Alkoxy Research Articles

Impact of alkyl chains, electron donor substituents and acidic group on aggregation-induced emission of carboxylic acid functionalized quinoxalines

We report an optical study of quinoxaline-based luminogens derived from 2,3-bis(aryl)-quinoxaline-6-carboxylic acid (1a, 1b, and 2) in solution and solid state. These compounds were fluorescent in solid films and in solutions with emission bands ranging from blue to green (445–517 nm). They showed a positive solvatochromism in the PL spectra, indicative of intramolecular charge transfer (ICT) in the excited state. 1a, 1b, and 2 exhibited Aggregation-Induced Enhanced Emission (AIEE) characteristics with a drastic change in properties by increasing alkyl chains and donor alkoxy groups. Their carboxylate potassium salts had a blueshift emission compared to the acid carboxylic form and a significant quenching in PL intensity in protic polar solvents. The salt of 1a presented an Aggregation-Induced Emission (AIE) profile, its weak fluorescence in water had an expressive enhancement by adding THF. Theoretical calculations were also carried out considering implicit solvent effects. The optimized structures of compounds and their simulated UV–vis absorption spectra showed no significant differences in water and acetonitrile. These results are in good agreement with the solvatochromism experiments. The calculated HOMO-LUMO energy gaps were 3.47 eV in both solvents, and the energy levels for HOMO and LUMO are slightly lower in water.

Dual-functionalized amines as single-component water-lean CO2 absorbents with low-viscosity and high-capacity: The synergistic effect of alkoxy and silyl groups

Water-lean CO2 absorbents are promising alternatives to conventional aqueous alkanolamine-based solvents due to the potential benefits of reduced energy input and improved capacity. However, the exponential increase in viscosity with CO2 loading prohibits their industrial deployment by weakening internal mass and heat transfer as well as deteriorating or even blocking pipeline transportation. In this work, a series of alkoxy-silyl dual-functionalized amines have been devised as single-component CO2 absorbents in order to achieve enhanced flowability and efficiency under water-lean conditions. These nonaqueous amines were proved to be highly flowable (8–27 cP at 25 °C, 3–9 cP at 40 °C) under their maximum gravimetric capacity (11–17 wt% at 25 °C, 9–14 wt% at 40 °C), which is comparable to fully loaded 30 wt% MEA (11 cP at 25 °C, 4 cP at 40 °C). The synergistic effect of alkoxy and silyl groups on viscosity and capacity was systematically investigated by means of 13C NMR, in situ FTIR, DSC, VLE and DFT calculation, indicating that the reversible formation of carbamic acid through dual-stabilization, i.e. alkoxy-proton hydrogen bonding and silyl-oxygen complexation, should play the key role in improving both flowability and reaction stoichiometry. Meanwhile, these novel absorbents could be easily regenerated by desorption at 70 °C, and they could maintain structural integrity for at least 2 days under aerobic heating at 80 °C within closed system under CO2-loaded state. Furthermore, the intrinsic CO2-philic nature of both alkoxy and silyl functionalities would offer significant physical absorption under high pressures (20 and 30 bar). Hence, with remarkable flowability, enhanced capacity and easy reversibility, such dual-functionalized amines should certainly represent competitive candidates for further scale up and practical application.

Environmentally Friendly Synthesis and Self‐Catalytic Hydrolysis of Triazole‐Modified Organosilanes for Polysiloxane Production

AbstractOrganotrialkoxysilanes are unique compounds that play an important role in modern science and industry. Their structure determines their varied use both in production and academic research. The development of the synthesis of organotrialkoxysilanes and polymers based on them, taking into account environmental realities, is an important task. In our work, we present an original approach for the preparation of organotriethoxysilanes, starting from azidoalkyltriethoxysilanes and various types of substrates containing a terminal triple bond, by the azide‐alkyne cycloaddition (CuAAC) mechanism without the use of solvents, catalyst ligands, and amines. We also found the self‐catalyzing effect of the triazole fragment resulting from the azide‐alkyne cycloaddition in the reaction of hydrolysis and condensation of alkoxy groups, which made it possible to obtain a series of silsesquioxane products only by adding water, without the use of catalysts. As a result, a new, original scheme for the preparation of organosilicon organotrialkoxysilanes of a monomeric structure with their subsequent transformation into silsesquioxane polymers under “green” conditions is built.

Electron ionization fragmentation studies for a series of 4-methoxymethylene benzoate esters.

Product ion studies and stable isotope deuterium labeling experiments provide useful data for understanding the electron ionization (EI)-mass spectroscopy (MS) fragmentation of methoxymethylene substituted benzoate esters. The methoxymethylene ether is regioisomeric with the ethoxy group and represents the two possible ether substituents of a benzene ring of C2 H5 O. Structural confirmation of these synthetic precursor materials via gas chromatography (GC)-EI-MS revealed unexpected fragment ions. The synthesis and EI-MS evaluation of some homologs and deuterated derivatives allowed for the characterization of these unique ions and their fragmentation pathways. The relative effects of the position of the oxygen of the ether side chain are the subject of this investigation. The desired compounds were prepared from 4-chloromethylbenzoyl chloride by alkoxide displacement followed by transesterifications and the deuterated analogs were prepared similarly. The compounds were separated by capillary GC and their MS fragmentation evaluated in EI, MS/MS and chemical ionization experiments. The methoxymethylene-substituted benzoate esters yield major fragment ions from the loss of the alkyl group from the ether as well as alkoxy group loss from the ester or ether portion of the molecule. The loss of the alkyl group from the ether followed by loss of the ester alkoxy group as the corresponding alcohol yielded the unique cation at m/z 133 for all compounds. The identity of the major ions was confirmed by product ion and deuterium labeling studies and possible mechanisms of fragment ion formation are described. The aliphatic oxygen of the alkoxymethylene group plays a much more active role in the EI-MS fragment formation profile than the direct aromatic ring linked oxygen of the ethoxy group. Thus, yielding a greater variety of characteristic fragments. The m/z 133 ion is unique to this class of compounds and does not have an equivalent pathway for the regioisomeric ethoxy series.

Configurationally Nonselective Aquation of a Mononuclear Ru(II) Chloro Complex to Aquo Complex Isomers with Distinctive Aspects in Photoisomerization, Redox, and Catalytic Water Oxidation.

distal-[Ru(EtOtpy)(pynp)Cl]+ (d-EtO1Cl) (EtOtpy = 4'-ethoxy-2,2':6',2″-terpyridine, pynp = 2-(2-pyridyl)-1,8-naphthyridine), and distal/proximal-[Ru(EtOtpy)(pynp)OH2]2+ (d/p-EtO1H2O) complexes were newly synthesized to investigate the synergistic influence of the geometric configuration coupled with substituent introduction of an ethoxy (EtO) group on the physicochemical properties and reactions of the Ru(II) complexes. Configurationally nonselective aquation of d-EtO1Cl was uniquely observed to form d/p-EtO1H2O isomers in water, in contrast to configurationally selective aquation of distal-[Ru(tpy)(pynp)Cl]+ (d-1Cl, tpy = 2,2':6',2″-terpyridine) without the EtO group [Yamazaki, H. . J. Am. Chem. Soc. 2011, 133, 8846-8849].The kinetic profiles of the aquation reactions of d-EtO1Cl were well analyzed using a sequential reversible reaction model assuming the reversible interconversion between d/p-EtO1H2O isomers via d-EtO1Cl. The observed equilibrium constant (Kiso) of isomerization between p/d-EtO1H2O was calculated from the kinetic analysis as Kiso = 0.45, which is consistent with the final concentration ratio (1:0.43) of p/d-EtO1H2O generated in the aquation reaction of d-EtO1Cl. The irreversible photoisomerization from d-EtO1H2O to p-EtO1H2O was observed in water with an internal quantum yield (Φ) of 0.44% at 520 nm. Electrochemical measurements showed that d-EtO1H2O undergoes a 2-step oxidation reaction of 1H+-coupled 1e- processes of RuII-OH2/RuIII-OH and RuIII-OH/RuIV═O at pH 1.3-9.7, whereas p-EtO1H2O undergoes a 1-step oxidation reaction of a 2H+-coupled 2e- process of RuII-OH2/RuIV═O in the pH range of 1.8-11.5. Any redox potential of d/p-EtO1H2O isomers was decreased by the electro-donating EtO substitution, compared with distal/proximal-[Ru(tpy)(pynp)OH2]2+ (d/p-1H2O). The turnover frequency (kO2 = 1.7 × 10-2 s-1) of d-EtO1H2O for water oxidation catalysis is higher than that (3.5 × 10-4 s-1) of p-EtO1H2O by a factor of 48.6. The kO2 value (1.7 × 10-2 s-1) for d-EtO1H2O is 4.5-fold higher than those of d-1H2O (3.8 × 10-3 s-1). The higher kO2 value of d-EtO1H2O compared with d-1H2O could be explained by the fast oxidation rate from RuIV═O to RuV═O involved in the rate-determining step due to the electron-donating EtO group.

Alkoxy substitution on simple non‐fused electron acceptors for tuning the photoelectric properties of organic solar cells

AbstractIn order to identify high‐performance non‐fused ring electron acceptors for bulk heterojunction (BHJ) solar cells, six structurally diverse molecules are designed and categorized into two series. The first series is anchored by R1 as the reference molecule, featured fixed BDT, IC‐2F end groups and modified π bridges. The second series is anchored by R2 as the reference molecule, incorporated a terminal IC‐2F and a central core modified with EDOT bridge. The electronic structure and photoelectric properties of all acceptor molecules were investigated using density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT). Charge transfer matrix (CTM), Density of states (DOS) and Reorganization energy (RE) etc. were analyzed to provide fundamental knowledge on charge transport and electronic excitation. Among the studied molecules, W2 exhibited a smaller energy gap (1.74 eV) compared to the other molecules, effectively transferring its electron from HOMO to LUMO. At the same time, the W2 molecule has excellent Voc and FF. Furthermore, W2 displayed the largest λmax redshift compared to R1. Although W3 had a smaller value of λh, the comprehensive photovoltaic parameters of W2 were more excellent. The research results not only demonstrated the feasibility of introducing different alkoxy groups to alter the structure of the π bridge and central core is a feasible method for constructing high‐performance NFREAs, but also highlighted that BDT cores combined with EDOT bridges are among the most promising small molecule acceptors (SMAs) that could be considered as reasonable candidates for synthesis and incorporation into organic solar cells. The results of this study are expected to provide seminal ideas for the design of high‐performance non‐fullerene acceptors.

Introducing alkoxy groups as outer side chains and substituents of π-bridges obtains high-performance medium-bandgap polymerized small molecule acceptors

Introducing alkoxy groups as outer side chains and substituents of π-bridges obtains high-performance medium-bandgap polymerized small molecule acceptors

Features of Nitration of Aromatic Aldehydes with the Difluoromethoxy Group

Nitration of aromatic aldehydes with difluoromethoxy group results in the partial ipso-substitution of the aldehyde group if difluoromethoxy group is located in the para-position to the aldehyde group. The presence of a chlorine atom in the meta-position to the aldehyde group increases the contribution of the ipso-substitution, while the presence of a chlorine atom in the ortho-position to the aldehyde group reduces it. The presence of strong donors (alkoxy groups) in the molecule eliminates the contribution of the ipso-substitution.

Production of Reduced Graphene Oxide by Using Three Different Microorganisms and Investigation of Their Cell Interactions.

Despite the huge and efficient functionalities of reduced graphene oxide (RGO) for bioengineering applications, the use of harsh chemicals and unfavorable techniques in their production remains a major challenge. Microbial production of reduced graphene oxide (RGO) using specific bacterial strains has gained interest as a sustainable and efficient method. The reduction of GO to RGO by selected bacterial strains was achieved through their enzymatic activities and resulted in the removal of oxygen functional groups from GO, leading to the formation of RGO with enhanced structural integrity. The use of microorganisms offers a sustainable approach, utilizing renewable carbon sources and mild reaction conditions. This study investigates the production of RGO using three different bacterial strains: Lactococcus lactis (L. Lactis), Lactobacillus plantarum (L. plantarum), and Escherichia coli (E. coli) and evaluates its toxicity for safe utilization. The aim is to assess the quality of the produced RGO and evaluate its toxicity for potential applications. Thus, this study focused on the microbial production of reduced graphene oxides well as the investigation of their cellular interactions. Graphite-derived graphene oxide was used as a starting material and microbially reduced GO products were characterized using the FTIR, Raman, XRD, TGA, and XPS methods to determine their physical and chemical properties. FTIR shows that the epoxy and some of the alkoxy and carboxyl functional groups were reduced by E. coli and L. lactis, whereas the alkoxy groups were mostly reduced by L. plantarum. The ID/IG ratio from Raman spectra was found as 2.41 for GO. A substantial decrease in the ratio as well as defects was observed as 1.26, 1.35, and 1.46 for ERGO, LLRGO, and LPRGO after microbial reduction. The XRD analysis also showed a significant reduction in the interlayer spacing of the GO from 0.89 to 0.34 nm for all the reduced graphene oxides. TGA results showed that reduction of GO with L. lactis provided more reduction than other bacteria and formed a structure closer to graphene. Similarly, analysis with XPS showed that L lactis provides the most effective reduction with a C/O ratio of 3.70. In the XPS results obtained with all bacteria, it was observed that the C/O ratio increased because of the microbial reduction. Toxicity evaluations were performed to assess the biocompatibility and safety of the produced RGO. Cell viability assays were conducted using DLD-1 and CHO cell lines to determine the potential cytotoxic effects of RGO produced by each bacterial strain. Additionally, apoptotic, and necrotic responses were examined to understand the cellular mechanisms affected by RGO exposure. The results indicated that all the RGOs have concentration-dependent cytotoxicity. A significant amount of cell viability of DLD-1 cells was observed for L. lactis reduced graphene oxide. However, the highest cell viability of CHO cells was observed for L. plantarum reduced graphene oxide. All reduced graphene oxides have low apoptotic and necrotic responses in both cell lines. These findings highlight the importance of considering the specific bacterial strain used in RGO production as it can influence the toxicity and cellular response of the resulting RGO. The toxicity and cellular response to the final RGO can be affected by the particular bacterial strain that is employed to produce it. This information will help to ensure that RGO is used safely in a variety of applications, including tissue engineering, drug delivery systems, and biosensors, where comprehension of its toxicity profile is essential.

Structural tailoring of p-terphenyl scaffold: Towards advanced plastic scintillator

A comprehensive series of fifteen p-terphenyl derivatives has been designed and prepared using facile synthetic approaches (Suzuki-Miyaura and Friedel-Crafts reactions). Various alkyl, alkoxy or trifluoromethyl groups have been attached to p-terphenyl to gain both symmetrical and unsymmetrical derivatives. Symmetry breaking accounts for improved solubility of mono-substituted derivatives. Thermal analysis revealed a reversible formation of several crystalline phases and very high thermal robustness. Reduction and oxidation of the parent p-terphenyl π-system affected by the electronic and steric effects of the substituents were recorded by cyclic voltammetry. When compared to parent p-terphenyl, a narrowed HOMO–LUMO gap has been measured/calculated for most of the prepared derivatives. The absorption and emission maxima ranged from 286 to 293 and 341–360 nm, respectively. The latter is affected by the substitution more significantly, the fluorescence quantum yields are within the range of 0.52–0.75. Stokes shifts up to 6400 cm−1 were measured pointing to a large structural rearrangement (planarization) upon excitation. PTP derivatives were further used as primary and secondary luminophores for scintillation. 4-Methyl-p-terphenyl proved to be a superior luminophore with a straightforward synthesis, easy isolation, large solubility and excellent luminescence characteristic. Based on this derivative, a plastic scintillator has been manufactured that showed superior performance as compared to standard and widely used unsubstituted p-terphenyl. Thus, a relatively minor structural change (appending single methyl group) altered scintillation properties significantly.

Highly Electrophilic Mononuclear Cationic Aluminum Alkoxide Complexes: Syntheses, Reactivity and Catalytic Applications.

Herein, we report on the synthesis of β-diketiminate supported aluminum complexes bearing terminal alkoxide and mono-thiol functional groups: LAlOMe(Et) (2), LAlOtBu(Et) (3), and LAlSH(Et) (4), (L= [HC{C(Me)N-(2,6-iPr2C6H3)}2]). Complexes 2 and 3 are further utilized as synthons to generate some fascinating cationic aluminum alkoxide complexes, [LAlOMe(µ-OMe)-Al(Et)L][EtB(C6F5)3] (5), [LAlOMe(OEt2)][EtB(C6F5)3] (6), and [LAlOtBu(OEt2)][EtB(C6F5)3] (8). These electrophilic cationic species are well characterized by spectroscopic and crystallographic techniques. The assessment of Lewis acidity by the Gutmann-Beckett method revealed superior Lewis acidity of the cations substituted with electron demanding alkoxy groups in comparison to the known methyl analogue [LAlMe][B(C6F5)4]. This has been further endorsed by computational calculations to determine the NBO charges and hydride ion affinity for complexes 6 and 8. These complexes are also capable of activating triethylsilane in stoichiometric reactions. The applicability of these complexes has been realized in the hydrosilylation of ethers, carbonyls, and olefines. Additionally, the solid state structure of a new THF stabilized aluminum halide cation [LAlCl(THF)][B(C6F5)4] (11) has also been reported.

Mycobacterium tuberculosis Inhibitors Based on Arylated Quinoline Carboxylic Acid Backbones with Anti-Mtb Gyrase Activity.

New antitubercular agents with either a novel mode of action or novel mode of inhibition are urgently needed to overcome the threat of drug-resistant tuberculosis (TB). The present study profiles new arylated quinoline carboxylic acids (QCAs) having activity against replicating and non-replicating Mycobacterium tuberculosis (Mtb), the causative agent of TB. Thus, the synthesis, characterization, and in vitro screening (MABA and LORA) of 48 QCAs modified with alkyl, aryl, alkoxy, halogens, and nitro groups in the quinoline ring led to the discovery of two QCA derivatives, 7i and 7m, adorned with C-2 2-(naphthalen-2-yl)/C-6 1-butyl and C-2 22-(phenanthren-3-yl)/C-6 isopropyl, respectively, as the best Mtb inhibitors. DNA gyrase inhibition was shown to be exhibited by both, with QCA 7m illustrating better activity up to a 1 μM test concentration. Finally, a docking model for both compounds with Mtb DNA gyrase was developed, and it showed a good correlation with in vitro results.

Oligomers based on cyanoacrylic acid esters

Ethyl 3-alkoxy-2-cyanopropanoates were prepared by the reaction of ethyl 2-cyanoacrylate with the corresponding linear alkanols C6–C12 in acidic medium. Their treatment with water as a weak nucleophile resulted in elimination of the alkanol and the formation of oligocyanoacrylate terminated with the alkoxy group. The oligomers were studied by NMR spectroscopy, IR spectroscopy, MALDI-TOF mass-spectrometry and dynamic light scattering.

New task-specific ionic liquids as bifunctional organocatalysts; Synthesis, characterization, and computational insights

A new class of functionalized imidazolium-based Task-Specific Ionic Liquids (TSILs) is designed as low-cost bifunctional organocatalyst. New alkoxymethylimidazolium ILs are efficiently synthesized under solvent free conditions and extensively characterized by physical and spectral studies. The newly synthesized ILs demonstrate excellent catalytic potential in condensation reactions of high importance, such as the Biginelli reaction for the synthesis of medicinally important dihydropyrimidiones. The effect of the alkoxy group and counter-ions in the imidazolium salts were evaluated in detail. Moreover, computational studies were employed to explore the structural dynamics and physicochemical properties of the prepared ionic liquids. 3-(iso-butoxymethyl)-1-methyl-1H-imidazol-3-ium tetrafluoroborate (iBOMMIMBF47) exhibited the highest catalytic ability due to the combined influence of the alkoxy group structure, counterion nature, high electrophilicity index, and availability of the reactive C2-H. Some notable advantages of the new TSILs include efficient catalyst preparation, simple work-up procedure, recyclability, short reaction times, and excellent yields.

Simultaneous determination of five indole/indazole amide-based synthetic cannabinoids in electronic cigarette oil by ultra performance liquid chromatography

Synthetic cannabinoids (SCs), which are considered some of the most widely abused new psychoactive substances available today, are much more potent than natural cannabis and display greater efficacy. New SCs can be developed by adding substituents such as halogen, alkyl, or alkoxy groups to one of the aromatic ring systems, or by changing the length of the alkyl chain. Following the emergence of the so-called first-generation SCs, further developments have led to eighth-generation indole/indazole amide-based SCs. Given that all SCs were listed as controlled substances on July 1, 2021, the technologies used to detect these substances must be quickly improved. Due to the sheer number of SCs, the chemical diversity and the fast update speed, it is challenging to determine and identify the new SCs. In recent years, several types of indole/indazole amide-based SCs have been seized, but systematic research on these compounds remains limited. Therefore, developing rapid, sensitive, and accurate quantitative methods to determine new SCs are of great importance. Compared with high performance liquid chromatography (HPLC), ultra performance liquid chromatography (UPLC) shows higher resolution, better separation efficiency, and faster analysis speeds; thus, it can meet the demand for the quantitative analysis of indole/indazole amide-based SCs in seized materials. In this study, a UPLC method was developed for the simultaneous determination of five indole/indazole amide-based SCs, including N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-butyl-1H-indazole-3-carboxamide (ADB-BUTINACA), methyl 2-(1-(4-fluorobutyl)-1H-indole-3-carboxamido)-3,3-dimethylbutanoate (4F-MDMB-BUTICA), N-(1-methoxy-3,3-dimethyl-1-oxobutan-2-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide (5F-MDMB-PICA), methyl 3,3-dimethyl-2-(1-(pent-4-en-1-yl)-1H-indazole-3-carboxamido)butanoate (MDMB-4en-PINACA), and N-(adamantan-1-yl)-1-(4-fluorobutyl)-1H-indazole-3-carboxamide (4F-ABUTINACA) in electronic cigarette oil; these SCs have been detected with increasing frequency in seized materials in recent years. The main factors influencing the separation and detection performance of the proposed method, including the mobile phase, elution gradient, column temperature, and detection wavelength, were optimized. The proposed method successfully quantified the five SCs in electronic cigarette oil via the external standard method. The samples were extracted using methanol, and the target analytes were separated on a Waters ACQUITY UPLC CSH C18 column (100 mm×2.1 mm, 1.7 μm) at column temperature of 35 ℃ and flow rate of 0.3 mL/min. The injection volume was 1 μL. The mobile phase consisted of acetonitrile and ultrapure water, and gradient elution was employed. The detection wavelengths were 290 and 302 nm. The five SCs were completely separated within 10 min under optimized conditions and showed good linear relationships between 1-100 mg/L, with correlation coefficients (r2) of up to 0.9999. The limits of detection (LOD) and quantification (LOQ) were 0.2 and 0.6 mg/L, respectively. Precision was determined using standard solutions of the five SCs at mass concentrations of 1, 10, and 100 mg/L. The intra-day precision (n=6) was <1.5%, and the inter-day precision (n=6) was <2.2%. Accuracy was determined by spiking electronic cigarette oil with low (2 mg/L), moderate (10 mg/L), and high (50 mg/L) levels of the five SCs, with six replicates per determination. The recoveries of the five SCs were 95.5%-101.9%, and their relative standard deviations (RSDs, n=6) were 0.2%-1.5%, with accuracies ranging from -4.5% to 1.9%. The proposed method showed good performance when applied to the analysis of real samples. It is accurate, rapid, sensitive, and effective for the determination of five indole/indazole amide-based SCs in electronic cigarette oil. Thus, it satisfies the requirements for practical determination and provides a reference for the determination of SCs with similar structures by UPLC.

Alkoxymigration onto α‐Imino Gold Carbenes for Constructing Propellane‐Type Indolines

AbstractWe developed a new reaction entity of α‐imino gold carbenes involving alkoxy migration. The reaction would proceed through oxonium ylide formation by intramolecular addition of an alkoxy group, carbon‐oxygen bond cleavage, and carbon−carbon bond formation. We achieved an efficient gold‐catalyzed synthesis of indoline‐propellanes via a one‐pot sequence by using ethylene glycol as a trapping reagent.

Study on the self-assembly performance of a perylene derivative

Perylene diimide (PBI) had high thermal stability and solubility, so it could be used as a practical new type material of energy saving and environmental protection. The solubilization and photoelectrical properties of the bays can be effectively improved by introducing substituents in the bays. On the other hand, the imide group has a strong ability to absorb electrons, and the alkoxy group after the bay site substitution makes it easy to form micro-nano fiber in good and bad solvents. In other words, most of the properties of PBI derivatives are related to their ability to form micro-nano fiber. A systematic study of N, N' -isoctyl-1, 7-bis (octanoxy) perylene diimide (DFPBI) was carried out by UV-VIS spectrophotometry, thermogravimetry and fluorescence spectrophotometry. A number of test results show that DFPBI has better solubility and thermal stability than PBI, and can grow micro-nano fiber in both good and bad solvent systems. Therefore, DFPBI has broad application prospects in sensors.

Physical and Thermal Characterizations of Newly Synthesized Liquid Crystals Based on Benzotrifluoride Moiety.

The mesomorphic stability and optical activity of new group-based benzotrifluoride liquid crystals, (E)-4-(((4-(trifluoromethyl) phenyl) imino) methyl) phenyl 4-(alkyloxy)benzoate, or In, were investigated. The end of the molecules connected to the benzotrifluoride moiety and the end of the phenylazo benzoate moiety have terminal alkoxy groups which can range in chain length from 6 to 12 carbons. The synthesized compounds' molecular structures were verified using FT-IR, 1H NMR, mass spectroscopy, and elemental analysis. Mesomorphic characteristics were verified using differential scanning calorimetry (DSC) and a polarized optical microscope (POM). All of the homologous series that have been developed display great thermal stability across a broad temperature range. Density functional theory (DFT) determined the examined compounds' geometrical and thermal properties. The findings showed that every compound is entirely planar. Additionally, by using the DFT approach, it was possible to link the experimentally found values of the investigated compounds' investigated compounds' mesophase thermal stability, mesophase temperature ranges, and mesophase type to the predicted quantum chemical parameters.

Studies of various properties of different derivatives of asymmetric poly(paraphenylenevinylene) (PPV) polymers for light emitting applications

In this study various poly(paraphenylenevinylene) (PPV) derivatives with different asymmetric alkoxy side-chain lengths were synthesized by a modified Gilch polymerization to improve solubilities and to investigate photoluminescence for light-emitting performance. The optical properties of the monomers and polymers with different alkoxy groups, bonded to the PPV main chain, were examined by UV–Vis and photoluminescence spectroscopy. The UV–Vis spectra showed increases in the intensities of the π-π* transition peaks of asymmetric PPV polymers compared to those of the asymmetric monomers. The excitation and emission wavelengths in the solution states were 467–472 nm and 571–579 nm, respectively. The photoluminescence quantum efficiencies of asymmetric polymers were also investigated and found as being 31–38%, with long excited-state lifetimes of 2.94–3.53 ns. The photoluminescence quantum efficiencies of the asymmetric monomers and polymers were compared. The band gap energy value with respect to emission energies were calculated to be in the range 2.17–2.13 eV for the asymmetric polymers. It was noted that these polymers demonstrated good thermal stabilities and optical and photoluminescence properties, showing great potential in optoelectronic applications. The thermal properties and heat changes in the polymer structures were studied by TGA and DSC. All polymers were amorphous, being stable up to 380 °C. The pre-decay temperature for asymmetric dialkyl monomers was around 169 °C and around 380 °C for the asymmetric dialkyl polymers. Most of the mass losses for asymmetric dialkyl monomers occurred in the range 185–475 °C and 396–512 °C for asymmetric dialkyl polymers. The DSC graphs of these polymers revealed the glass transition temperatures (Tg) 76–113 °C. Thus the PPV derivatives having longer flexible alkyl or alkoxy substituents revealed low Tg or low morphological stabilities. The asymmetric dialkyl PPV polymers showed enthalpies 58.79–123.15 cal/g and entropies 0.176–0.343 cal/g oC.

Conversion of carbonaceous materials into solid acids for tylosin mitigation: effect of preprocessing methods on the reactivity of sulfonation reaction

Carbon-based solid acids have been successfully employed as acidic catalysts for pollutant mitigation in wastewater. To fully tap the potentials of commercially viable carbons for the preparation of solid acids and enhance their catalytic performances is a challenging problem. In this work, three commercialized carbons including biochar, activated carbon and graphite were preprocessed (ball-milling, Hummer exfoliation, HNO3 soaking, and microwave heating in HNO3, etc.), sulfonated, and evaluated as solid-acid catalysts for tylosin mitigation. Graphite-originated solid acid performed the best through a balling-milling preprocess, while biochar-originated solid acids behaved well under all preprocessing treatments, in which 40 mg L−1 of tylosin was mitigated within 8 min by 1 g L−1 of biochar-originated solid acids. The biochar solid acid through the ball-milling preprocess presented high total acidity and large amounts of –SO3H groups, due to dramatically increased surface area and the rise of activation groups (hydroxyl, alkyl and alkoxy groups, etc.) facilitating electrophilic reaction. In addition, decreased particle size and aromaticity and increased structural defects also contributed. Theoretical calculation of average local ionization energy (ALIE) of condensed aromatic model molecules with substituted activation groups confirmed the promoting effects on sulfonation from strong to weak were 8.40–9.06 eV. These findings have deepened the knowledge in tuning carbon surface chemistry for better sulfonation, thus strengthening catalytic degradation of tylosin. The value of this study is in pulling a clear thread for maneuvering solid-acid catalysts using carbons, which holds a novel promise for rationally functionalizing biochar-based catalysts for the remediation of macrolide antibiotics in polluted water.Graphical