EtOH Solvent Research Articles

Synthesis, Structural Investigation and Biological Activity of a Heterocyclic Schiff-Base Ligand and Its Coordination Complexes

This study reports the formation, characterisation and biological evaluation of a Schiff base ligand and its corresponding metal complexes. The Schiff base ligand (HL) was prepared through a condensation reaction involving isonicotinohydrazide and N'-((1R,2R,4R,5S, E)-2,4-bis(4-chlorophenyl)-3-azabi cyclo[3.3.1]nonan-9-ylidene) isonicotinohydrazide (M) in EtOH solvent and (3-5) drops of conc. HCl. The interaction of HL with selected metal chlorides including Mn(+2), Co(+2), Ni(+2), Cu(+2) and Zn(+2) in a 2:1 (L:M) mole ratio resulted in the synthesis of complexes with the general formula [M(HL)Cl2] (where: M = Mn(+2),Co(+2) and Ni(+2)) and [M`(HL)Cl2] (where M` = Cu(+2) and Zn(+2)). The characterisation of the prepared compounds was carried out using a range of spectroscopic analyses, containing FT-IR and electronic spectroscopy, NMR (1H and 13C), mass spectrometry, atomic absorption, as well as a range of analytical techniques to fully characterise the title compounds, including elemental microanalysis (C.H.N) for elemental composition determination, chloride percentage analysis, conductivity measurements to assess electrical conductivity in solution, magnetic moments to investigate the magnetic properties and melting point determination. These spectroscopic and analytical techniques were involved in validating the identity and structural properties of both the ligand and its corresponding coordination compounds. Besides the structural characterisation, the biological evaluation of the synthesised compounds toward both G+ and G- bacterial strains was assessed. This investigation sheds light on the potential applications of these compounds in combating bacterial infections.

Quinazolinone-to-Isoquinoline Metamorphosis by Ruthenium-Catalyzed [4+2] Annulation with Sulfoxonium Ylides.

Molecular editing of quinazolinones to isoquinolines by a novel ruthenium-catalyzed [4+2] annulation with sulfoxonium ylides has been developed. The method permits the precise and rapid assembly of multisubstituted aminoisoquinolines, a class of heterocycles that play a privileged role in organic synthesis and pharmaceutical development. This new catalytic process exhibits novel programmability, including directed C-H acetylation, nucleophilic cyclization, and alcoholysis. Remarkably, various 2-arylquinazolinones and sulfoxonium ylides could be employed in excellent yields with broad functional group tolerance. This heterocycle-to-heterocycle protocol is compatible with green chemistry using an EtOH solvent and releasing H2O and dimethyl sulfoxide as byproducts.

N‐Carbamimidoyl‐2,2,2‐Trifluoro‐N′‐Arylacetimidamides as Important Intermediates for the Synthesis of 3‐Amino‐4‐Aryl‐5‐(Trifluoromethyl)‐1H‐1,2,4‐Triazoles

ABSTRACTA novel series of N‐carbamimidoyl‐2,2,2‐trifluoro‐N′‐arylacetimidamides (3a–j) have been prepared via condensation of 2,2,2‐trifuoroacetimidoyl chlorides with guanidine in the presence Na and in dry EtOH solvent at ambient temperature. Then, these key intermediates were applied for the synthesized of 3‐amino‐4‐aryl‐5‐(trifluoromethyl)‐1H‐1,2,4‐triazoles (4a–j) under oxidative cyclization reaction in the presence of KI/I2 as an oxidant system and DMSO solvent. The target compounds were produced in high yields and without the need for isolation.

METHOD VALIDATION FOR DETERMINATION OF KYNURENIC ACID CONTENT IN NATURAL PRODUCTS BY RP-HPLC-UV

Kynurenic acid (KYNA) is a metabolite with pharmacoactive properties found primarily in chestnut honey, linden, and other honeys. Considering the anti-inflammatory and immunosuppressive functions of KYNA, it can be seen that it has bidirectional effects on biological pathways. For this reason, determining and knowing the amount of honey, an important natural product can have a high impact on health. Studies on the detection of this metabolite in both natural products and animal tissues are ongoing, and it is important to develop fast and easily applicable methods. Within the scope of this study, a new method was created using an ultraviolet detector (RP-HPLC-UV) in reverse-phase high-performance liquid chromatography to determine the KYNA content of natural products (honey, chestnut pollen, and chestnut flowers) quantitatively in a short time. According to the data obtained, LOD and LOQ values were found to be 0.030 µg/mL and 0.092 µg/mL, respectively. At the same time, solutions of KYNA prepared in ultrapure water (UPW), 70% EtOH, EtOH and MeOH solvents were analyzed in this method, and it was found that UPW was the best solvent. The findings of this research can contribute significantly, particularly in the application of measuring KYNA, to distinguishing the botanical origin of chestnut honey.

Launaea cornuta (wild lettuce) leaf extract: phytochemical analysis and synthesis of silver-zinc oxide nanocomposite

Access to quality drinking water is an essential human right and a fundamental aspect of human dignity, yet a challenge to many in developing countries. Over 2 billion people worldwide lack access to quality drinking water due to microbial contamination, among other factors. Silver-doped zinc oxide impregnated activated carbon nanocomposites, Ag-ZnO-AC NCs, a strong antimicrobial agent have been used at point-of-use to treat water treatment. Green synthesis of Ag-ZnO-AC NCs has played a vital role since it leads to the acquisition of non-toxic nanocomposites compared to chemical synthesis. In this study, Ag-ZnO-AC NCs were green-synthesized using Launaea cornuta leaf extract as a source of reducing and capping agents in place of synthetic chemicals. Antioxidants from Launaea cornuta (Wild Lettuce) leaves were extracted using 0, 50, and 100% EtOH solvents with different volumes and extraction circles. The highest phenolic (11044 ± 63 μg) and antioxidant (44112 ± 894 μg) contents were extracted using 50% EtOH and 20 ml of extract solvent with p < 0.05. The SEM and TEM images of the synthesized Ag-ZnO-AC NCs show the formation of highly porous AC with sheet-like structures and successful Ag-ZnO NCs impregnation within the pores and on the surface of the AC. Based on the inhibition zone, the antimicrobial activity of the Ag-ZnO AC NCs had significant results with 14.00 ± 0.37 for E. coli and 17.33 ± 0.36 mm for S. aureus, p < 0.05. These results confirm the significance of Launaea cornuta (Wild Lettuce) as a source of antioxidants that can be used as reducing and capping agents to synthesize Ag-ZnO-AC NCs.

Fe3O4 nanoparticles impregnated eggshell as an efficient biocatalyst for eco-friendly synthesis of 2-amino thiophene derivatives

In this study, a biodegradable and eco-friendly biocatalyst (eggshell/Fe3O4) was synthesized utilizing eggshell impregnated with Fe3O4 nanoparticles. The characterization of prepared catalyst was carried out by Fourier transform infrared radiation (FT-IR), scanning electron microscopy (SEM), X-ray Diffraction (XRD), energy-dispersive X-ray (EDX), thermal gravimetric analysis-differential thermogravimetry (TGA-DTG), vibrating sample magnometer (VSM), and atomic force microscopy (AFM). The eggshell/Fe3O4 biocatalyst was served in multi-component reactions (MCRs) for the synthesis of 2-amino thiophene derivatives from variety aromatic aldehydes, malononitrile, ethyl acetoacetate, and sulfur (S8). To achieve optimal reaction conditions, a thorough examination was conducted on key factors, such as the solvent type, reaction time and temperature, and the ratio of eggshell to Fe3O4. The findings suggest that high yield product can be obtained at microwave temperature (MW) in EtOH solvent within 10 min. Additionally, the eggshell/Fe3O4 biocatalyst exhibited high catalytic activity, which was sustained over the five cycles, without any significant decline in its performance.

A Torquoselective Thermal 6π-Electrocyclization Approach to 1,4-Cyclohexadienes via Solvent-Aided Proton Transfer: Experimental and Theoretical Studies.

The thermal 6π-electrocyclization of hexatriene typically delivers 1,3-cyclohexadiene (1,3-CHD). However, there is only limited success in directly synthesizing 1,4-cyclohexadiene (1,4-CHD) using such an approach, probably due to the difficulty in realizing thermally-forbidden 1,3-hydride shift after electrocyclic ring closure. The present study shows that by heating (2E,4E,6E)-hexatrienes bearing ester or ketone substituents at the C1-position in a mixture of toluene/MeOH or EtOH (2 : 1) solvents at 90-100 °C, 1,4-CHDs can be selectively synthesized. This is achieved through a torquoselective disrotatory 6π-electrocyclic ring closure followed by a proton-transfer process. The success of this method depends on the polar protic solvent-assisted intramolecular proton transfer from 1,3-CHD to 1,4-CHD, which has been confirmed by deuterium-labeling experiments. There are no reports to date for such a solvent-assisted isomerization. Density functional theory (DFT) studies have suggested that forming 1,3-CHD and subsequent isomerization is a thermodynamically feasible process, regardless of the functional groups involved. Two possible successive polar solvent-assisted proton-transfer pathways have been identified for isomerization.

ENHANCING REACTION EFFICIENCY IN THE GREEN PREPARATION OF 2-(2-OXOINDOLIN-3- YLIDENE)MALONONITRILES WITH ULTRASOUNDASSISTED KNOEVENAGEL CONDENSATION

The development of 2-(2-oxoindolin-3-ylidene)malononitrile analogs has been quantitatively reported using an exceedingly feasible green methodology. This protocol involves the Knoevenagel condensation of various isatins and indeno[1,2-b]quinoxalin-11-nones with malononitrile in a solvent of EtOH under ultrasonic irradiation. This method significantly enhances the reaction efficiency, offering enormous yields ranging from 80% to 96% for the target products within a remarkably short reaction time of 10 to 15 minutes at ambient temperature. The synthesized 2-(2-oxoindolin-3-ylidene)malononitrile analogs were meticulously validated using NMR and FTIR spectroscopic analysis, confirming their structures. The methodology employed not only achieves exceptional yields but also features several green chemistry advantages, including simple workup procedures, the absence of column chromatography, the use of eco-friendly solvent, high tolerance for functional groups, and rapid reaction times at ambient temperature. This ultrasound-assisted approach underscores the importance of sustainable practices in chemical synthesis by minimizing energy consumption and reducing the use of hazardous reagents. The findings highlight the potential of this green protocol to be widely applicable in the development of various 2-(2-oxoindolin3-ylidene)malononitrile analog promoting both efficiency and environmental sustainability in organic chemistry.

Green approach to new library of 1,8-naphthalimide fluorophores employing C-C and C-N cross coupling reactions by novel, durable, and reusable magnetic nanocatalyst bearing nickel (0) complex of 1,10-phenanthroline

The novel light cayn to yellow fluorescent 1,8-naphthalimide-based compounds with benzothiophene, benzofuran, aryl, and amino substituent at the C-4 position were successfully synthesized in excellent yields (up to 97 % yield) via the catalysed Suzuki coupling and carbon–nitrogen cross coupling reactions using a novel heterogeneous super nanomagnetic Ni-catalyst system bearing fortified 1,10-phenanthroline ligand (Fe3O4@SiO2-Phen-Ni(0)) under mild conditions. The structure of synthesized magnetic nanocatalyst was identified by FT-IR, XRD, FESEM, DLS, TEM, VSM, TGA-DSC, EDX, mapping images, ICP, and UV–Vis techniques, which exhibited high efficiency in the synthesis of these C-4 π-conjugated and amino fluorophore 1,8-naphthalimide materials with low Ni-contamination. The nanocatalyst with the aid of an external magnet could be easily recovered and reused for up to nine consecutive runs without significant decline in its activity. UV–Vis absorption and fluorescence emission spectrum of these derivatives were collected. All these compounds can emit light cay, greenish-yellow or yellow emission and show a large Stokes shift (νa-νf up to 8900 cm−1), longer λ emission (λem up to 541 nm), and fluorescence quantum yield (Qf) (up to 0.89) due to the extended conjugation system. The provided data of Suzuki derivatives reveal the highest Qf and λem in EtOH solvent, and 4-amino-1,8-naphthalimide derivatives exhibit, the highest Qf data in DCM solvent, and the largest emission wavelength in acetonitrile, and the highest data of Stokes shift in EtOH. Furthermore, the positive solvatochromic behavior, corresponding to bathochromic shift with increasing solvent polarity, in new C4-aryl/ heteroaryl/ and amino 1,8-naphthalimide frameworks was shown.

Anion cascade reactions III: Synthesis of 3-isoquinuclidone bridged polycyclic lactams

Bridged polycyclic lactams are important structural units in organic functional materials, natural products, and pharmaceuticals. A flexible and efficient anion cascade reaction was developed for the preparation of bridged polycyclic lactams from readily available malonamides and 1,4‑dien-3-ones. Various highly substituted bridged polycyclic lactams were synthesized in good to excellent yields by tandem nucleophilic sequences in the presence of tBuOK in commercially available EtOH solvent at 60 °C. Notably, the simple reactions can be run on a gram scale. Mechanistically, bis-Michael addition reaction and hemiaminalization reactions are involved in the tandem transformation.

Novel dinuclear Ni (II) Schiff base complexes induced noncovalent exchanges: Crystal structure investigation, electrochemical assessment, Hirshfeld surface analysis and SARS‐CoV‐2 docking study

In this work, novel Ni (II) complexes, namely, [Ni2(L)2(OAc)2(EtOH)2] (1a), [Ni2(L)2(OAc)2(H2O)2] (1b‐1) and [Ni2(L)2(OAc)2(EtOH)2] (1b‐2) as co‐crystal were synthesized by the 1:1 condensation (https://www.sciencedirect.com/topics/chemistry/condensation) of Ni (CH3COO)2·4H2O and Schiff base ligand (H2L) (2‐hydroxy‐4‐methoxybenzaldehyde and 2‐amino‐2‐methylpropanol). The ligand based on Schiff base and fabricated complexes (1a) and (1b‐1 and 1b‐2) were successfully identified by CHN assessment, FT‐IR, UV–Vis spectra, melting point and CV voltammogram. The electrochemical behavior investigation shows that the nickel complexes exhibited irreversible oxidation processes in methanol solution. Additionally, the crystal structures of complexes (1a) and (1b) have been recognized by single‐crystal X‐ray diffraction investigation. It turned out that the complexes (1b‐1) and (1b‐2) crystallize together, making a co‐crystal 1b with an additional EtOH solvent molecule in the crystal structure. A detailed study of intermolecular exchanges was performed using attractive graphical analysis tools such as three‐dimensional Hirshfeld surfaces analysis, two‐dimensional fingerprint plots (FPs), and enrichment ratios (E), which make C‐H … C, C‐H … O hydrogen bond, C … O, H … H, and O … O short contacts on Hirshfeld surfaces with color code are observed. Moreover, an appraisement of the inhibitory trace against coronavirus (main protease SARS‐CoV‐2, PDB ID: 6Y2F) and molecular targets of human angiotensin‐converting enzyme‐2 (ACE‐2) was performed by a molecular docking study in which two nickel complexes performed best for PDB protein ID: 6M0J and all three complexes for PDB protein ID: 6Y2F.

Oyster shell powder-gold nanoparticle composites as a reactive, recyclable, and green catalyst

Oyster shell waste can be utilized as a colloidal solid support to anchor abundant gold nanoparticles (AuNPs) for use as a highly selective, reactive, and recyclable catalyst in C-C bond forming reactions under base-free green reaction conditions. A deposition precipitation method is utilized to effectively incorporate sub-10 nm AuNPs onto the ground oyster shell powder (OSP). Although the loaded AuNPs mainly possess bare surfaces without any capping agents, the resulting composite particles exhibited great dispersity and stability in various solvents, including EtOH and water. After examining their structural and compositional properties, the composite particles are tested as a catalyst in C-C bond forming reactions. These composite particles reveal an unexpectedly high reactivity and selectivity in the homocoupling of arylboronic acid without using any additives, including necessary inorganic bases. This is presumably because the abundant carbonate groups around the OSP surfaces can effectively play a role as a base, while the bare surfaces of the incorporated AuNPs act as catalytically reactive sites. In addition to these synergistic features of the composite particles, establishing reliable reaction conditions requiring only reactants in a green EtOH solvent results in the easy isolation of the product and catalyst, yielding great recyclability. The utilization of marine wastes along with biocompatible and catalytically active metal nanoparticles will lead to the development of economical multi-purpose catalysts that are extremely practical and recyclable in eco-friendly reaction conditions.

Exploration of catalytic activity of newly developed Pd/KLR and Pd-Cu/KLR nanocomposites (NCs) for synthesis of biologically active novel heterocycles via Suzuki cross-coupling reaction

The present articles aimed at the synthesis of biologically active novel heterocycles via selective construction of CC bond through a cross-coupling reaction between a heterocyclic aryl halide and phenylboronic acid catalyzed by the newly developed Pd-KLR (Palladium-Kaphal leaves residue) and Pd-Cu-KLR nanocomposites (NCs). The biological properties of the newly synthesized heterocycles were examined using molecular docking studies. Pd-KLR nanocomposites (NPs) and Pd-Cu/KLR nanoparticles (NCs) were synthesized using kaphal (box berry) leaves extract, the extracted residue of kaphal leaves is used as a carrier and reducing agent in the cross-coupling reaction. The synthesized Pd NCs and Pd-Cu NPs were characterized using FT-IR, UV-visible, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. Molecular docking results revealed that the newly synthesized heterocycles exhibit impressive affinity towards bacterial topoisomerase II that indicated their antibacterial properties. The cluster Pd-KLR NCs and spherical Pd-Cu-KLR NPs had a mean particle size of around 110 nm and 53 nm. The comparative study of both Pd-KLR and Pd-Cu-KLR nanocatalysts is studied. However, the heterogeneous Pd-KLR nanocomposite showed excellent catalytic activity for the heterocyclic Suzuki Cross-Coupling reaction. The yield of the reaction of 3-amino-2-chloropyridine with phenylboronic acid using EtOH solvent in the presence of NaOH base and a very little amount of Pd0.02/KLR (0.1 mmol%) catalyst at 78 °C temperature under microwave irradiations for 10 min is noticed as 96.7%. Furthermore, the catalyst could be recycled for up to seven cycles without any significant activity loss.

Exploring the excited state proton transfer mechanisms of flavonoid probe in three representative solvents

The role of intermolecular hydrogen bond is often ignored in the study of the solvent effect on the excited state proton transfer (ESPT) processes. The ESPT mechanisms of 2-(4-(dimethylamino)phenyl)-3‑hydroxy-6,7-dimethoxy-4H-chromen-4-one (HOF) in three representative solvents, which were toluene, dimethyl sulfoxide (DMSO) and ethanol (EtOH), were investigated through time-dependent density functional theory (TD-DFT) method, and the effect of intermolecular hydrogen bond on the ESPT was fully considered in this paper. The results show that the enhancement of intra- and inter-molecular hydrogen bonds is the key factor of proton transfer process. The change of electron density distribution is also more conducive to the ESPT processes. Due to the existence of intermolecular hydrogen bond in HOF-DMSO complex, the energy barrier of ESPT in DMSO is higher than that in toluene. In EtOH solvent, the excited state double proton transfer (ESDPT) reaction can occur between HOF and EtOH along two different reaction channels with the assistance of dual intermolecular hydrogen bonds. Although the ESPT modes in DMSO and EtOH solvents are different, the energy barriers are basically the same. The energy barriers of ESPT processes in two polar solvents increase obviously due to intermolecular hydrogen bond. Moreover, in polar solvents, a relatively large red-shift was observed in the fluorescence spectra.

Solvent effect on adsorption of benzylidene oxindole to C20 nanocage: A DFT approach

AbstractIn this paper, one of the selective and potent inhibitors named (E)‐3‐benzylidene‐indoline‐2‐one (I), as against different receptor tyrosine kinase in metastasis, angiogenesis, and tumor growth, is inspected in the gas phase and in solution, at B3LYP/6‐311++G** and B3LYP/AUG‐cc‐pVTZ level of theory. A stimulating issue for this biologically active species is the effect of different media on its stability, structure, and energy gap in intermolecular [4 + 2] adsorption of I (as diene) to C20 (as dienophile) to yield (E)‐3‐benzylidene‐indoline‐2‐one[20]fullerene: Ia complex. In going from gas phase to C6H6, C2H4Cl2, EtOH, MeNO2, DMSO, and H2O solvents, individually, the optimization of complex (Ia) leads to the following: (1) The thermodynamic stability; the adsorption energy difference between liquid and gas phase (∆El–g) and dipole moment (μ) seem proportional to the dielectric constant (ε) of the scrutinized media. (2) The kinetic stability; energy difference (∆EL–H) between the frontier molecular orbitals; FMO in different media is altered in the opposite direction of ε. (3) Despite of popular belief that the endo isomer emerges thermodynamically more stable than its corresponding exo isomer, we suggest formation of kinetically more stable exo isomer because of π–π stacking among the benzyl ring and C20 nanocage. (4) The possibility of hetero [4 + 2] cycloaddition is anticipated by the lowest energy barrier of 3.8 kcal/mol probed for exo transition state (TS) in gas phase, while the highest energy barrier of 7.9 kcal/mol corresponds to the endo TS in water. (5) Due to lack of the repulsion type interaction, the exo [4 + 2] cycloaddition of unstable C20 fullerene with the scrutinized oxindole can be carried out thermally at r.t. and currently hold responsible for the origin of stereoselectivity.

A Multimodal Desorption Electrospray Ionisation Workflow Enabling Visualisation of Lipids and Biologically Relevant Elements in a Single Tissue Section.

The colocation of elemental species with host biomolecules such as lipids and metabolites may shed new light on the dysregulation of metabolic pathways and how these affect disease pathogeneses. Alkali metals have been the subject of extensive research, are implicated in various neurodegenerative and infectious diseases and are known to disrupt lipid metabolism. Desorption electrospray ionisation (DESI) is a widely used approach for molecular imaging, but previous work has shown that DESI delocalises ions such as potassium (K) and chlorine (Cl), precluding the subsequent elemental analysis of the same section of tissue. The solvent typically used for the DESI electrospray is a combination of methanol and water. Here we show that a novel solvent system, (50:50 (%v/v) MeOH:EtOH) does not delocalise elemental species and thus enables elemental mapping to be performed on the same tissue section post-DESI. Benchmarking the MeOH:EtOH electrospray solvent against the widely used MeOH:H2O electrospray solvent revealed that the MeOH:EtOH solvent yielded increased signal-to-noise ratios for selected lipids. The developed multimodal imaging workflow was applied to a lung tissue section containing a tuberculosis granuloma, showcasing its applicability to elementally rich samples displaying defined structural information.

Tandem Protocol of Hexahydroquinoline Synthesis Using [H2-DABCO][HSO4]2 Ionic Liquid as a Green Catalyst at Room Temperature.

Green, eco-benign, and sustainable synthesis is paramount in present chemistry. Here, a facile, efficient, and [H2-DABCO][HSO4]2 ionic-liquid-catalyzed one-pot multicomponent synthesis of hexahydroquinolines was reported under ambient reaction conditions. The reaction of 1,3-dicarbonyls, malononitrile, and ammonium acetate with various aldehydes in the presence of an ionic liquid catalyst and EtOH solvent at room temperature afforded excellent yields (76-100%) of hexahydroquinolines under a short reaction time (5-15 min). Mild reaction conditions, broad substrate scope (28 derivatives), and column-chromatography-free synthesis with excellent catalytic efficiency and good recyclability rendered this protocol superior and practical. The greenness of the present method was assessed through eco-score and E-factor. The significant results in gram-scale synthetic conditions validate its applicability in industries as well as academia in the near future.

Eksperimentalno ispitivanje tehnoloških parametara biljnih droga za proces ekstrakcije i destilacije

The parameters of herbal drugs that are important for technological processes, especially for extraction and distillation processes were examined: bulk density, tapped density, compressibility index, Hausner ratio, and solvent absorption power. The methods described in the pharmacopoeia were used for the examination. Based on the values of bulk density and tapped density, the volume of the device is planned, ie. the size of the batch for extraction or distillation. These parameters were shown to have lower values for flower, leaf and herb, and higher values for fruit and root. Also, the compressibility index depends on the degree of fragmentation and the Hausner ratio. The results showed that these parameters have lower values for fruit and root. Solvent absorption power is the volume of solvent absorbed by a certain amount of herbal drug. Two solvents with differences in concentration were used: ethanol (aqueous solution: 96 vol.%, 70 vol.% and 50 vol.%) and distilled water. At the end of the technological process, a part of the solvent/ extract can be extracted from the spent plant material by pressing or vacuum filtration. The other part is difficult to get rid of the spent plant material and is irreversibly thrown away. In all tested herbal drugs, it is noticeable that the solvent absorption power increases with the increasing polarity of the solvent. Also, the less polar solvent EtOH 96% is more selective in terms of plant part. As the polarity of the solvent increases, it does not matter which part of the plant is extracted.

Preparation, AIE and ESIPT behaviour, controllable solid-state fluorescence and application of Co2+ probe based on α-cyanostilbene

A simple α-cyanostilbene-functioned salicylaldehyde-based Schiff-base probe, which exhibited outstanding ‘aggregation-induced emission and excited state intramolecular proton transfer (AIE + ESIPT)’ emission in solution, aggregation and solid states, was synthesized in high yield of 87%. Its solid-states with different morphologies emitted different fluorescence after crystallization in EtOH/H2O (1/2, v/v) mixtures or pure EtOH solvent. Besides, it exhibited an obvious spectro-photometrical fluorescence quenching for highly selective sensing of Co2+ in THF/water system (ƒw = 60%, pH = 7.4), accompanied by an intense green fluorescence turn-off behavior under UV365nm illumination. The binding stochiometry between the ligand and Co2+ was found to be 2:1, and the detection limit (DL) was calculated to be 0.41 × 10−8 M. In addition, it could be applied to detect Co2+ in real water samples and on silica gel testing strip.

Synthesis, characterization and band gap energy of new water soluble fluorescent diethanolamine-boron-subphthalocyanine dye using B nanoparticles and SiB6 microparticles

In the present work, the novel synthesis methods were developed for the preparation of a new water soluble and fluorescent diethanolamine-boron-subphthalocyanine (Dea-B-SubPc) dye. The boron nanoparticles and SiB6 were utilized as the boron sources for the Dea-B-SubPc synthesis. In order to obtain the boron nanoparticles, the powder mixture of boron microparticles, phthalonitrile (Pn) and KCl was encapsulated into a Cu pipe and then mechanically roll-milled at room-temperature. The Dea-B-SubPc dye was synthesized via the reaction of the roll-milled boron nanoparticles and Pn in 50 % Dea-toluene solution at 120 °C. The Dea-B-SubPc was also synthesized by the reaction of Pn and SiB6 microparticles using similar experimental conditions. The prepared Dea-B-SubPc was characterized by using the SEM, FT-IR, NMR, HR-ESI-MS, cyclic voltammetry (CV), UV–vis. absorption and fluorescence (FL) emission spectroscopy. The Dea-B-SubPc is soluble in H2O, DMSO, MeOH and EtOH solvents. The optical band gap energy of the Dea-B-SubPc was found as 2.15 eV in MeOH and H2O, and 2.10 eV in DMSO. The Dea-B-SubPc solutions exhibited FL emissions at 592.2 nm in DMSO, 575.2 nm in MeOH and 577.8 nm in H2O with the excitation at 450 nm. The EHOMO and ELUMO energy levels of the Dea-B-SubPc were calculated as −5.82 eV and −4.08 eV, respectively and then the electrochemical band gap energy was found as 1.74 eV using the CV measurements. In summary, both the B nanoparticles and SiB6 microparticles were used successfully for the synthesis of the Dea-B-SubPc as a new fluorescent and low band gap energy dye material.