-addition polymerization and the generation of conjugated ene-yne chromophores. Density functional theory (DFT) provided evidence for tubular polydiacetylene nanotubes.

6-Methyl-1-(nitromethyl)-4-(propan-2-yl)naphthalene

The title compound, C15H17NO2, was synthesized in two steps from a mixture of α-himachalene (2-methylene-6,6,9-trimethylbicyclo[5.4.01,7]undec-8-ene), β-himachalene (2,6,6,9-tetramethylbicyclo[5.4.01,7]undeca-1,8-diene) and γ-himachalene (2,6,6,9-tetramethylbicyclo[5.4.01,7]undeca-2,8-diene), which was isolated from an essential oil of the Atlas cedar (Cedrus atlantica). The nitro group and the isopropyl group lie almost normal to the mean plane of the naphthalene moiety, making dihedral angles of 83.13 (19) and 71.72 (16)°, respectively, and are inclined to one another by 49.8 (2)°. In the crystal, molecules are linked by pairs of C—H...π interactions and weak C—H...O interactions.

A comparative study on inclusion complexation of substituted anilinonaphthalene sulfonic acids with 1,6,20,25-tetraaza[6.1.6.1]-paracyclophane and β-cyclodextrin

The inclusion complexations of paracyclophane (CP44) and β-cyclodextrin (β-CD) with several anilinonaphthalene sulfonic acids (ANSs) have been characterized via the enhancement of fluorescence spectra upon inclusion. β-CD and CP44 formed 1:1 inclusion complexes with ANSs, and the high stability of inclusion complexes of the latter was demonstrated. The thermodynamic parameters observed from the temperature dependence of the inclusion constants (van’t Hoff analysis) showed that CP44 inclusion complexations with ANSs are enthalpy-driven. Furthermore, the structure of the inclusion complexes was discussed based on 1H- and 2D ROESY-NMR measurements. It was found that CP44 encapsulates the naphthalene moiety of ANSs. On the other hand, differences in the structures of the β-CD inclusion complexes were observed for the 4-OH-substituted ANS. The molecular recognition for the inclusion of β-CD was found to be sensitive compared with that of CP44. In addition, the local polarity inside the CP44 and β-CD cavities was evaluated using ANSs as the fluorescence probe. Based on these results, we have suggested that the local polarity of ANSs in the hydrophobic cavities of CP44 and β-CD plays an important role in quantum yield enhancement upon inclusion.

Enhanced Proton Conductivity of Sulfonated Hybrid Poly(arylene ether ketone) Membranes by Incorporating an Amino-Sulfo Bifunctionalized Metal-Organic Framework for Direct Methanol Fuel Cells.

Novel side-chain-type sulfonated poly(arylene ether ketone) (SNF-PAEK) containing naphthalene and fluorine moieties on the main chain was prepared in this work, and a new amino-sulfo-bifunctionalized metal-organic framework (MNS, short for MIL-101-NH2-SO3H) was synthesized via a hydrothermal technology and postmodification. Then, MNS was incorporated into a SNF-PAEK matrix as an inorganic nanofiller to prepare a series of organic-inorganic hybrid membranes (MNS@SNF-PAEK-XX). The mechanical property, methanol resistance, electrochemistry, and other properties of MNS@SNF-PAEK-XX hybrid membranes were characterized in detail. We found that the mechanical strength and methanol resistances of these hybrid membranes were improved by the formation of an ionic cross-linking structure between -NH2 of MNS and -SO3H on the side chain of SNF-PAEK. Particularly, the proton conductivity of these hybrid membranes increased obviously after the addition of MNS. MNS@SNF-PAEK-3% exhibited the proton conductivity of 0.192 S·cm-1, which was much higher than those of the pristine membrane (0.145 S·cm-1) and recast Nafion (0.134 S·cm-1) at 80 °C. This result indicated that bifunctionalized MNS rearranged the microstructure of hybrid membranes, which could accelerate the transfer of protons. The hybrid membrane (MNS@SNF-PAEK-3%) showed a better direct methanol fuel cell performance with a higher peak power density of 125.7 mW/cm2 at 80 °C and a higher open-circuit voltage (0.839 V) than the pristine membrane.

Synthesis and Structure of a Longitudinally Twisted Hexacene.

The addition of phenyllithium to a polycyclic quinone, 9,11,12,21,22,24-hexaphenyltetrabenzo[a,c,n,p]hexacene-10,23-dione (10), followed by SnCl2 -mediated reduction of the diol intermediate, yielded 9,10,11,12,21,22,23,24-octaphenyltetrabenzo-[a,c,n,p]hexacene (4). Crystallographic analysis of hexacene 4 showed it to possess a longitudinal twist of 184°, which was in good agreement with AM1 calculations. In addition to being the most twisted acene synthesized to this point, compound 4 contains within its substructure the most twisted naphthalene, anthracene, tetracene, and pentacene moieties described.

The lead optimization of the polyamine conjugate of flavonoid with a naphthalene motif: Synthesis and biological evaluation

Polyamine conjugated flavonoid with a naphthalene moiety (ZYY14) displayed excellent therapeutic activity against hepatocellular carcinoma. In this study, three different series of novel flavonoid-polyamine conjugates were designed and screened against tumor cell lines. The structure-activity relationship study demonstrated the importance of the naphthalene moiety (as the B-ring), the basic side chains in the A-ring, and the methoxy group linked to the C-ring. The optimized compound 9b displayed better antitumor potency in vitro and in vivo than the lead compound ZYY14. Fluorescent assays revealed that 9b could enter cancer cells via polyamine transporter (PAT) and locate in mitochondria and endoplasmic reticulum. Compound 9b and ZYY14 demonstrated similar apoptotic mechanism in the cytotoxicity studies and stimulated the expression of apoptosis-related proteins, such as p-p38, p-JNK, p53 and Bax. In addition, 9b can initiate autophagy which inhibited the occurrence of apoptosis. Thus, 9b can be used as a valuable lead for the future development of antitumor agents.

Crystal and electronic structure of a hexacarbonyldiiron cluster tethered to naphthalene-2-thiolate ligands.

The structure of the previously reported complex bis(μ-naphthalene-2-thiolato-κ2S:S)bis(tricarbonyliron)(Fe-Fe), [Fe2(C10H7S)2(CO)6], has been characterized by X-ray diffraction. In the solid state, the dinuclear complex adopts a butterfly-like shape, with an equatorial-axial spatial orientation of the naphthalene groups covalently coupled to the [S2Fe2(CO)6] unit. The asymmetric unit contains three independent [(μ-naphthalene-2-thiolato)2Fe2(CO)6] molecules. These molecules show intermolecular π-π stacking interactions between the naphthalene rings, which was confirmed by Hirshfield surface analysis. The electronic spectrum of the complex recorded in acetonitrile shows a band centered at 350 nm (ℇ = 4.6 × 103 M-1 cm-1) and tailing into the visible region. This absorption can be attributed to a π→π* electronic transition within the naphthalene moiety and a metal-based d→d transition.

A Dipleiadiene‐Embedded Aromatic Saddle Consisting of 86 Carbon Atoms

AbstractThis study presents a new type of negatively curved nanographene (C86H32) that contains an unprecedented pattern of heptagons. A tert‐butylated derivative of C86H32 was successfully synthesized using tetrabenzodipleiadiene as a key building block. This synthesis involved a ring expansion reaction as a key step to form the seven‐membered rings in the framework of tetrabenzodipleiadiene. The single‐crystal structure reveals a saddle‐shaped molecule with a highly bent naphthalene moiety at the center of the polycyclic backbone. As found from the DFT calculations, this aromatic saddle is flexible at room temperature and has a saddle‐shaped geometry as the dominant conformation. The DFT calculations along with experimental results show that the attachment of t‐butyl groups to the central tetrabenzodipleiadiene moiety of nanographene C86H32 can stabilize the saddle conformation and make this nanographene less flexible.

A Dipleiadiene-Embedded Aromatic Saddle Consisting of 86 Carbon Atoms.

This study presents a new type of negatively curved nanographene (C86 H32 ) that contains an unprecedented pattern of heptagons. A tert-butylated derivative of C86 H32 was successfully synthesized using tetrabenzodipleiadiene as a key building block. This synthesis involved a ring expansion reaction as a key step to form the seven-membered rings in the framework of tetrabenzodipleiadiene. The single-crystal structure reveals a saddle-shaped molecule with a highly bent naphthalene moiety at the center of the polycyclic backbone. As found from the DFT calculations, this aromatic saddle is flexible at room temperature and has a saddle-shaped geometry as the dominant conformation. The DFT calculations along with experimental results show that the attachment of t-butyl groups to the central tetrabenzodipleiadiene moiety of nanographene C86 H32 can stabilize the saddle conformation and make this nanographene less flexible.

Synthesis and properties of [7]helicene and [7]helicene-like compounds with a cyclopenta[1,2-b:4,3-b']dithiophene or dithieno[2,3-b:3',2'-d]heterole skeleton.

A series of [7]helicene and [7]helicene-like compounds composed of a cyclopenta[1,2-b:4,3-b']dithiophene or dithieno[2,3-b:3',2'-d]heterole moiety and two naphthalene moieties were successfully synthesized from a common synthetic intermediate, 1,1'-binaphtho[2,1-b]thiophene. Their helical structures were confirmed by X-ray crystallographic analysis. The photophysical properties of them and their benzene analogues were investigated via absorption and fluorescence spectroscopy and theoretical calculations to correlate the effect of the five-membered rings in their π-conjugated skeleton. Through these investigations, the photophysical properties were found to largely depend on a combination of the central five-membered ring and the neighboring two aromatic rings. In particular, a combination of the central five-membered ring with electron-withdrawing character and the two neighboring thiophene rings was revealed to induce red-shifted emission.

Synthesis, biological evaluation and molecular docking studies of a new series of chalcones containing naphthalene moiety as anticancer agents

A series of chalcones containing naphthalene moiety 4a–4p have been synthesized, characterized by 1H NMR and 13C NMR and evaluated for their in vitro anticancer activity. The majority of the screened compounds displayed potent anticancer activity against both HCT116 and HepG2 human cancer cell lines. Among the series, compound 4h with a diethylamino group at the para position of the phenyl ring exhibited the most potent anticancer activity against HCT116 and HepG2 cell lines with IC50 values of 1.20 ± 0.07 and 1.02 ± 0.04 μM, respectively. The preliminary structure–activity relationship has been summarized. Tubulin polymerization experiments indicated that 4h effectively inhibited tubulin polymerization and flow cytometric assay revealed that 4h arrests HepG2 cells at the G2/M phase in a dose-dependent manner. Furthermore, molecular docking studies suggested that 4h binds to the colchicine binding site of tubulin.

High Proton Conductive Sulfonated Graph Copolyimide Membranes Containing Chemically Stable Naphthalene Moieties

Syntheses, proton conductivity, gas permeability properties, and membrane stabilities of novel sulfonated graft copolyimides were investigated. The sulfonated graft copolyimide membrane showed significantly high proton conductivity (0.96 S/cm at 90°C and 98%RH, more than 6 times that of Nafion), suggesting that the protons in the sulfonated graft copolyimide membranes were efficiently transported. The oxidative stability of the novel sulfonated graft copolyimide was higher than that of the conventional graft copolyimide because of their polymer structures containing chemically stable naphthalene moieties and non–sulfonated polymer main–chain. Furthermore, the oxygen permeability of the membrane was approximately one–fourth the value of Nafion and had a very excellent gas barrier property. We demonstrated that the graft copolymer membrane could realize high proton conductivity and low gas permeability to have potential applications for use in fuel cells.