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These structurally isomeric rhodamine 6G-based amino derivatives are designed to detect Sn2+ ions. The receptors exhibit rapid fluorescent “turn-on” responses towards Sn2+. The absorption (530 nm) and fluorescent intensity (551 nm) of the receptors increase when increasing the concentration of Sn2+. The hydrazine derivative exhibits more rapid sensitivity towards Sn2+ than the ethylene diamine derivative, indicating that the presence of an alkyl chain in the diamine decreases the sensitivity of the receptors towards Sn2+. The presence of carbonyl groups and terminal amino groups strongly influences the sensitivity of the chemosensors toward Sn2+ by a spirolactam ring-opening mechanism. The receptors exhibit 1:1 complexation with Sn2+ as evidenced by Job plot, and the corresponding limit of detection was found to be 1.62 × 10−7 M. The fluorescence images of the receptors and their complexes reveal their potential applications for imaging of Sn2+ in real/online samples.

This work demonstrates the successful polymerization of N-vinyl caprolactam using dual-sited phase-transfer catalyst and potassium persulfate as conventional radical initiator in cyclohexane-aqueous media at 60 ± 2 °C under normal and ultrasound environment with 45 kHz power of 550 W. Dual-sited phase-transfer catalyst acts as a gear to accelerate the reaction in a two-phase system and along with ultrasound circumstance reaction rate was effectively improved. We observed that the polymerization rate was significantly increased with an increase of concentration of different reaction parameters and also presence of ultrasound environment rate was doubled than with normal condition. Activation energy value of polymerization reaction validates the doubling of polymerization rate. The various reaction parameters (frequency, monomer, initiator, catalyst, and temperature) on the polymerization rate were explored under normal and ultrasound condition. Acquired poly(N-vinyl caprolactam) was validated and characterized by different analyses.

Novel substituted series of aromatic copolymers was obtained by one-spot, metal-free super acid-catalyzed one-step polymerization of substituted isatin and phenothiazine. The polymerization reaction was performed at room temperature in the presence of Bronsted superacid (trifluoromethanesulfonic acid) and methylene chloride which condenses the compounds consists of carbonyl group (aldehydes and ketones) and aromatic rings to yield the polymers. Super acid catalyst has several advantages including the reaction proceeding at room temperature and great synthetic versatility. The obtained polymers have good solubility in common organic solvents. The polymers were purified by repeated precipitations with methanol. Polymers (P1–P3) were completely characterized by FT-IR, 1H NMR, TGA, and UV–visible, fluorescence and cyclic voltammetry techniques. Polymers (P1–P3) possessed excellent thermal stability up to 300 °C and have absorbance and emission maximum at 557 and 630 nm, respectively. The optical and electrochemical properties of these polymers revealed that it could be one of the capable materials for applications in optoelectronic device and in the area of proton exchange membrane fuel cell.

Leakage-free, thin molecular dielectric layers with sizable macroscopic polarization are valuable for organic field-effect transistor applications. Molecules that are designed for large polarizabil...

Methyl and ethyl methacrylate was polymerized in heterogeneous system with the help of newly synthesized multi-site phase-transfer catalyst and using water-soluble initiator at 60 ± 1 °C under unstirred inert atmospheric condition. Polymer yield was increased with increasing molar concentrations of monomer, initiator, catalyst and temperature. Polymerization follows first-order kinetics with respect to monomer and half-order with respect to catalyst and initiator, respectively. PTC has myriads of applications in the synthesis of various organic and polymeric materials because of its fast reaction and high yield in short period of time. Without addition of PTC, polymerization did not occur; this indicates that catalyst plays the pivotal role on initiation of polymerization. It extracts the reactive radical anion from aqueous phase and transfers to the organic phase where acrylates were polymerized. Polymerization reactivity of methyl and ethyl methacrylate under PTC conditions was studied by various parameters. The activation energy (Ea) and other thermodynamic parameters were calculated. The Ea value supports the reactivity of acrylates. The results obtained from this investigation were used for inferring the radical mechanism of phase-transfer-catalyzed polymerization. The obtained polymers were analyzed by spectral and thermal analyses.

In this work, we synthesized series of polymers (P1 – P4) having two different alkyl side-chains linked in phenothiazine-isatin (PTz-IS) moieties using super acid (trifluoromethanesulfonic acid) catalyst at ambient condition. The effects of alkyl chain length on the polymers of phenothiazine (electron-donating moiety) and isatin (electron-withdrawing moiety) were investigated and compared without side chain of their counterpart. Synthesized alkylated P1 - P4 showed very good solubility in all common organic solvents and forms smooth film on glass substrate on compared to non-alkylated polymers. P1 – P4 were fully analyzed by FT-IR, 1H NMR, TGA, UV-Visible, fluorescence and cyclic voltammetry techniques. An alkylated and non-alkylated polymer was possessing thermal stability of 244°C and 300 °C respectively. The absorbance and emission maximum of alkylated and non-alkylated polymers based on phenothiazine –isatin was showed at 561, 637 nm and 557, 630 nm respectively. Likewise the all the properties was compared and discussed with proper explanation. From the obtained results, P1-P4 could be suitable materials for optoelectronics device and other relevant applications.

An ultrasound condition associated with phase-transfer catalyst (PTC) has great diverse applications in synthesis of various organic and polymeric materials because of its fast reaction and high yield in short period of time. Phase transfer catalyst (cetyltrimethylammonium bromide as PTC) extracts the reactive radical anion from aqueous phase and transfer to organic phase whilst ultrasound condition enhances the radical formation; consequently, acrylonitrile was polymerized in ethyl acetate/water two-phase system at 60 ± 1 °C under ultrasound (25 kHz/300 W) and silent condition. The rate of polymerization (R p) was doubled under ultrasound compare to silent condition. The various experimental parameters such as monomer, initiator, catalyst and temperature, solvent polarity on the rate of polymerization was studied in both conditions. The activation energy (E a) and other thermodynamic parameters were calculated. The E a value of ultrasound condition supports the enhancement of rate of polymerization. On the basis of observed results, a suitable kinetic model, mechanism and effect of ultrasound in the rate of polymerization were discussed. The obtained polymer was analyzed by TG/DTA and FT-IR. The viscosity average molecular weight of the polymer was found to be 6.8526 × 104 g mol−1.

An ultrasonic condition assisted phase transfer catalyzed radical polymerization of methyl methacrylate was investigated in an ethyl acetate/water two phase system at 60 ± 1 °C and 25 kHz, 300 W under inert atmosphere. The influence of monomer, initiator, catalyst and temperature, volume fraction of aqueous phase on the rate of polymerization was examined in detail. The reaction order was found to be unity for monomer, initiator and catalyst. Generally, the reaction rate was relatively fast in two phase system, when a catalytic amount of phase transfer catalyst was used. The combined approach, use of ultrasonic and PTC condition was significantly enhances the rate of polymerization. An ultrasonic and phase transfer catalyzed radical polymerization of methyl methacrylate has shown about three fold enhancements in the rate compared with silent polymerization of MMA using cetyltrimethylammonium bromide as PTC. The resultant kinetics was evaluated with silent polymerization and an important feature was discussed. The activation energy and other thermodynamic parameters were computed. Based on the obtained results an appropriate radical mechanism has been derived. TGA showed the polymer was stable up to 150 °C. The FT-IR and DSC analysis validates the atactic nature of the obtained polymer. The XRD pattern reveals the amorphous nature of polymer was dominated.

This work establishes the kinetics of radical polymerization of methyl methacrylate in an aqueous–organic two-phase system using 1,4-bis (triethylmethylammonium) benzene dichloride (TEMABDC) as multi-site phase transfer catalyst and potassium peroxydisulphate (K2S2O8) as water-soluble initiator at 60 ± 1 °C under nitrogen atmosphere. The role of concentrations of monomer, initiator, catalyst, acid and ionic strength, temperature and volume fraction of aqueous phase on the rate of polymerization (R p) was investigated. The rate of polymerization (R p); R p α [MMA]0.64, [TEMABDC]1.24 and [K2S2O8]1.50. The rate of polymerization increases with an increase in the concentration of monomer, initiator, catalyst and temperature. A generalized reaction model was developed to explain the phase transfer catalyzed polymerization reaction. Based on the kinetic results, radical mechanism has been derived. The activation energy and other thermodynamic parameters were calculated. The FT-IR spectroscopy validates a band of 1732 cm−1 of ester group of the obtained polymer. The viscosity average molecular weight of the PMMA was found 1.6955 × 104 g/mol.

The corrosion inhibition efficiency of newly synthesized Schiff bases, SB-1 [(4E)-N-((Z)-2-((furan-2-yl)methylimino) indolin-3-ylidene)(furan-2-yl)methanamine] and SB-2 [(7Z,8Z)-6-chloro-N2,N4-bis(1-(pyridin-2-yl)ethylidene)pyrimidine-2,4-diamine], was investigated for aluminium corrosion in 1 M H2SO4 medium using mass loss and electrochemical techniques. Potentiodynamic polarization curves show that addition of Schiff bases in the acid solution shifts the corrosion potential (Ecorr) towards positive direction, suggesting that chosen SBs are performed as mixed-type inhibitiors. The adsorption process of Schiff bases on aluminium surface obeys Langmuir isotherm. Further, electrochemical impedance studies (EIS) reveal that the inhibition efficiency remarkably rises with increasing SBs concentration and the maximum inhibition efficiencies of 97% and – 95% were obtained for SB-1 and SB-2, respectively, for the inhibitor concentration of 500 ppm. Additionally, the associated activation parameters and thermodynamic data of adsorption were evaluated. Scanning electron microscope (SEM) studies further confirm that ligands of SB-1 and SB-2 have a strong tendency to adhere on top of aluminium and protect its corrosion against acidic media. The SEM micrographs of corroded and inhibited aluminium surfaces and the maximum inhibition efficiency of aluminium corrosion are achieved to be 97% for Schiff bases (SB-1) in 1 M H2SO4 solution with the concentration of 500 ppm.

Carbazole—containing motifs are of most desired materials because of its wide range of applications due to π- extended systems, molecular and optical properties was easily tunable via diverse structural modifications. Herein, we reported an efficient and facile polymerization of N-vinyl carbazole (NVK) using multi-site phase transfer catalyst with and without ultrasound condition. The rate of polymerization (Rp) was effectively improved with ultrasound in short time on compare with silent condition. Role of different parameters such as variation of frequency, monomer, initiator, catalyst and temperature, solvents, aqueous and pH on the rate of polymerization of NVK was explored under silent and ultrasound condition (45 kHz/550 W). Activation energy of polymerization was supported for an enhancement of rate under ultrasound condition. From the experimental results, an appropriate kinetic model and role of various parameters in polymerization reaction was discussed. The obtained poly (N-vinyl carbazole) was confirmed and characterized by FT-IR, 1H NMR, TGA and XRD techniques.

The kinetics of radical polymerization of butyl acrylate initiated by potassium peroxydisulphate and cetyltrimethylammonium bromide as phase transfer catalyst (PTC) was carried out under inert and unstirred conditions at constant temperature of 60 ± 2 °C in ethyl acetate–water biphase media. The polymerization reactions were relatively fast in the two-phase systems with phase transfer agent whereas extremely sluggish in the system without PTC. Use of PTC accelerates the reaction effectively if the reactants located in two phase. The effects of rate of polymerization (R p) on various experimental conditions such as different concentrations of monomer, initiator, phase transfer catalyst, temperature, and different ionic strength of the medium were explored. The order with respect to monomer, initiator and phase transfer catalyst was found to be unity. The R p is independent of ionic strength and pH of the medium. However, an increase in the polarity of solvent has slightly increased the R p value. Based on the results obtained, a plausible mechanism has been proposed for the polymerization reaction. The obtained polymer was confirmed by FT-IR analysis.

In this paper, corrosion inhibition ability of Borassus flabellifer coir dust thus extracted by water (BFDWE) and methanol (BFDME) against aluminum in 1 M H2SO4 at 303–333 K has been examined using electrochemical, non-electrochemical, and microstructural analysis. The experimental results depicted that corrosion inhibition efficiency increases with addition of inhibitor content and it adversely decreases as a function of temperature. Particularly, the highest inhibition efficiencies of ~66.8 %and ~52% were achieved for the extracts of BFDME and BFDWE, respectively, for inhibitor concentration of 0.4 g/l. Further, adsorption of molecules, presence in BFDME and BFDWE, on active sites of aluminum surface was of physisorption and it obeyed Langmuir adsorption isotherm. Potentiodynamic polarization results showed that BFDME and BFDWE perform as mixed-type inhibitors with notable cathodic nature. The surface morphological study by scanning electron microscope (SEM) further confirmed the existence of passive layers of BFDME and BFDWE molecules on top of aluminum's surface and thus promotes anti-corrosion.

The corrosion inhibition of aluminium in 1 M H2SO4 using expired drugs of moxifloxacin and betnesol as corrosion inhibitors has studied by weight loss measurements, potentiodynamic polarization studies, electrochemical impedance spectroscopy and scanning electron microscope analysis. The experimental studies show that drugs thus used inhibitors reduce the corrosion of aluminium and the inhibition efficiency increases with addition of moxifloxacin and betnesol at various temperatures. Moreover, potentiodynamic polarization curves illustrate that both betnesol and moxifloxacin act as mixed type inhibitors but predominantly anodic process of corrosion. In addition, EIS studies show that transfer resistance increases with the addition of inhibitor concentration. The effect of temperature on aluminium corrosion upon with and without the presence of inhibitors was also investigated in detail. Thermodynamic and adsorption isotherm calculations reveal that the used drug molecules have both chemisorption and physisorption with aluminium metal and followed the Langmuir adsorption isotherm.

The inhibition efficiency and mechanism of agarose on aluminium corrosion in 1 M HCl, 0.5 M H2SO4 and 0.5 M H3PO4 solutions were studied by means of conventional weight loss method, Tafel polarisation electrochemical impedance spectroscopy and scanning electron microscope. The inhibition efficiency (%IE) was observed to increase with addition of agarose concentration, and it adversely decreases with increasing temperature. Moreover, the maximum inhibition efficiency of ~81% is achieved for agarose concentration of 700 ppm in 1 M HCl. Potentiodynamic polarisation curves showed that agarose acts as a mixed-type inhibitor. The absorption isotherm calculations revealed that interactions of agarose on aluminium surface are physisorption and typically obey the Temkin adsorption isotherm. The quantum chemical calculations reveal that active sites promote the agarose to anchor on aluminium surface due to mostly presence of hydroxyl group.

Donor–acceptor alternated conjugated copolymers based on benzotriazole acceptor units and electron-donating units such as fluorene, carbazole and silyl fluorene, were synthesized through palladium catalyzed Suzuki cross-coupling polymerization. NMR and elemental analyses were achieved to confirm the structure of each copolymer. Their thermal, photophysical and electrochemical properties are also reported. The photovoltaic characteristics of these polymers determined from bulk-heterojunction photovoltaic cells are discussed.

International audience; The synthesis and X-ray crystal structure of the ligand L (4,7-dicarbazol-9-yl-[1,10]-phenanthroline) are reported, as well as those of the molecular complex, [Eu(tta)3(L)] (1), (tta = 2-thenoyl trifluoroacetylacetonate). Their photophysical properties have been investigated both in solution and in the solid state. It was shown that the ligands used for designing 1 are well-suited for sensitizing the EuIII ion emission, thanks to a favorable position of the triplet state as investigated in the GdIII complex [Gd(tta)3(L)], (2). The low local symmetry of the EuIII ion shown by the X-ray crystal structure of 1 is also revealed by luminescence spectroscopy. Because of interesting volatility and solubility properties, 1 is shown to behave as a real molecular material that can be processed both by thermal evaporation and from solution. When doped in poly(methylmethacrylate) (PMMA), 1 forms air-stable and highly red-emitting plastic materials that can be excited in a wide range of wavelengths from the UV to the visible part of the electromagnetic spectrum (250-560 nm). Absolute quantum yields of 80% have been obtained for films comprising 1-3% of 1. Ellipsometry measurements have been introduced to gain information on physical data of 1. They have been performed on thin films of 1 deposited by thermal evaporation and gave access to the refractive index, n, and the absorption coefficient, k, as a function of the wavelength. A value of 1.70 has been found for n at 633 nm. These thin films also show interesting air-stability.

Poly(amido amine) (PAMAM, generation 2), a solution-processable dendrimer, is used as the electron-collection interlayer on indium tin oxide (ITO) for inverted polymer solar cells (PSCs) with poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester as the active materials. The inverted PSCs exhibited a power conversion efficiency of 3.53% under AM1.5G illumination, which is significantly higher than that of the control inverted PSCs with blank ITO and comparable to that of the control PSCs with normal architecture. The high-performance of the inverted PSCs is attributed to the reduction of the work function of ITO by 0.75 eV by PAMAM.

We report highly efficient polymer solar cells (PSCs) with rhodamine 101, a conjugated zwitterion with positive and negative charges on the same molecule, as the electron-collection interlayer. Rhodamine 101 can be processed by solution processing techniques or thermal deposition. The rhodamine 101 interlayer simultaneously improves the short-circuit current, open-circuit voltage, fill factor so as to improve the photovoltaic efficiency of the PSCs with poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl] (PCDTBT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the active materials in comparison with control PSCs with Al or Ca/Al as the cathode. The photovoltaic efficiency reaches 6.15% for the PSCs with rhodamine 101/Al as the cathode under AM1.5G illumination, whereas the efficiencies are only 3.81% and 4.57% for the control PSCs with Al and Ca/Al as the cathodes, respectively. On the other hand, the improvement on the photovoltaic performance by the rhodamine 101 interlayer is less remarkable for the PSCs with poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) or PC71BM as the active materials. The photovoltaic efficiency is 4.25% for the PSCs with rhodamine 101/Al as the cathode, almost the same as that (4.20%) of the control PSCs with Ca/Al as the cathode. The high efficiency of the PSCs with the rhodamine 101 interlayer is ascribed to the lowering of the work function of metals by rhodamine 101 that has a strong dipole moment. The different effects of the rhodamine 101 interlayer on the two PSCs with PCDTBT and P3HT as the donor materials are attributed to different reactivities of the two polymers with active metals like Ca and Al. PCDTBT consisting of both electron-donating and electron-withdrawing units is more reactive with the active metals. The reaction between PCDTBT and Ca leads to low photovoltaic efficiency of the PSCs with Ca/Al as the cathode.