Phenyl Functional Groups Research Articles

Effect of Phenyl Functional Groups on the Stability of Dodecyl Sulfonate Emulsified Asphalt

Effect of Phenyl Functional Groups on the Stability of Dodecyl Sulfonate Emulsified Asphalt

Effect of phenyl functional groups on the adsorption behaviour of dodecyl anionic emulsifiers on oxides on the aggregate surface

ABSTRACT Emulsified asphalt finds extensive application in pavement repair, addressing issues like road ruts and cracks. While the adsorption behaviour of emulsifiers on oxide surfaces (CaCO3 and SiO2) of aggregates is influenced by the presence of phenyl functional groups, the precise mechanism of this influence remains insufficiently understood. This study employs molecular dynamics models and macroscopic experiments to investigate the mechanism involving emulsifiers, sodium ions, and water at aggregate interfaces, quantifying the role of phenyl functional groups from a molecular perspective. The results reveal the following: strong electrostatic attraction between alkaline aggregates and Na+, leading to substantial Na+ adsorption. The phenyl functional groups reduce diffusion coefficient, adsorption energy, and amounts in alkaline aggregates (−34.6%, −16%, −12.5%), while increasing them in acidic aggregates (+15.9%, + 14.7%, + 27.7%). The phenyl functional groups impact hydrogen bond acceptors, TPSA, and emulsifier complexity, altering adsorption. They enhance emulsifier electrostatic potential, affecting adsorption on different surfaces. In summary, this ongoing research framework aims to fine-tune emulsifiers through the use of phenyl functional groups, enhancing adsorption strength, adsorption amount, and diffusion between emulsifiers and aggregates. This work holds great significance for optimizing emulsifier molecular structures.

Electrophilic substitution reactivity prediction of crown ether derivatives

AbstractLithium is important for the world's economic development because it is the primary component of batteries. Crown ether derivatives are widely used for the separation and enrichment of lithium. The conformations of the designed crown ether were studied using molecular dynamics simulation. The electrophilic substitution reactivities of different conformations were analyzed by the conceptual density functional theory (CDFT) and the frontier molecular orbital theory (FMO). The analysis results show that the reactivity of the phenyl group can be increased by the π–π conjugation effect and bonded oxygen atoms. According to the reduced density gradient (RDG), the van der Waals interactions between the phenyl functional groups and methyl groups also benefit the reactivity. According to the global softness and nucleophilicity index, the reactivity of is the highest. The condensed Fukui function, condensed local nucleophilicity index, and condensed local softness show that the electrophilic substitution reactivity of is the highest. also has the largest HOMO orbital composition. The analysis results of CDFT and FMO are consistent with each other, which suggests that the Koopmans approximation is suitable for the reactivity analysis of crown ether derivatives.

Effect of phenyl functional group on the demulsification process of dodecyl anion emulsified asphalt

The demulsification of emulsified asphalt is required to form the adhesion of the asphalt. Using conductivity experiments and validated molecular dynamics simulations, this paper investigated the micro-mechanism of the demulsification process of emulsified asphalt. The results show that the phenyl functional group causes a decrease in the diffusion coefficient of the SiO2 aggregate system and an increase in its interfacial energy, whereas an inverse tendency occurs in the CaCO3 aggregate system, which significantly affects the demulsification rate and adhesion between the emulsified asphalt and aggregates. The electrostatic force between Na+ and CaCO3 allows the emulsifiers to adsorb well to the aggregates, and the demulsification time can be controlled by adjusting the relative content of phenyl functional groups and Na+. The adsorption rate and the adsorption amount of dodecyl anion emulsified asphalt on the aggregate surface grow with increasing phenyl functional group content, leading to a faster demulsification rate of the system and enabling the demulsification rate of the SiO2 emulsified asphalt system to be greater than that of the CaCO3 system. This research demonstrates that the demulsification process of emulsified asphalt can potentially be adjusted by managing the relative content of Na+ and phenyl functional groups in the emulsifier, which gives critical insight into improving the design and construction of asphalt pavements.

Synthesis of 2-substituted-Pyrimidine-based porous aromatic frameworks via oxygen involved biginelli multicomponent polymerization: toward high performance Li–S batteries

Facile, general methods for the preparation of functionalized porous aromatic frameworks (PAFs) are necessary. Herein, we describe a new method for the one-step synthesis of functionalized pyrimidine-based PAFs via oxygen involved Biginelli multicomponent polymerization. As first application instance, we constructed a 2-amino-pyrimidine-based PAF (BPAF-1), and followed by employed it as a sulfur host material for lithium-sulfur batteries. Attributed to its 2-amino-pyrimidine structural superiorities, the BPAF-1/S composites demonstrate excellent electrochemical performance as cathode in lithium-sulfur batteries, such as good cyclability with a high capacity retention of 78.1% after 500 cycles and high rate capability up to 5C. Besides, it is convenient to bring various 2-substituted functional groups such as –OH, –SH, methyl, and phenyl functional groups to pyrimidine-based PAFs under similar conditions, which provided its wide applicability.

In Vitro and In Silico Evaluation of Biological Properties of Some 1, 3, 4-Oxadiazole Derivatives Against Streptococcus mutans and Their Interaction With Gbp-C by Molecular Docking

Background: The need to replace new drug structures for the treatment of resistant strains has become essential. Streptococcus mutans is one of the most important factors in causing tooth decay. Glucan binding protein-C (Gbp-C) is a crucial mobileular floor protein that is worried in biofilm formation, and 1, 3, 4-oxadiazoles are new antibacterial structures. Accordingly, this study focused on assessing in vitro and in silico activity of our previously synthesized compounds of 1, 3, 4-oxadiazole against S. mutans. Methods: To this end, our previously synthesized derivatives were re-synthesized and prepared, and then antibacterial susceptibility tests were used for inhibition zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) test values. The molecular docking method was also applied to confirm the effect of compounds in interaction with the Gbp-C of S. mutans. Results: All compounds showed different effects against the bacterial sample. Among these, the most effective ones were related to naphthalene (4d), fluorophenyl (4e), and dimethoxyphenyl (4h) derivatives against S. mutans, respectively. Other compounds also had antibacterial properties but to a lesser extent. In the molecular part, compounds 4d and 4h had the highest affinity to inhibit the GbpC-protein. compound 4d with amino acids ASP and GLN established 402 and 391 hydrogen bonds, respectively, and compound 4h with amino acids SER, GLU, THR, and TRP established 347, 360, 449, and 451 hydrogen bonds, respectively. Conclusions: In general, 1, 3, 4-oxadiazoles containing naphthalene and dimethoxy phenyl functional groups in high concentrations can be good alternatives to the existing drugs for eliminating caries-causing tooth mutants that have drug resistance. It seems that more inhibitory effects can be observed on clinical specimens by adding different purposeful groups and increasing the destructive power of oxadiazole-based compounds.

Fingermark detection using upconverting nanoparticles and comparison with cyanoacrylate fuming

This paper reports the synthesis of high-quality upconverting nanoparticles (UCNPs) – sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF4:Yb,Er) with a silica shell and capped with phenyl functional groups. The main goal of this research was to design tailor-made UCNPs for fingermark detection, to test and validate a nanoparticle-based detection technique and to compare their performance against a benchmark method to assess potential implementation in routine practice by law enforcement agencies. The water-based UCNPs solution was applied to natural fingermarks on a number of substrates. This is the first ever systematic comparative study between UCNPs and a benchmark fingermark detection technique – cyanoacrylate fuming (CAF) followed by luminescent dye staining. Fingermark detection effectiveness was studied by treating 300 latent fingermark specimens on aluminium foil, polyethylene, polypropylene and glass slides. It was concluded that, on average, CAF performed better across the substrates tested. Nevertheless, UCNPs can be advantageous for fingermark detection on multicoloured, patterned or luminescent substrates due to their unique optical properties. There are, however, shortfalls associated with their synthesis and use that need to be addressed before they can be considered for operational purposes.

Exploration of molecular dynamics for the adsorption of anionic emulsifier on the main chemical composition surface of aggregate

In this study, we conducted molecular simulation and conductivity experiments to systematically explore the adsorption of five anionic emulsifiers on the main chemical composition surface of the aggregate (calcium carbonate: CaCO3, silica: SiO2), which have the same hydrophobic group and different hydrophilic groups. Simulation results and experimental conclusions indicated that the adsorption of the five anionic emulsifiers on the SiO2 surface was stronger than that on the CaCO3 surface. The order of adsorption of the hydrophilic group of the anionic emulsifier on the CaCO3 surface was: benzene sulfonate group (▪) > sulphate group (-OSO3-) > sulfonate group (-SO3-) > diphenyl ether disulfonate group (▪), and that on the SiO2 surface is ▪>-OSO3->-SO3-. These sequences show that the structure of the hydrophilic group of the anionic emulsifier and the degree of branching have an influence on the adsorption of the emulsifier on the CaCO3 and SiO2 surThe adsorption of five anionic emulsifiers on the SiO2 surface is better than faces. The adsorption of anionic emulsifiers on the SiO2 surface is enhanced whereas that on the CaCO3 surface declines with the increase in number of phenyl functional groups. Additionally, the same adsorption characteristics are observed when the branching degree of the hydrophilic group increases. The experimental results fully verified the accuracy of the simulation conclusions. The binding ability of the hydrophilic group of anionic emulsifiers and metal cations is strengthened with an increase in the oxidation of metal cations. Therefore, to avoid early demulsification of emulsified asphalt, it is necessary to prevent the solution from containing a large amount of strong oxidising metal cations under high-mineralization construction conditions. Molecular level micro-information provided by molecular dynamics (MD) can provide guidance for the demulsification of emulsified asphalt and the structural design of the hydrophilic group of the emulsifier.

An Excess Electron Bound to Magnesium Halides and Basic Grignard Compounds (RMgX and RMgR, R = Me, Et, Ph; X = F, Cl, Br).

Grignard reagents are commonly used in organic synthesis, yet their ability to form stable anionic states has not been recognized thus far. In this work, representative examples of RMgF, RMgCl, and RMgBr molecules involving methyl, ethyl, and phenyl functional groups serving as R substituents are investigated regarding their equilibrium structures, adiabatic electron affinities, and vertical electron detachment energies of their daughter anions. The electronic stabilities determined for the negatively charged Grignard compounds are then compared to those predicted for their corresponding magnesium halides. The anions formed by RMgX (R = Me, Et, Ph; X = F, Cl, Br) molecules are found to be adiabatically electronically stable valence-bound systems characterized by relatively large vertical electron detachment energies spanning the 0.79–1.62 eV range. In addition, significant structural relaxation upon attachment of an excess electron is predicted for all Grignard compounds considered. Furthermore, the re-examination of the anions formed by magnesium halides resulted in recognizing them as valence-bound rather than dipole-bound anions, in contrast to the earlier interpretations.

Direct surface functionalization of transparent carbon nanosheet electrodes for organic photovoltaics

Carbon nanosheets (CNSs) were functionalized by a simple dipping approach using phenylhydrazine-based materials to improve their properties as transparent electrodes. X-ray photoelectron spectroscopy was used to investigate the effects of functionalization on the CNS structure and confirm the successful functionalization of phenyl functional groups containing nitrogen and fluorine atoms onto the CNS surface. The functionalized CNSs showed ~32% lower sheet resistance and an up-shifted work function of ~4.8 eV without sacrificing transmittance after being doped with highly electronegative heteroatoms. Accordingly, the functionalized CNS-electrode-based organic photovoltaics exhibited ~13% higher cell efficiency than those based on bare CNSs. These results suggest that direct surface functionalization could improve the performance of CNSs as transparent electrodes.

Identification of N-Nitrosamines and Nitrogenous Heterocyclic Byproducts during Chloramination of Aromatic Secondary Amine Precursors.

With diminishing pristine water, wastewater-affected waters that contain complex anthropogenic compounds are becoming important sources of drinking water and the compounds will inevitably react with disinfectants to form disinfection byproducts (DBPs). Secondary amines such as diphenylamine (DPA) analogues are considered as potential precursors of N-nitrosamines. In this study, an in situ 14N/15N-labeling and screening workflow was used to systematically investigate the formation of nitrogenous DBPs (N-DBPs) and putative reaction pathways. Twenty-four pairs of N-DBPs were generated and identified from chloramination of DPA through two main pathways, in which chloramines reacted with the amino and phenyl functional groups to form N-nitrosodiphenylamine and monochlorinated 5,10-dihydro-phenazine (Cl-DiH-Phe), respectively. Cl-DiH-Phe could further produce phenazine and the coupling products with another DPA molecule. Selective N-DBP formation was pH and dose-dependent, and the same reactions were observed for additional two aromatic DPA analogues. Effects of alkyl substituents on the formation pathways were investigated using a series of dialkyl and N-alkyl aromatic analogues. Only the amino pathway to form nitrosamines was noticed for dialkyl amines, nevertheless, both the main reactions occurred for N-alkyl aromatic amines. These findings suggested that the reaction with chloramines through a phenyl pathway was likely to be crucial for novel nitrogenous heterocyclic byproducts.

Synthesis of Cost-Effective Pomelo Peel Dimethoxydiphenylsilane-Derived Materials for Pyrene Adsorption: From Surface Properties to Adsorption Mechanisms.

This study investigated the adsorption behaviors of pyrene (PYR) on a pomelo peel adsorbent (PPA), biochar (PPB), and H3PO4-modified (HPP), NaOH-activated (NPP), and dimethoxydiphenylsilane-treated (DPDMS-NPP) pomelo peel materials. SEM, FTIR, and elemental analyses of DPDMS-NPP’s surface structure showed that the material was characterized by a well-developed porous structure, a large specific surface area (698.52 m2 g–1), and an abundance of phenyl functional groups. These properties enhance the PYR adsorption performance of DPDMS-NPP. Experimental results indicated that the adsorption capacity of DPDMS-NPP was significantly affected by the amount of material used and the initial concentration of PYR. Kinetic assessments suggested that PYR adsorption on PPA, NPP, and DPDMS-NPP could be accurately described by the pseudo second-order model. The adsorption process was controlled by several mechanisms, including electron donor–acceptor (EDA), electrostatic, and π–π interactions as well as film and intraparticle diffusion. The adsorption isotherm studies showed that PYR adsorption on DPDMS-NPP and PPA was well described by the Langmuir model and the maximum Langmuir adsorption capacity of DPDMS-NPP was 531.9 μg g–1. Overall, the results presented herein suggested that the use of DPDMS-NPP adsorbents constitutes an economic and environmentally friendly approach for the mitigation of PYR contamination risks.

Effect of methacryloxypropyl and phenyl functional groups on crosslinking and rheological and mechanical properties of ladder-like polysilsesquioxane hard coatings

The rheological and mechanical properties of photocurable ladder-like polysilsesquioxanes containing phenyl and methacryloxypropyl groups (LPMA) were investigated. LPMAs with various ratios of the two functional groups were synthesized through the hydrolysis and condensation reactions. The chemical structures of the synthesized LPMAs were confirmed using H1 NMR and FT-IR spectroscopy. The basic rheological properties of the LPMA solutions provided information about their flow properties prior to the curing stage, which was relevant for their application as a hard coating. The curing behaviors of the LPMA solutions under UV irradiation were scrutinized using real-time rheological measurements and rigid-body pendulum tests. These results were well correlated with the surface mechanical properties of the final cured LPMA films measured via nano indentation and scratch tests. The phenyl group was found to play a role in providing rigidity to the cured films, and the methacryloxypropyl group affected crosslinking performance. The physical properties of LPMA samples could be improved for application as a promising inorganic-organic hybrid coating by tuning the ratio of two functional groups.

Glass transition of polystyrene (PS) studied by Raman spectroscopic investigation of its phenyl functional groups

In polymeric materials the glass transition (GT) is a well-known and very important relaxation process related to movements of functional groups in the polymeric chain. In this work, we show the potential of Raman spectroscopy for exploring the GT process in the polymer polystyrene. We collected Raman spectra during a step-by-step heating process of the sample, which allowed us to collect signatures of the GT process from peak parameters of specific vibrational modes, and to verify the GT temperature. Results of the latter were in accordance with published values obtained via other methods. We identified the aromatic ring vibrational modes of the phenyl functional groups to be those which, due to steric hindrance, suffer the largest influence during the GT process. This confirms that Raman spectroscopy can be used as a complementary technique to perform GT investigations in polymeric materials due to its sensitivity to small intermolecular changes affecting vibrational properties of relevant functional side groups.

Synthesis and comprehensive structural studies of a novel amide based carboxylic acid derivative: Non–covalent interactions

The presented work studies the geometric and electronic structures of the crystalline network of a novel amide based carboxylic acid derivative, N–[(4–chlorophenyl)]–4–oxo–4–[oxy] butane amide, C10H10NO3Cl (1), constructed via hydrogen bonds (HBs) and stacking non–covalent interactions. Compound 1 was synthesized and characterized by FTIR, 1H, and 13C NMR, and UV–Vis spectra, X–ray structural, DTA–TG, and EI–MS, analyses. DFT calculations about molecular and related network of 1 were performed at hybrid B3LYP/6–311+G (d, p) level of theory to support the experimental data. The neutral monomeric structures join together via inter−molecular conventional O/NH⋯O and non−conventional CH⋯O HBs and OH···π and CO···π stacking interactions to create 2−D architecture of the network. The results of dispersion corrected density functional theory (DFT−D) calculations within the binding energy of the constructive non−covalent interactions demonstrate that HBs, especially conventional OH⋯O and NH⋯O, govern the network formation. The calculated electronic spectrum show six major bands in the range of 180–270 nm which confirm the experimental one within an intense band around 250 nm. These charge transfer bands result from shift of lone pair electron density of phenyl to chlorine or hydroxyl or phenyl functional groups that possess π → π* and π → n characters.

Synthesis and Characterization of Gold Clusters Ligated with 1,3-Bis(dicyclohexylphosphino)propane.

In this multidisciplinary study the chemical reduction synthesis of novel gold clusters in solution was combined with high-resolution analytical mass spectrometry (MS) to gain insight into the composition of the gold clusters and how their size, ionic charge state, and ligand substitution influences their gas-phase fragmentation pathways. Ultrasmall cationic gold clusters ligated with 1,3-bis(dicyclohexylphosphino)propane (dcpp) were synthesized for the first time and introduced into the gas phase using electrospray ionization (ESI). Mass-selected cluster ions were fragmented by employing collision-induced dissociation (CID) and the product ions were analyzed using MS. The solutions were found to contain the multiply charged cationic gold clusters Au9 L4 3+ , Au13 L5 3+ , Au6 L3 2+ , Au8 L3 2+ , and Au10 L4 2+ (L=dcpp). The gas-phase fragmentation pathways of these cluster ions were examined systematically by employing CID combined with MS. In addition, CID experiments were performed on related gold clusters of the same size and ionic charge state but capped with 1,3-bis(diphenylphosphino)propane (dppp) ligands containing phenyl functional groups at the two phosphine centers instead of cyclohexane rings. It is shown that this relatively small change in the molecular substitution of the two phosphine centers in diphosphine ligands (C6 H11 versus C6 H5 ) exerts a pronounced influence on the size of the species that are preferentially formed in solution during reduction synthesis as well as the gas-phase fragmentation channels of otherwise identical gold cluster ions. The mass spectrometry results indicate that in addition to the length of the alkyl chain between the two phosphine centers, the substituents at the phosphine centers also play a crucial role in determining the composition, size, and stability of diphosphine-ligated gold clusters synthesized in solution.

Direct Synthesis and Solid-State NMR Characterization of Cubic Mesoporous Silica SBA-1 Functionalized with Phenyl Groups

Well-ordered mesoporous silicas SBA-1 (cubic Pm3n symmetry) functionalized with phenyl groups have been synthesized via co-condensation of tetraethoxysilane (TEOS) and phenyltriethoxysilane (PhTES) under acidic conditions. The synthesis parameters such as temperature, type of surfactant, and synthesis composition have been systematically investigated as a function of PhTES contents. The phenyl-containing units are incorporated quantitatively and reach a maximum PhTES loading up to 33 mol % (based on silicon) without a significant degradation of the structural ordering of the Pm3n mesophase. A combination of multinuclear (1H, 13C, 29Si) solid-state NMR and two-dimensional (2D) solid-state NMR correlation techniques such as 13C{1H} and 29Si{1H} HETCOR (heteronuclear correlation) and 1H-1H exchange NMR has been used to establish framework locations of phenyl functional groups that are incorporated in the mesoporous structure and their interactions with the surfactant molecules. 2D 13C{1H} HETCOR NMR experiments reveal that the phenyl moieties are in close spatial proximity to the trimethylammonium headgroups of the cationic surfactant species in the as-synthesized materials, suggesting that there are some specific interactions between them to maintain the surfactant packing parameter (g) smaller than 1/3 necessary for the formation of the cubic mesophase. The detection of couplings between the protons associated with various 29Si species via 29Si{1H} HETCOR NMR established that the T silicon species due to the phenyl groups incorporated are in closer proximity to the Q4 silicon species than to the Q3 silicon species. This observation also provides direct molecular-level evidence for the co-condensation of PhTES and TEOS in the synthesis of mesoporous organosilicas.

Selective resonance population in high resolution electron energy loss spectroscopy of 4-ethylbenzenethiol self-assembled monolayers on Au(1 1 1)

We have investigated the vibrational frequencies and excitation cross-section of self-assembled monolayers (SAMs) of 4-ethylbenzenethiol (CH 3CH 2(C 6H 4)SH) on Au(1 1 1) by high resolution electron energy loss spectroscopy (HREELS). Negative ion resonances were observed in the energy loss intensities as a function of the incident electron energy. Analysis of the C–H stretching modes indicates resonances of different energies are localised in both the ethyl and phenyl functional groups of the SAM molecules, which regulate the observed vibrational lineshape.

Synthesis of optically active cyanohydrins from aromatic ketones: evidence of an increased substrate range and inverted stereoselectivity for the hydroxynitrile lyase from Linum usitatissimum

The synthesis of ( R)- and ( S)-cyanohydrins from a range of aromatic methyl and ethyl ketones, including the first examples from substituted variants of phenylacetone, benzylacetone and propiophenone, is described. Commercially available hydroxynitrile lyase (HNL) enzymes were used to catalyze the asymmetric addition of cyanide to the ketones, including the first successful application of the flax HNL (LuHNL) to the synthesis of any aromatic ( S)-cyanohydrin. Both reaction yields and stereoselectivities were shown to be influenced by the carbon chain length between the ketone and phenyl functional groups, and the type of aromatic substitution present on the starting material. Substrates converted with the greatest degree of productivity and selectivity were phenylacetones with large, electron withdrawing meta-substituents, such as 3-Cl, 3-Br and 3-CF 3 phenylacetones, from which cyanohydrins are formed with 93–99% ee and 61–71% yield.

Theoretical Studies of Monosubstituted and Higher Phenyl-Substituted Octahydrosilsesquioxanes

The electronic and structural properties of molecules (octahydrosilsesquioxane, H 8Si8O12), the monosubstituted and higher phenyl-substituted octahydrosilsesquioxanes (PhH7Si8O12 ,P h 2H6Si8O12, (Ph-Ph)H7Si8O12, and Ph8Si8O12), and crystals (H8Si8O12 and octa(phenylsilsesquioxane) acetone solvate (C48H40O12Si8‚C3H6O)) have been studied using plane-wave (PW), pseudo-potential (PP), and density functional theory and the generalized gradient approximation (DFT-GGA) methods. The results show that the orbitals near the highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) (inclusive) for the phenylsubstituted polyhedral oligomeric silsesquioxane clusters and crystal are localized on the phenyl functional groups, whereas for both isolated molecular and crystalline H8Si8O12, the HOMO is that with the lone pair on the O atoms.