Benzanthrone Derivatives Research Articles

Exploring the Chemistry, Reactions, Applications, and Biomedical Potentials of 2-Nitrobenzaldehyde and 2-Chlorobenzaldehyde

This article investigates the diverse chemical reactions and applications of 2-nitrobenzaldehyde, exploring its versatility in synthetic organic chemistry. The focus is on key reactions such as reduction to yield 2-aminobenzaldehyde, Schiff base synthesis with primary amines, Michael addition reactions, Sandmeyer reaction for the formation of 2-nitrobenzoic acid, selenium dioxide oxidation to 2-nitrobenzoic acid, and condensation reactions leading to benzanthrone derivatives. Each reaction pathway is discussed along with its potential applications in various fields. The second part of the review shifts the spotlight to 2-chlorobenzaldehyde, emphasizing its physical and chemical properties. Further exploration of 2-chlorobenzaldehyde's chemical reactivity reveals its engagement in nucleophilic addition reactions, alcoholysis reactions, acetylation reactions, reductive amination reactions, Witting reactions, and halogenation reactions. These reactions showcase the compound's adaptability and utility in diverse synthetic pathways. This article also discusses the biomedical application of 2-chlorobenzaldehyde and 2-nitrobezaldehyde.

Synthesis and Properties of New 3-Heterylamino-Substituted 9-Nitrobenzanthrone Derivatives

In the present study, new fluorophores based on disubstituted benzanthrone derivatives were designed starting from 9-nitro-3-bromobenzanthrone with nucleophilic substitution of the bromine atom with some secondary cyclic amines. It has been found that this reaction is positively affected by the presence of a nitro group in comparison with 3-bromobenzanthrone. The new compounds exhibit intense absorption and pronounced luminescent properties in various organic solvents. In this regard, their photophysical properties were evaluated with an experimental study of the solvatochromic behavior of the obtained compounds in various solvents. It has recently been found that the addition of an electron-withdrawing nitro group to the benzanthrone core increases its first- and second-order hyperpolarizability. Such dyes can be used in the fabrication of optical limiter devices. Therefore, the developed fluorescent molecules have a potential prospect for extensive application in optoelectronics.

3-[4-(2-Phenylethyl)piperazin-1-yl]-7H-benzo[de]anthracen-7-one

The present work describes the synthesis of the new benzanthrone dye-3-[4-(2-phenylethyl)piperazin-1-yl]-7H-benzo[de]anthracen-7-one by bromine atom nucleophilic substitution reaction. The structure of the obtained benzanthrone derivative is characterized by NMR spectroscopy, mass spectrometry, and X-ray diffraction analysis. The photophysical properties of the target compound are investigated by means of UV-Vis and fluorescence spectroscopy in various organic solvents.

3-(Phenylethynyl)-7H-benzo[de]anthracen-7-one

The present work describes the facile synthesis of 3-(phenylethynyl)-7H-benzo[de]anthracen-7-one via a Sonogashira coupling reaction. The structure of the synthesized benzanthrone derivative is characterized by 1H- and 13C-NMR spectroscopy and high-resolution mass spectrometry. The photophysical properties of the title compound are investigated by means of UV-Vis and fluorescence spectroscopy in various organic solvents.

Nonlinear optical properties of benzanthrone derivatives with N'-methylpiperazin-1-yl and N'-phenylpiperazin-1-yl substituents: Experimental and quantum chemical study

Benzanthrone derivatives namely 3-(4-methylpiperazin-1-yl)-7H-benzo[de]anthracen-7-one [Me-PBA] and 3-(4-phenylpiperazin-1-yl)-7H-benzo[de]anthracen-7-one [Ph-PBA] were exploited for their potential NLOphoric properties. We have unrevealed the relation between the chemical substitution and the nonlinear optical properties of the molecules. The third order NLO parameters of both the molecules in solution (0.01 M) were investigated using a continuous wave DPSS laser (532 nm) by Z-scan technique. The nonlinear absorption (NLA) profile of both the compounds was found to follow the two-photon absorption (TPA) model. Nonlinear absorption coefficient (β), nonlinear refractive index (n2) and second-order hyperpolarizability (γ) were found to be maximum for methyl substituted dye compared to phenyl substituted dye at 532 nm laser wavelength. The evaluated optical limiting values and figure of merit reveal that the samples are best suited for optical limiting and all-optical switching at 532 nm wavelength. In addition, we have carried out detailed theoretical studies and our calculations at the DFT level of theory are consistent with the experimental NLO results. Both the dyes exhibit a large Stokes shift of around ∼100 nm. And both of them exhibit a bathochromic shift of around ∼60 nm in polar solvents.

Amino acid functionalized benzanthrone dyes: Synthesis and photophysical study

The substitution reaction of 3-N-(2-chloroacetamido)benzanthrone with a number of the amino acids is reported. The possibility of using this halogenated benzanthrone for fluorescent labelling of amino acids has been studied. Arginine is the most reactive amino acid in the reaction, as it was found in the study. The spectral behavior of new benzanthrone derivatives depends on the polarity of the medium, exhibiting fluorescent solvatochromism due to intramolecular charge transfer from the substituted amino group to the carbonyl group. The results obtained indicate that the synthesized compounds are promising for studying peptides and proteins, as well as for visualizing biological objects.

Heterocyclic Schiff Bases of 3-Aminobenzanthrone and Their Reduced Analogues: Synthesis, Properties and Spectroscopy

New substituted azomethines of benzanthrone with heterocyclic substituents were synthesized by condensation reaction of 3-aminobenzo[de]anthracen-7-one with appropriate aromatic aldehydes. The resulting imines were reduced with sodium borohydride to the corresponding amines, the luminescence of which is more pronounced in comparison with the initial azomethines. The novel benzanthrone derivatives were characterized by NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The structure of three dyes was studied by the X-ray single crystal structure analysis. The solvent effect on photophysical behaviors of synthesized imines and amines was investigated. The obtained compounds absorb at 420–525 nm, have relatively large Stokes shifts (up to 150 nm in ethanol), and emit at 500–660 nm. The results testify that emission of the studied compounds is sensitive to the solvent polarity, exhibiting negative fluorosolvatochromism for the synthesized azomethines and positive fluorosolvatochromism for the obtained amines. The results obtained indicate that the synthesized compounds are promising as luminescent dyes.

Benzanthrone dyes as mediators of cascade energy transfer in insulin amyloid fibrils

Amyloid fibrils, a specific type of protein aggregates, involved in the development of a number of human disorders, currently attract a growing interest in biomedical and nanotechnological aspects. Recently, we demonstrated that amyloid assemblies may serve as a molecular framework for the multi-step Förster resonance energy transfer (msFRET) in the system containing the classical amyloid marker Thioflavin T (ThT) as the primary donor, the phosphonium mediator dye TDV, and the squaraine dye SQ1 as the terminal acceptor. In the present study we extended our efforts towards evaluating the possibility of using novel benzanthrone dyes as mediators of msFRET in the insulin amyloid fibrils. The four-chromophore systems: ThT → the 3-substituted benzanthrone derivative (BA) → the squaraine SQ4 → the squaraine SQ1 were designed to select the most effective mediators among a series of benzanthrones including the 3-methoxybenzanthrone (MBA) and its amino- (ABM, A6, A8) and amidino- (AM1, AM2) derivatives. The FRET efficiencies and the enhancement of SQ1 fluorescence in the fibrillar and non-aggregated insulin were compared to assess the suitability of the employed cascade system for amyloid fibril detection. The possible fibril binding sites for the examined dyes were defined based on the molecular docking studies. It is assumed that amyloid-scaffolded multichromophoric systems can be used in nanophotonic devices.

Palladium-Catalyzed Site-Selective Benzocyclization of Naphthoic Acids with Diaryliodonium Salts: Efficient Access to Benzanthrones

Dual activation of both C-I and vicinal C-H bonds of diaryliodonium salts allowing for diarylation is a subject of rapid construction of π-extended frameworks. Here, we report palladium-catalyzed cascade of C8-arylation/intramolecular Friedel-Crafts acylation of α-naphthoic acids in the synthesis of benzanthrone derivatives. The step-economical protocol tolerates various substrates, which resulted in a potential molecular library for developing functional polycyclic scaffolds. The approach relies on the synergistic action of strong acid with palladium catalysts to form two bonds in a one-pot procedure.

Palladium-Catalyzed C8-Arylation of Naphthalenes through C-H Activation: A Combined Experimental and Computational Study.

Herein, a direct C8-arylation reaction of 1-amidonaphthalenes is described. By using diaryliodonium salts as arylating agents, the palladium-catalyzed C-H activation reaction showed perfect C8 regioselectivity and a wide functional group tolerance. In most cases, the desired polyaromatic compounds were isolated in good to excellent yields. To explain the observed regioselectivity, DFT calculations were performed and highlighted the crucial role of the amide directing group. Finally, the utility of this method is showcased by the synthesis of benzanthrone derivatives.

Synthesis, spectral characteristics and microbiological activity of benzanthrone derivatives and their Cu(II) complexes

Two benzanthrone derivatives with an amide group (B1 and B2) attached to the C-3 atom have been synthesized and characterized by different spectral methods. The basic photophysical characteristics were investigated in organic solvents of different polarity. A batochromic shift was observed in the transition from non-polar to polar media. The influence of copper ions on the intensity of fluorescence emission was investigated and a stable copper complex with compound B2 was isolated. Its chemical structure was characterized by electronic spectroscopy, IR and EPR spectroscopy. The stoichiometry of the isolated complex was found to be at a 1: 1 ligand-copper ratio. The microbiological activity of the newly synthesized compounds against gram positive and gram negative bacteria and yeast was examined. The copper complex enhanced the antibacterial activity compared to that of the ligand.

Experimental and theoretical insights on the effect of solvent polarity on the photophysical properties of a benzanthrone dye.

Benzanthrone derivatives show interesting solvent dependent photophysical properties. Understanding of their photophysical properties is essential for developing the fluorescence probes based on benzanthrone derivatives. The photophysical properties of 3-(N'-chlorophenyl)piperazino-7H-benzo[de]anthracen-7-one [ClPh-PBA] molecule are reported in different solvents and solvent mixtures. The change in Stokes shift, quantum yield, fluorescence life time and radiative rate constants as a function of solvent polarity shows that the Intermolecular Charge Transfer (ICT) is affected by solvent polarity and hydrogen bonding. The quantum yield and fluorescence life time values decrease and the nonradiative decay rate constant (knr) values are observed to be higher in polar solvents. The weak emission of ClPh-PBA in polar solvents is primarily due to the non-radiative torsional motion of the chlorophenyl group around benzanthrone moiety. The torsional motion of chlorophenyl group at the remote nitrogen around benzanthrone moiety is also evident from TDDFT calculations performed using B3LYP/6-311+ G (d, p) basis set. The ground state and excited state dipole moments, absorption and emission maxima (nm) along with other quantum chemical parameters are obtained using B3LYP/6-311+ G (d, p) basis set. The experimental and theoretical results follow the similar trends.

Novel luminescent dyes for confocal laser scanning microscopy used in Trematoda parasite diagnostics.

Benzanthrone derivates are now widely used in many industrial and scientific applications as dyes for polymers and textiles. In biochemical, biomedical and diagnostics investigations benzanthrone dyes are used as a lipophilic fluorescent probe since many benzanthrone derivates demonstrate bright fluorescence and they have ability to intercalate between membrane lipids. The aim of research presented here was to assess the luminescence ability of benzanthrone derivatives using microscopic visualization of biological objects. Accordingly, specimens of freshwater trematodes: Diplostomum spathaceum, Diplodiscus subclavatus and Prosotocus confusus, were stained by novel benzanthrone dyes using different fixatives. The samples were examined under a confocal laser scanning microscope. All of the dyes tested demonstrated good results for digestive and reproductive system visualization. Based on obtained results we conclude that benzanthrone dyes could be used for internal and external structure confocal laser scanning microscopic imaging of trematode specimens.

Novel amidine derivatives of benzanthrone: Effect of bromine atom on the spectral parameters

Several new substituted amidine derivatives of benzanthrone were synthesized by condensation reaction from 2-bromo-3-aminobenzo[de]anthracen-7-one and appropriate aromatic or aliphatic amides. The novel benzanthrone derivatives were characterized by TLC analysis, NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The obtained derivatives have yellow or orange fluorescence in organic solvents. The solvent effect on photophysical behaviors of these dyes was investigated, and the results showed that the introduction of a bromine atom causes a blue-shift of the absorption and emission bands and decrease in the fluorescent quantum yield in comparison with unbromated analogues. The difference in the excited state and the ground state dipole moments was estimated by using the variation of Stokes shift and by semiempirical molecular calculations. The crystal structure and packing of four novel dyes has been revealed by the X-ray single crystal structure analysis.

Photophysical properties of benzanthrone derivatives: effect of substituent, solvent polarity and hydrogen bonding

Benzanthrone derivatives are potential fluorescent probes for various chemical and biological environments. A mechanistic understanding of their photophysical properties is pivotal for designing an efficient fluorescence sensor based on the benzanthrone framework. In this study, we report on the effect of chemical substitution on the photophysical properties of two benzanthrone derivatives, namely, 3-(N'-methyl)-piperazino-7H-benzo[de]anthracen-7-one [Me-PBA] and 3-(N'-phenyl)-piperazino-7H-benzo[de]anthracen-7-one [Ph-PBA] in different solvents and solvent mixtures of varying polarities and proticities. Both benzanthrone derivatives show interesting solvent-dependent photophysical properties. Although both derivatives exhibit strong intramolecular charge transfer (ICT) characteristics in the excited state, the extent of the charge transfer is significantly influenced by the nature of the chemical substitution. Modulation of photophysical parameters as a function of solvent properties led us to propose that ICT is affected by solvent polarity and hydrogen bonding. From the viscosity effect, it is revealed that the weaker emission of Ph-PBA compared to Me-PBA in polar solvents is primarily due to the non-radiative torsional motion of the phenyl group in the former derivative. In protic solvents, intermolecular hydrogen bonding imparts strong non-radiative deactivation to both derivatives, thus rendering a weak fluorescence yield.

Influence of Solvent Environment on Photophysical Properties of 3-(Piperidin-1-yl)-4H-benzo[de]anthracen-7(11bH)-one

The absorption and emission spectra of the benzanthrone derivative 3-(piperidin-1-yl)-4H-benzo[de]anthracen-7(11bH)-one [3-P4H-BDA] have been investigated in different solvents of varying polarities. The quantum yield (Φf) and lifetime (τ) values of this molecule were measured in various solvents. The radiative rate constant (Kr) and non-radiative rate constants (Knr) were also calculated. The nature of solute–solvent interactions was studied using Lippert plots and the Kamlet–Abboud–Taft polarity scale. Further, preferential solvation studies were carried out for the 3-P4H-BDA molecule in ethanol–DMSO and benzene–DMSO binary solvent mixtures. Ground state and excited state dipole moments of the 3-P4H-BDA molecule were calculated from the experimental results using the solvatochromic method and theoretically using the B3LYP/6-311 + G(d,p) method. Experimental values are in good agreement with the theoretical results. The HOMO–LUMO energy gap (eV), absorption and emission maxima in nm were calculated for the 3-P4H-BDA molecule using the B3LYP/6-311 + G(d,p) method. Also, ionization potential (I), electron affinity (A), electronegativity (χ), hardness (η) and softness (σ), global electrophilicity (ω) and chemical potential were calculated.

Newly synthesized benzanthrone derivatives as prospective fluorescent membrane probes

Fluorescence spectral properties of a series of novel benzanthrone derivatives have been explored in lipid bilayers composed of zwitterionic lipid phosphatidylcholine (PC) and its mixtures with cholesterol (Chol) and anionic phospholipid cardiolipin (CL). Analysis of partition coefficients showed that all the examined compounds possess rather high lipid-associating ability, with the amidino derivatives exhibiting stronger membrane partitioning compared with the aminobenzanthrones. To understand how benzanthrone partition properties correlate with their structure, quantitative structure property relationship (QSPR) analysis was performed involving a range of quantum chemical molecular descriptors.

Luminescence and structural properties of thermally evaporated benzanthrone dyes thin films

AbstractWe report optical and luminescence properties of 3-N, N-diacetylaminobenzanthrone thin films deposited on glass substrate by thermal evaporation. The structural and optical properties of organic thin films were studied by means of the confocal microscope with an input of femtosecond laser radiation, X-ray diffractometer, and scanning electron microscope (SEM). Intense luminescence with the maximum at 530 nm was observed when excited by laser radiation with the wavelengths 458, 476, 488, 496, 514 nm. In addition, the luminescence caused by two-photon absorption of femtosecond (fs) laser radiation has been investigated. Semi empirical calculations by AM1 and ZINDO/S methods and ab initio calculations using Gaussian software were carried out to estimate the electron system of structure. The calculations show planar configurations for the aromatic core and diacetylamino fragment of this compound. The study of the structure of benzanthrone derivative thin films with X-ray diffraction (XRD) methods, indicates the distance between molecular layers and ordered molecular fragments.

Fluorescent substituted amidines of benzanthrone: Synthesis, spectroscopy and quantum chemical calculations

Several new substituted amidine derivatives of benzanthrone were synthesized by a condensation reaction from 3-aminobenzo[de]anthracen-7-one and appropriate aromatic and aliphatic amides. The obtained derivatives have a bright yellow or orange fluorescence in organic solvents and in solid state. The novel benzanthrone derivatives were characterized by TLC analysis, 1H NMR, IR, MS, UV/vis, and fluorescence spectroscopy. The solvent effect on photophysical behaviors of these dyes was investigated, and the results showed that the Stoke’s shift increased, whereas quantum yield decreased with the growth of the solvent polarity. The structure of some dyes was confirmed by the X-ray single crystal structure analysis. AM1, ZINDO/S and ab initio calculations using Gaussian software were carried out to estimate the electron system of structures. The calculations show planar configurations for the aromatic core of these compounds and two possible orientations of amidine substituents. The calculation results correlate well with red-shifted absorption and emission spectra of compounds.

3-N-2-hydroxyethylamine benzanthrone 및 3-N-2-aminoethylamine benzanthrone에 대한 Cu(II), Ni(II) 및 Co(II) 착물의 분광학, 열 및 생물학적 연구

본 연구에서는 Benzanthrone 치환체인 3-N-2-hydroxy ethylamine benzanthrone (HEAB)와 3-N-2-amino ethylamine benzanthrone (AEAB)의 Cu(II), Co(II) 및 Ni(II) 염화물 착물에 대한 분광학 (IR, UV-vis 및 <TEX>$^1H$</TEX>-NMR), 원소분석, 몰전도도, 열무게분석 (TGA/DTG) 및 생물학적 특성에 대해 고찰하였다. 이 연구의 결과에서 HEAB리간드가 히드록소 및 아미노기를 통하여 각 금속에 배위되어 [Cu(HEAB)<TEX>$(Cl)_2$</TEX>].<TEX>$2H_2O$</TEX>, [Co(HEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$8H_2O$</TEX> 및 [Ni(HEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$7H_2O$</TEX> 착물을 형성함을 알았다. 한편, AEAB는 [Cu(HEAB)<TEX>$(Cl)_2$</TEX>].<TEX>$2H_2O$</TEX>, [Co(HEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$8H_2O$</TEX> 및 [Ni(HEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$7H_2O$</TEX>의 분자식을 갖는 팔면체 배위구조를 갖는다. <TEX>$25^{\circ}C$</TEX> DMF에서 모든 착물의 몰전기전도도는 반응안한 리간드보다 약간 컸는데, 이는 염화 이온이 배위권 내부에 존재함을 의미한다. Benzanthrone계 리간드와 이들 착물을 이용하여 서로 다른 종류의 박테리아에 대한 생물활성을 조사하였다. Spectroscopic (infrared, electronic and <TEX>$1^H$</TEX>-NMR), elemental analyses CHN, molar conductivity, thermogravimetric analyses (TGA/DTG) and biological studies, of both benzanthrone derivatives 3-N-2-hydroxy ethylamine benzanthrone (HEAB) and 3-N-2-amino ethylamine benzanthrone (AEAB) with Cu(II), Co(II) and Ni(II) chlorides were discussed herein. Based on the above studies, HEAB ligand was suggested to be coordinated to each metal ions via hydroxo and amino groups to form [Cu(HEAB)<TEX>$(Cl)_2$</TEX>].<TEX>$2H_2O$</TEX>, [Co(HEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$8H_2O$</TEX> and [Ni(HEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$7H_2O$</TEX> coordinated complex. On the other hand, AEAB has an octahedral coordinated feature with formulas [Cu(AEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$2H_2O$</TEX>, [Co(AEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>].<TEX>$4H_2O$</TEX> and [Ni(AEAB)<TEX>$(Cl)_2(H_2O)_2$</TEX>]. <TEX>$6H_2O$</TEX>. The molar conductance values at <TEX>$25{\circ}C$</TEX> for all complexes in DMF are slightly higher than free ligands; this supported the presence of chloride ions inside the coordination sphere. Both benzanthrone ligands and their complexes have been screened against different kinds of bacteria.