Dibenzoylmethane Research Articles

Unveiling the Versatility of Coumarin-Integrated with Phenanthroline/Thiabendazole-Based EuIII Complexes for Smart LEDs, Vapoluminescence, and Bioimaging Applications.

Narrow band red-emitting phosphors based on organo-Eu(III) complexes prove their energetic features with surprising performance in smart red/white LEDs, sensing, and biological fields. In this report, a series of unique Eu(III) complexes have been synthesized with coumarin integrated with a class of phenanthroline(Phen)/thiabendazole(TBZ) based ancillary ligands and dibenzoyl methane (DBM)/2-theonyl trifluoroacetone (TTA) as an anionic ligand. The computational study reveals that the TBZ/Phen-based neutral ligands are superior energy harvesters to those other reported analogue neutral ligands. All the Eu-complexes demonstrated outstanding red emission due to electric dipole (ED) transition (5D0 → 7F2) in solid, solution, and thin film with high quantum yield (QY). Theoretical analysis (TD-DFT) and experimental findings describe that the energy transfer (ET) from the ligand's triplet level to the Eu(III) ion is completely occurring. The Eu(III) complexes can potentially be used to fabricate intense hybrid white and red LEDs. All of the fabricated red LEDs revealed high luminous efficiency of radiation (LER) values. The fabricated blue LED based hybrid white LEDs displayed remarkable performance with a low correlated color temperature (5634 K), high color rendering index 88%, and CIE values (x = 0.33; y = 0.342) for 3Eu. By interaction with acid-base vapors, Eu-complexes displayed effectively alterable on-off-on luminescence. Further, cellular imaging shows that Eu-complexes can be a potential biomarker for cancer cell lines.

Ternary Eu3+ crystalline complexes with photoluminescence and triboluminescence for dynamic stress visualization

Investigation of photoluminescence (PL) and fracture-induced triboluminescence (TL) is necessary for the development of both fundamental theories and practical applications in mechanical energy conversion; however, most known PL/TL-emitting materials are confined to inorganic systems. In this study, a novel lanthanide-based crystalline complex (LnCC), Eu(DBM)3DETA was synthesized via the synergistic coordination of Eu3+ with DBM (Dibenzoylmethane) and DETA (Diethylenetriamine) units, leading to the formation of brighter LnCC with bright red emission, high PL quantum yields (57.19 %) and unique TL characteristics. The key to success in obtaining Eu(DBM)3DETA is the utilization of DETA molecule as synergistic ligand, presenting block crystals with higher coordination number of Eu3+ ions via recrystallization. Due to the dense accumulation of cross-linked three-dimensional frameworks through van der Waals interactions, the fracture-induced piezoelectric effect results in charge separation and excitation through the resultant electric field and discharge, triggering a fast TL response of Eu(DBM)3DETA and expanding the possibilities of the quantitative stress sensing. Importantly, amorphous powders can still recover to their original PL and TL emission intensities after recrystallization in cyclic crystal-to-amorphous phase transitions. The unique PL and TL characteristics of Eu(DBM)3DETA provide promising opportunities to display stress visualization differences of electronic signatures under different forces.

References for Small Fluorescence Quantum Yields.

Three compounds with fluorescence quantum yields in the range of 10- 5 to 10- 4 and emission spectra covering the UV/Vis spectral range are suggested as new references for the determination of small fluorescence quantum yields. The compounds are thymidine (dT) in water, dibenzoylmethane (DBM) in ethanol, and malachite green chloride (MG) in water, representing the blue, green, and red regions of the spectrum, respectively. All compounds are easily handled, photostable, and commercially available. Furthermore, these compounds exhibit a mirror-image symmetry between their absorption and fluorescence spectra. This symmetry, along with closely aligned fluorescence excitation and absorption spectra, confirms that the observed emissions originate from the compounds themselves. The fluorescence quantum yields were determined via a relative approach as well as Strickler-Berg analysis in conjunction with time resolved fluorescence spectroscopy. Within the respective error margins, the two approaches yielded identical results.

Crystallization management and defect passivation via additive engineering for efficient and stable carbon-based CsPbI2Br perovskite solar cells

Inorganic CsPbI2Br perovskite solar cells (PSCs) have attracted enormous interest due to their excellent thermal stability and immense potential for application in tandem solar cells. However, the rambunctious crystallization and poor film quality of inorganic CsPbI2Br perovskite are the main factors limiting their performance improvement. Herein, dibenzoylmethane (DBM), containing electron-rich and dual CO functional groups, as an efficient precursor additive, is first introduced to regulate the crystallization of CsPbI2Br perovskite while passivating its associated defects. After DBM modification, nucleation is accelerated and the crystallinity of CsPbI2Br film is improved, thus promoting the phase stability. Additionally, DBM can passivate uncoordinated Pb2+ defects, thereby significantly reducing non-radiative recombination, and can also decrease the energy level difference between CsPbI2Br/Carbon. As a result, when DBM additive is incorporated in the CsPbI2Br, the power conversion efficiency (PCE) of the device with the fluorine doped tin oxide glass (FTO)/SnO2/CsPbI2Br/Carbon structure is significantly improved to 13.46 %, an increase of nearly 13 % compared to the control device (11.72 %). The unpackaged devices exhibit excellent air and thermal stability, still remaining over 90 % of its initial PCE after aging for 500 h under ambient conditions, or continuous heating at 65 °C in glovebox for 500 h, respectively.

Potential Alzheimer’s early biomarkers in a transgenic rat model and benefits of diazoxide/dibenzoylmethane co-treatment on spatial memory and AD-pathology

Alzheimer’s disease (AD) is the major form of dementia prevalent in older adults and with a high incidence in females. Identification of early biomarkers is essential for preventive intervention to delay its progression. Furthermore, due to its multifactorial nature, a multi-target approach could be therapeutically beneficial. Our studies included 4- (pre-pathology) and 11-month (mild-pathology) TgF344-AD rats, a transgenic Alzheimer’s model that exhibits age-dependent AD progression. We identified two potential early biomarker genes for AD, early growth response 2 (EGR2) and histone 1H2AA (HIST1H2AA), in the hippocampus of 4-month females. Out of 17,168 genes analyzed by RNA sequencing, expression of these two genes was significantly altered in 4-month TgF344-AD rats compared to wild-type littermates. We also evaluated co-treatment with diazoxide (DZ), a potassium channel activator, and dibenzoylmethane (DIB), which inhibits eIF2α-P activity, on TgF344-AD and wild-type rats. DZ/DIB-treatment mitigated spatial memory deficits and buildup of hippocampal Aβ plaques and tau PHF in 11-month TgF344-AD rats but had no effect on wild-type littermates. To our knowledge, this preclinical study is the first to report EGR2 and HIST1H2AA as potential AD biomarkers in females, and the benefits of DZ/DIB-treatment in AD. Evaluations across multiple AD-related models is warranted to corroborate our findings.

Effect of Sm(DBM)3Phen incorporation methodology on spectroscopic properties of PVA nanofibres

Electrospun nanofibres are an advancing area of research because of their flexible characteristics and numerous applications in sensors, optoelectronic devices, etc. Herein, we first prepared lanthanide complex Sm(DBM)3Phen. The synthesized complex was then incorporated into and onto the surface. The detailed study of spectroscopic properties of electrospun nanofibres into and onto the surface is presented. The fabricated nanofibres of Sm(DBM)3Phen into the nanofibres surface had a diameter of around 295 nm and length > 200 µm and the surface morphology of the complex incorporated nanofibres presented that the nanofibres were smooth and straight and were highly interlaced. The nanofibres with Sm complex on the surface presented a rough surface morphology. The spectroscopic analysis shows energy transfer from the ligand Dibenzoylmethane (DBM) to Sm3+ ion, enhancing its photoluminescence intensity. Under UV excitation, the Sm(DBM)3Phen incorporated nanofibres exhibited emission peaks between 550 nm and 710 nm and with sharp peaks at 564, 598 nm, and 646 nm, which are assigned to the transition from 4G5/2 to 6HJ (J = 5/2, 7/2, and 9/2) attributed to DBM. The photoluminescence intensity of the two nanofibres varied with the incorporation method. A detailed spectroscopic analysis of the synthesized samples with the incorporation methodology is carried out.

Trivalent Tetraazamacrocyclic Complexes of Cr(III) and Fe(III): Synthesis, Characterization and Antimicrobial Evaluation

A novel series of macrocyclic compounds, [M(C37H36N4)X]X2; where M = Cr(III) and Fe(III); X = Clˉ, NO3ˉ, CH3COOˉ, have been synthesized by using the template condensation between 3,4-diaminotoluene, dibenzoyl methane and dimedone in the presence of chromium(III) and iron(III). Various physio-chemical studies were used to characterize these complexes including PXRD, magnetic susceptibility, elemental analysis, electronic, IR and mass spectroscopy. These studies suggested that all the metal complexes have a five-coordinated square pyramidal geometry around the metal ion. The molar conductance values of these complexes in the range of 168-140 ohm-1cm2mol-1 indicated the electrolytic nature of these complexes. Furthermore, the antibacterial and antifungal behavior of these complexes was also examined by using different microbial strains i.e. Bacillus subtilis, Escherichia coli and Candida albicans. In addition to this, the results of antibacterial and antifungal of complexes were compared with commercially available antibacterial and antifungal drug i.e. ciprofloxacin and Amphotericin B, respectively.

Synthesis and Antibacterial Activity of Spiro[4H-pyran-3,3'-oxindoles] Catalyzed by Tröger's Base Derivative.

Two classes of spiro[4H-pyran-3,3'-oxindole] derivatives were prepared via the one pot reaction of chain diketones (1-phenyl-1,3-butanedione or dibenzoyl methane), substituted isatins and malononitrile successfully catalyzed by a Tröger's base derivative 1b (5,12-dimethyl-3,10-diphenyl-bis-1H-pyrazol[b,f][4,5]-1,5-diazadicyclo[3.3.1]-2,6-octadiene). The antibacterial activity of products against three wild-type bacteria (B. subtilis, S. aureus, and E. coli) and two resistant strains (Methicillin-resistant S. aureus (18H8) and E. coli carrying the BlaNDM-1 gene (18H5)) was evaluated using the minimum inhibitory concentration (MIC).. 1-Phenyl-1,3-butanedione 2 or dibenzoylmethane 2' (0.42 mmol), substituted isatin 3 (0.4 mmol), malononitrile 4 (0.8 mmol), Tröger's base derivative 1b (0.08 mmol), and 10 mL of acetonitrile were added to a 50 mL round bottom flask and refluxed. After the completion (TLC monitoring), water (10 mL) was added to the reaction mixture; pH = 7 was adjusted with saturated NaHCO3 (aq.), and the mixture was extracted with CH2Cl2 (50 mL × 3). Organic layers were combined and dried with anhydrous Na2SO4; the solvent was removed under vacuum, and the residue was purified by column chromatography (VDCM: VMeOH = 80: 1) to afford product 5. The antibacterial activity was tested by the MTT method. Seventeen spiro[4H-pyran-3,3'-oxindole] derivatives were synthesized through the reaction of chain diketones (1-phenyl-1,3-butanedione or dibenzoyl methane), substituted isatins, and malononitrile in one-pot in medium to high yields. Four compounds showed antibacterial activity, and two of them showed the same activity as the positive control Ceftazidime on S. aureus (MIC = 12.5 μg/mL). Two classes of spiro[4H-pyran-3,3'-oxindole] derivatives were prepared, and their antibacterial activity was evaluated. Tröger's base derivative 1b (5,12-dimethyl-3,10-diphenyl-bis-1H-pyrazol[b,f][4,5]- 1,5-diazadicyclo[3,3,1]-2,6-octadiene) was used as an efficient organocatalyst for the reaction of low reactive chain diketones (1-phenyl-1,3-butanedione or dibenzoyl methane), substituted isatins, and malononitrile in one-pot successfully and effectively by providing multiple active sites and alkaline environment. By the theoretical calculation, we explained the possible reaction sequence and mechanism. Due to the superiority and high efficiency of the TB framework as an organocatalyst, the reaction showed many advantages, including mild reaction conditions, low catalyst loading, and a wide substrate range. It expanded the application of Tröger's base to the multicomponent reaction in organocatalysis. Some products were screened due to their high antibacterial activity in vitro, showing their potential in new antibacterial drug development.

Investigating the long-term stability of photoluminescence lifetimes in PMMA films doped with β-diketonate europium complexes based on bipyridine and terpyridine derivatives

In this work, two β-diketonate ligands: dibenzoylmethane (DBM) and Hexafluoroacetone (hfac) have been selected to synthesize a series of β-diketonate europium complexes based on bipyridine and terpyridine derivatives. These complexes were then incorporated into PMMA films to comprehensively investigate their thermal and long-term photoluminescence stability. Comparatively, Eu(hfac)3L1-5 demonstrated higher heat resistance than Eu(DBM)3L1-5, as indicated by their respective initial decomposition temperatures. Various aspects including absorbance, excitation, and emission were examined in solution, powder, and within the PMMA-doped films. Notably, the complexes exhibited a remarkable red emission peak at 613nm and a high photoluminescence quantum yield. To assess their stability, the films were subjected to light, indoor, and dark storage conditions for 720h, with photoluminescence measurements recorded at both 0h and 720h. The results revealed that the hfac-based europium complexes (Eu(hfac)3L1-5) demonstrated good stability under light, indoor, and dark conditions compared to the DBM-based europium complexes (Eu(DBM)3L1-5). This study highlights the direct impact of the β-diketonate ligand structure on the stability of such complexes in films, thus showcasing their potential for future applications in stable optoelectronic devices.

Anti-carcinoma and anti -microbial behavioral studies for octahedral synthesized Schiff base metal complexes

2,2′-((1Z-1′Z) (1,3-diphenylpropane-1,3-diylidene) bis (azanylylidene)) dibenzoic acid (H2L) Schiff base ligand, derived from condensation reaction in a molar ratio 2:1 between anthranilic acid and dibenzoyl methane, respectively. Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes were obtained from 1:1 (ligand: metal salt) reaction. Elemental analyses, IR, 1H NMR, UV–Vis, ESR, mass spectra, conductivity, and magnetic susceptibility measurements as well as thermal (TG/DTG) analyses have been used to conclude the molecular structure of the prepared complexes. From the analytical and spectroscopic tools, the stoichiometry of the complexes was found to be of ML type with octahedral geometry. The conductivity values supported the electrolytic nature of Cr(III) and Fe(III) complexes and non- electrolytic nature of the remaining complexes. From IR studies, the involvement of two azomethine nitrogen atoms and two carboxylate oxygen has been proved as tetradendate binding sites of the ligand. Screening Schiff base and its complexes for their antimicrobial activity against Streptococcus pneumoniae and Bacillus subtilis as G + bacteria; Pseudomonas aeruginosa and Escherichia coli as G− bacteria) and fungi (Aspergillus fumigatus; Syncephalastrum racemosum; Geotricum candidum and Candida albicans) has been conducted by disk diffusion method. The Comparison between the antimicrobial activity of the metal complexes and the free ligand showed the advancement of the metal complexes. Unfortunately, no promising anti-tumor activity has been detected for the ligand and its metal complexes as they were evaluated against human cancer (MCF-7 cells viability).

Quantum chemical calculation assisted efficient lithium extraction from unconventional oil and gas field brine by β-diketone synergic system

The lithium extraction from emerging unconventional oil and gas (UOG) field brine by β-diketone synergic system was established and systematically studied for the first time. A synergistic system consisting of dibenzoylmethane (DBM) and trioctylphosphine oxide (TOPO) was screened for lithium extraction through high-precise DFT calculation, and the synergistic effects were revealed by FT-IR analysis. A state-of-the-art Li+-Mg2+-Ca2+ co-extraction and Li+ selective stripping (CESS) process was proposed to achieve high lithium recovery efficiency. The effects of saponification, phase ratio, extractant composition and stripping acidity on extraction efficiency were systemically studied using real UOG field brine. After three-stage countercurrent extraction, the lithium extraction efficiency reached 98.1 % with the DBM concentration of 0.25 mol/L, TOPO concentration of 0.25 mol/L, and saponification of 70 %. After selective stripping and scrubbing with gradient HCl concentrations, Li+ was further separated from Na+, Mg2+ and Ca2+. The mass ratio of Mg2+/Li+ was reduced by 49.7 times, Na+/Li+ was reduced by 102.4 times. This work bridged the gap in the solvent extraction of lithium resources from UOG field brines and provided ideas for UOG field resource exploit and comprehensive utilization.

Development of red-luminescent hybrids as contrast agents for cell imaging: A correlation among surface, luminescence, and biological properties

TTA (2-thenoyltrifluoroacetone), DBM (dibenzoylmethane), and EPHEN (5,6-Epoxy-5,6-dihydro- [1,10] phenanthroline) have generated europium complexes with excellent red emission properties. However, for bio applications, these complexes have been grafted on the surface of silica nanoparticles (SNP), by different approaches, due to their low water solubility. Here, we report how three approaches influence the surface, luminescent, and biological properties of 50 and 170 nm-SNP functionalized with carboxylic acid or phenanthroline ligands, useful to anchor TTA and DBM-Eu-complexes. TTA-hybrids exhibited better photophysical properties over the DBM ones, although intermolecular interactions between TTA and silica surface groups are likely to influence their properties. Aiming at such biological application, approach 3 resulted in the luminescent PHEN-hybrids with the highest values of intrinsic (φEuEu) and absolute quantum yields (φEuL), color purity of 100%, and high sensibilization efficiency (η). However, depending on the approach used, different surface charges were observed for the hybrids that directly impacted their cytotoxicity in Huh 7.5 cells. The larger the size of the nanoparticle or the more positive its surface charge is, the lower the toxicity of the hybrid. Even considering the presence of the protein corona effect, estimated in DMEM medium, the initial surface charge, observed in the buffer solution, plays an important role in the nanoparticle-cell interaction. Confocal microscopy images revealed that the hybrids were internalized by cells regardless of their size and surface charge, and their luminescence was also detectable, making them promising candidates for cell imaging applications as luminescent contrast agents.

Dibenzoylmethane ameliorates adiposity-mediated neuroinflammatory response and inflammation-mediated neuronal cell death in mouse microglia and neuronal cells.

Dibenzoylmethane (DBM), a licorice-derived component, has numerous health benefits. The current study aimed to investigate the effect of DBM on adiposity-induced neuroinflammatory/oxidative response and microglial activation-induced neuronal cell damage. For this research, BV2 and HT22 cells were cultured using adipcyte- and microglia-conditioned media, respectively. DBM effectively suppressed lipopolysaccharide-induced productions in inducible nitric oxide synthase and cyclooxygenase2. Interleukin (IL)-6, monocyte chemoattractant protein-1, IL-1β, and tumor necrosis factor-α levels were also downregulated by DBM. In adipocyte-conditioned medium (ACM)-cultured BV2 cells, DBM effectively decreased ACM-induced generation of nitric oxide, reactive oxygen species, and inflammatory cytokines by activating nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling and reducing nuclear factor kappa-light-chain-enhancer of activated B cells. In BV2-conditioned medium (BVM)-cultured neuron cells, DBM recovered the BVM-induced reduction of neuronal cell viability, thereby regulating B-cell lymphoma 2 (BCL2), BCL2-associated X (BAX), and cleaved caspase-3 protein expression. Taken together, DBM suppressed adiposity-induced inflammation/oxidative responses and inflammation-induced neuronal cell death.

Mechanisms of Ganweikang Tablets against Chronic Hepatitis B: A Comprehensive Study of Network Analysis, Molecular Docking, and Chemical Profiling.

The hepatitis B virus (HBV) is one of the major viral infection problems worldwide in public health. The exclusive proprietary Chinese medicine Ganweikang (GWK) tablet has been marketed for years in the treatment of chronic hepatitis B (CHB). However, the pharmacodynamic material basis and underlying mechanism of GWK are not completely clear. This study is aimed at investigating the pharmacological mechanism of the GWK tablet in the treatment of CHB. The chemical ingredient information was obtained from the Traditional Chinese Medicine Database and Analysis Platform (TCMSP), Traditional Chinese Medicines Integrated Database (TCMID), and Shanghai Institute of Organic Chemistry of CAS. Ingredients and disease-related targets were defined by a combination of differentially expressed genes from CHB transcriptome data and open-source databases. Target-pathway-target (TPT) network analysis, molecular docking, and chemical composition analysis were adopted to further verify the key targets and corresponding active ingredients of GWK. Eight herbs of GWK were correlated to 330 compounds with positive oral bioavailability, and 199 correlated targets were identified. The TPT network was constructed based on the 146 enriched targets by KEGG pathway analysis, significantly associated with 95 pathways. Twenty-five nonvolatile components and 25 volatile components in GWK were identified in UPLC-QTOF/MS and GC-MS chromatograms. The key active ingredients of GWK include ferulic acid, oleanolic acid, ursolic acid, tormentic acid, 11-deoxyglycyrrhetic acid, dibenzoyl methane, anisaldehyde, wogonin, protocatechuic acid, psoralen, caffeate, dimethylcaffeic acid, vanillin, β-amyrenyl acetate, formonentin, aristololactam IIIa, and 7-methoxy-2-methyl isoflavone, associated with targets CA2, NFKB1, RELA, AKT1, JUN, CA1, CA6, IKBKG, FOS, EP300, CREB1, STAT1, MMP9, CDK2, ABCB1, and ABCG2.

Preparation and performance of PVC long‐term heat stabilizer based on the synergistic effect of uracil and metal complexes

AbstractIn order to improve the deficiency of traditional polyvinyl chloride (PVC) heat stabilizer, triazole‐based zinc‐containing complex (abbreviated as [Zn(ttr)(OAc)]) with good compatibility with PVC and a strong ability to absorb HCl was prepared in this paper, which was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). PVC sheets were prepared by mixing PVC with composite heat stabilizer (DAJ) composed of [Zn(ttr)(OAc)] and 1,3‐dimethyl‐6‐aminouracil (DAU). Different kinds and amounts of common auxiliary heat stabilizers were selected and added to the DAJ system to study the effect of thermally stable system on PVC by Congo red test, Discoloration test, Dynamic thermal stability test, SEM, TGA and Transmittance test and the relevant mechanism was explored. The PVC sheets with DAJ blended by 1.2 phr DAU and 0.8 phr [Zn(ttr)(OAc)] showed relatively excellent coloring properties, long‐term thermal stability, and high light transmittance. Compared with dibenzoylmethane (DBM), 0.5 phr sorbitol and 1.5 phr epoxy soybean oil (ESBO)/Antioxidant 168 showed good synergistic effect with DAJ. Due to the polyhydroxy nature of sorbitol, the thermal stability of PVC was significantly improved, and the transmittance of PVC benefited from the similar miscibility of ESBO long chain. This was also confirmed by TGA and SEM of PVC sheet.

Synergism antibacterial activity for novel synthesized Schiff base ligands and semi-thiosemicarbazones with ß-diketones and 4-aminoantipyrine

Schiff base ligands were synthesised in this work, the first is (Z)-2-((Z)-3-((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)imino)-1,3-diphenylpropylidene) hydrazine-1-carboxamide, the second is (Z)-2-((1E,5Z,6E)-5-((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)imino)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-dien-3-ylidene)hydrazine-1-carbothioamide. The Schiff base ligands both were synthesised using the same method (the single pot reaction), using EtOH as the reaction medium and GAA as the catalyst in fixed temperature at 70 0C and reflux for 6 hrs. The starting materials of HL1 were semicarbazide,4-aminoantipyrine and dibenzoyl methane, while the starting materials of HL2 were TSC, 4-AAP and Curcumin. The ligands proved to be bi-dentate ligands that coordinate from the azomethane groups. FT-IR, U.V-Visible, 1H and 13C- NMR, molar conductivity, and magnetic susceptibility were used to identify all the compounds produced. The metal ions used in preparing the complexes in this work were Co(II), Cu(II) and Cr(III). Schiff base and its complexes were evaluated for antibacterial activity against four bacterial strains of Gram-negative (Escherichia coli and Pseudomonas aeruginosa), Gram-positive (Staphylococcus aureus and Bacillus Subtilis) and two types of fungi (Candida albicans and Rhizopus Sporium), the results were positive for all compounds tested. Keywords: Schiff base, Curcumin, 4-aminoantipyrine

Luminescent heteroleptic samarium (III) complexes: Synthesis, optical and photophysical investigation

• We have synthesized photoluminescent ternary samarium β-diketonate complexes with heterocyclic neutral ligands. • Optical and luminescent nature of red color emissive ternary samarium complexes have been studied in detail. • Photoluminescence emission spectra specify that β-diketone ligand efficiently sensitized Sm(III) ion via antenna effect. • Synthesized luminescent materials could found good significance in solid state electronics, flat panel devices and OLEDs. The octa coordinated complexes of Sm 3+ with dibenzoylmethane (DBM) having general formula [Sm(X) 3 (Y)] were synthesized in powdered form and characterized spectroscopically. Here, X is dibenzoylmethane (DBM) and Y represents respective substituted 2,2 ′ -bipyridine derivatives. The luminescent characteristics of ternary samarium complexes have been studied in detail. Upon excitation in UV range, bands at 566 nm, 606 nm, 648 nm (highly intense) and 710 nm were appeared in emission spectra of complexes attributed to characteristic transitions of Sm(III) ion. The luminescence in complexes is observed mainly because of (i) good sensitization of Sm(III) ion by auxiliary units (ii) removal of non-radiative deactivation routes by vibrations of O-H and N-H bonds. Various investigations reveal the similar structure of all the synthesized samarium complexes. The emissive properties of Sm(III) complexes show that these complexes might be utilized as good candidate in lighting and display sources.

Inexpensive bioluminescent genosensor for sensitive determination of DNA damage induced by some commonly used sunscreens

Sunscreens (SSs) are highly applied all over the world on large areas of human body. Benzophenone chemical group constitute a major part in most SSs. Benzophenones are reported to induce changes in nucleic acids upon UV-irradiation. These alterations may potentially lead to DNA mutation, cell apoptosis, and eventually skin cancer. This work compares the kinetics of the induced DNA damage by some SSs after UV-irradiation. Six commonly used SSs; 4-t-butyl-4-methoxy dibenzoyl methane, 4-methoxycinnamic acid, 2-hydroxy-4-methoxybenzophenone (BZ-3), Dibenzoyl methane, 2,2′-dihydroxy-4-methoxy benzophenone (BZ-8) and p-methylbenzoic acid; are investigated. In this work, terbium chloride bioluminescent genosensor is used for sensitive, simple and inexpensive determination of induced DNA-damage. Results reveal that only BZ-3 and BZ-8 induced DNA-damage upon UV-irradiation that are confirmed by both absorption spectroscopy and viscosity measurements. Moreover, viscosity studies indicated the possible intercalation of the SS into DNA prior to initiation of DNA damage. Furthermore, the potency of BZ-3 and BZ-8 to induce DNA damage upon UVA irradiation was assessed on calf thymus DNA. The low cost of the proposed bioluminescent genosensor allows it to be an automatic simple process for the investigation of any DNA-drug interactions without the need of coupling with other analytical methods.

Organometallic Magnesium Complex with Aggregation Induced Emission Properties: Synthesis, Characterization, and Fluorescent Fibers Applications.

In this work, a novel organomagnesium complex with outstanding aggregation induced emission (AIE) properties is synthesized using dibenzoylmethane (DBM) as the ligand. The structure of the complex is confirmed to be one magnesium ion coordinated to the dione groups of two DBM molecules, and the magnesium ion adopts a distorted octahedrally geometry. The obvious emission is found for Mg(DBM)2 powder and not in the solution, making this the first reported organomagnesium complex with AIE property. The properties of the complex were investigated by using UV-vis absorption and fluorescence emission spectroscopy, cyclic voltammetry, and density functional theory calculations. Moreover, the Mg(DBM)2 solution dispersed in filter paper was is colorless, which may be made into a convenient anti-counterfeiting and encryption tool. Mg(DBM)2 /alginate fibers were prepared by wet-spinning process and further processed into paper, which can be used in the fields of sensors, anti-counterfeiting, and encryption. Sweat contains a wealth of chemical information that could potentially indicate the body's deeper biomolecular state. The prepared fluorescent fibers were used to detect sweat due to its non-toxic, low-cost efficient and fast response to analytes.

Synthesis and photoluminescence characterization of the complexes of samarium dibenzoylmethanates with 1,10-phenanthroline derivatives

The eight coordinated complexes of samarium were synthesized with dibenzoylmethane (DBM) and bidentate auxiliary ligand. Ternary complexes of samarium of the type [Sm(DBM)3L] (L = 1,10-Phenanthroline or its derivatives) were prepared by one step method. These complexes were characterized by spectroscopic techniques and thermo-gravimetric analysis. The proton-NMR data of all the complexes are reliable with the coordination of three DBM units and one neutral unit. Luminescence spectra of the complexes taken in powdered form, illustrate the bright red luminescence at 648 nm upon UV excitation that is accredited to the 4G5/2→6H9/2 transition of Sm3+ ion. The domination of hypersensitive transition corresponding to 648 nm reflects the asymmetric environment around samarium ion and their intensity undergoes significant change on variation in the binding environment about metal ion. The intense luminescence and color coordinates demonstrate that the complexes might be used as promising candidate in displays and light emitting devices.