Branched Alkyl Groups Research Articles

Data-driven optimization of the in silico design of ionic liquids as interfacial cell culture fluids

ABSTRACT As an alternative to conventional plastic dishes, the interface between water-immiscible hydrophobic fluids, such as perfluorocarbons and silicones, permits cell adhesion and growth. Thus, it is expected to replace the petroleum-derived products in a sustainable society. However, most hydrophobic fluids are cytotoxic, which limits the range of mechanical and chemical cues exposed to the cells. Using a data-driven approach, this study aimed to identify non-cytotoxic ionic liquids (ILs) as fluid culture platforms to take advantage of their ‘designer’ nature for broadening the possible physicochemical ranges exposed to cells and their repeated use owing to their high heat stability before their biological applications. The new candidates within the readily synthesize ammonium-type ILs were identified through the active cycle of regression and a limited number of cytotoxicity tests. Structure – cytotoxicity analysis indicated that the presence of multiple long alkyl branches was critical for low cytotoxicity. Particularly, we successfully cultured human mesenchymal stem cells (hMSCs) at the trihexylethylammonium trifluoromethylsulfonylimide interface and repeated their use after solvent extraction and heat sterilization. This study identified non-cytotoxic ILs that fulfill plastics’ 3 R ( R educe, R ecycle, and R eplace) requirements and opens new avenues for hMSC fate manipulation through mechanotransduction.

Influence of terminal moiety on PCE of DSSCs: An In Silico study based on triazatruxene-benzothiadiazole dye

Our study utilized an experimentally synthesized dye as a reference molecule, employing a donor-π linker-acceptor (D-π-A) framework for organic solar cells. The molecule featured a triazatruxene group linked with alkyl branches as the donor and ethynyl benzoic acid as the acceptor, connected through a derivative of benzothiadiazole as the π linker. To improve optoelectronic and photovoltaic properties, ten theoretically designed dyes (ZA1–ZA10) are proposed, differing from the reference (R) by modifying the terminal acceptor moiety. Various quantum analyses, including frontier molecular orbitals, optical properties, reorganization energies, binding energies, transition density matrices (TDM), molecular electrostatic potential (MEP), dipole moment, and density of states were carried out at DFT/B3LYP/6-31G(d,p). Ground state geometries revealed a co-planar morphology in ZA1–ZA10, facilitating efficient charge transportation. TDM and MEP illustrated improved electronic transitions in the excited states. Computational analyses revealed superior photovoltaic properties of ZA1–ZA10. Notably, ZA5 exhibited the most significant redshift (1021 nm) in absorption, lowest bandgap (1.44 eV), smallest transition energy (1.21 eV), least binding energy (0.23 eV), and improved charge mobilities. Results from the adsorption of ZA1-ZA10 on the TiO2 layer confirmed their anchoring potential and effective injection of electrons to anatase (TiO2)9. These significant outcomes promise the potential and novelty of our designed dyes for higher power conversion efficiencies (PCE) in dye-sensitized solar cells (DSSCs).

Effect of branching in the alkyl chain of diglycolamide on the sequestration of tetravalent actinides: solvent extraction and theoretical studies.

DGA (diglycolamide) ligands show a different extraction behavior of trivalent metal ions by changing the branching alkyl chain length as well as the branching at the methylene position. There are no studies of these factors on the extraction efficiency of these DGA derivatives for the extraction of tetravalent actinides. We have evaluated four different DGA derivatives for the extraction of Np, Pu, and Th from molecular diluents. The n-butyl derivative shows enhanced extraction efficiency and branching gives rise to a reduction in the extraction efficiency of tetravalent ions. The distribution ratios are higher in pure octanol than in a mixture of 30% octanol and 70% n-dodecane. This behavior is in marked difference to that of the extraction of trivalent ions where the addition of an alcohol generally decreases the distribution ratio of trivalent ions due to the ligand-modifier intercation, poor aggregation or micelle formation tendency of DGAs in polar solvents. This suggests that micelle-mediated extraction may not be the dominating factor for the extraction of tetravalent metal ions. Slope analysis suggests the involvement of only two DGA molecules in the extracted species suggesting no/poor possibility of micelle formation in the present system. The higher extraction in pure octanol may be due to a better solubility of the extracted complexes in this polar medium compared to the mixture of octanol and n-dodecane. The water and acid uptake, the back extraction, and the radiation stability of the solvent systems were also investigated. DFT studies were performed to get a better insight into the extraction and complexation of the different DGA solvent systems.

Prediction of Nernst coefficient of S-containing compounds between fuel and ionic liquid phases in the extractive desulfurization using linear and supported vector machine (SVM) methods: QSPR-based machine learning

BackgroundThe presence of sulfur-containing compounds (SCCs) in the refinery streams has significant economic and environmental implications. Great attention has been focused on finding the proper green solvents like ionic liquids (ILs11Ionic liquids) with efficient extraction performance as a matter of concern of environmental issues. MethodsThe research aimed to develop a predictive model using QSPR to forecast the partition coefficient of dibenzothiophene by ILs from n-dodecane. Utilizing a dataset of 54 ILs and their partition coefficients for DBT, the study employed two methods to optimize ILs structures and compared linear (GA-MLR) and non-linear (LS-SVM) models, with non-linear models showing higher accuracy. After initial modeling and assessing the primary dataset of 54 ILs, yielding an R2 parameter of 0.39 for the test set, the dataset was divided into smaller clusters for further analysis. Three additional clusters were investigated. The second cluster comprised 14 ILs with identical cations and varying anions, modeled with two descriptors. The third cluster, consisting of 21 ILs with imidazolium cations and diverse anions, was modeled with three descriptors. Lastly, the fourth cluster, comprising 26 ILs with different cations but the same anion, was also modeled with three descriptors. Significant findingsThe MLR model yielded R2 values of 0.98, 0.85, and 0.93 for the test sets of the second, third, and fourth clusters respectively. Effective descriptors, including cation polarizability and alkyl branch length, were examined for their impact on partition coefficient and desulfurization efficiency. This research aids in enhancing EDS processes with ILs, advancing more efficient desulfurization technologies.

Flavonoid as a Potent Antioxidant: Quantitative Structure-Activity Relationship Analysis, Mechanism Study, and Molecular Design by Synergizing Molecular Simulation and Machine Learning.

In this work, a quantitative structure-antioxidant activity relationship of flavonoids was performed using a machine learning (ML) method. To achieve lipid-soluble, highly antioxidant flavonoids, 398 molecular structures with various substitute groups were designed based on the flavonoid skeleton. The hydrogen dissociation energies (ΔG1, ΔG2, and ΔG3) related to multiple hydrogen atom transfer processes and the solubility parameter (δ) of flavonoids were calculated using molecular simulation. The group decomposition results and the calculated antioxidant parameters constituted the ML data set. The artificial neural network and random forest models were constructed to predict and analyze the contribution of the substitute groups and positions to the antioxidant activity. The results showed the hydroxyl group at positions B4', B5', and B6' and the branched alkyl group at position C3 in the flavonoid skeleton were the optimal choice for improving antioxidant activity and compatibility with apolar organic materials. Compared to the pyrogallol group-grafted flavonoid, the designed potent flavonoid decreased ΔG1 and δ by 2.2 and 15.1%, respectively, while ΔG2 and ΔG3 kept the favorable lower values. These findings suggest that an efficient flavonoid prefers multiple ortho-phenolic hydroxyl groups and suitable sites with hydrophobic groups. The combination of molecular simulation and the ML method may offer a new research approach for the molecular design of novel antioxidants.

Dye-sensitized solar cells based on D—A—π—A′ structures with a 4H-cyclopenta[2,1-b:3,4-b′]dithiophene fragment containing branched alkyl groups

Dye-sensitized solar cells based on D—A—π—A′ structures with a 4H-cyclopenta[2,1-b:3,4-b′]dithiophene fragment containing branched alkyl groups

Unraveling the thermodynamic and clouding interactions of non-ionic micelles of polyethylene glycol tert-octylphenyl ether in water-ethanolamine mixtures: Effect of temperature and composition

The amines are potentially used as co-surfactants in an emulsion. The formation of mixed–micelle in the mixture of non-ionic surfactant polyethylene glycol tert-octyl phenyl ether (TX-114) in the water-ethanolamine mixed solvent system has been studied by the cloud point method at variable concentrations. In absence of any added compound, CP shows concentration-dependent variation. The values of CP in an aqueous medium are found to increase by enhancing their concentration range. The CP values of 1 % TX-114 solutions were found to either remain steady at lower concentrations and elevated at higher concentrations in the presence of secondary and tertiary ethanolamine. The CP decreases with an increasing number of ethanolic groups, while CP increases with alkyl branching. The ethanolamine's amines show CP variation by insinuating between the head part with proton rich amine groups at the micelle layer. The outcomes are examined within the light of a specific additive's capacity to evacuate water from the head gathering of the surfactant micelles. The stability of mixed micelle system has also been evaluated by foam ability and foam stability data.

Modeling the influence of carbon branching structure on secondary organic aerosol formation via multiphase reactions of alkanes

Abstract. Branched alkanes represent a significant proportion of hydrocarbons emitted in urban environments. To accurately predict the secondary organic aerosol (SOA) budgets in urban environments, these branched alkanes should be considered as SOA precursors. However, the potential to form SOA from diverse branched alkanes under varying environmental conditions is currently not well understood. In this study, the Unified Partitioning Aerosol Phase Reaction (UNIPAR) model is extended to predict SOA formation via the multiphase reactions of various branched alkanes. Simulations with the UNIPAR model, which processes multiphase partitioning and aerosol-phase reactions to form SOA, require a product distribution predicted from an explicit gas kinetic mechanism, whose oxygenated products are applied to create a volatility- and reactivity-based αi species array. Due to a lack of practically applicable explicit gas mechanisms, the prediction of the product distributions of various branched alkanes was approached with an innovative method that considers carbon lengths and branching structures. The αi array of each branched alkane was primarily constructed using an existing αi array of the linear alkane with the nearest vapor pressure. Generally, the vapor pressures of branched alkanes and their oxidation products are lower than those of linear alkanes with the same carbon number. In addition, increasing the number of alkyl branches can also decrease the ability of alkanes to undergo autoxidation reactions that tend to form low-volatility products and significantly contribute to alkane SOA formation. To account for this, an autoxidation reduction factor, as a function of the degree and position of branching, was applied to the lumped groups that contain autoxidation products. The resulting product distributions were then applied to the UNIPAR model for predicting branched-alkane SOA formation. The simulated SOA mass was compared to SOA data generated under varying experimental conditions (i.e., NOx levels, seed conditions, and humidity) in an outdoor photochemical smog chamber. Branched-alkane SOA yields were significantly impacted by NOx levels but insignificantly impacted by seed conditions or humidity. The SOA formation from branched and linear alkanes in diesel fuel was simulated to understand the relative importance of branched and linear alkanes with a wide range of carbon numbers. Overall, branched alkanes accounted for a higher proportion of SOA mass than linear alkanes due to their higher contribution to diesel fuel.

N-Alkylcorroles

A series of inner core [Formula: see text]-alkylcorroles were synthesized and characterized. The introduction of both linear and branched alkyl groups was achieved, demonstrating the quite large scope of the reaction. Polyalkylation results in the formation of the [Formula: see text]-21,[Formula: see text]-22 regioisomer, although the introduction of the second alkyl group is less facile than previously observed in the case of the methyl substituent. Complete functionalization of the inner core nitrogens has been investigated, but only the N,N′,N″-trimethyl derivatives were obtained. The characterization of these species demonstrated a different arrangement of the methyl groups to the macrocyclic plane, which is peculiar when compared with the conformation of the analogous porphyrin derivatives. These [Formula: see text]-alkylcorroles should prove to be of potential interest as ligands for various metal ions.

Li-selective calix[4]arene with trialkyl-monoacetic acid groups: effect of three alkyl branches and t-octyl groups at p-position on selectivity for Li extraction

Li-selective calix[4]arene with trialkyl-monoacetic acid groups: effect of three alkyl branches and t-octyl groups at p-position on selectivity for Li extraction

Effect of Position of Donor Units and Alkyl Groups on Dye-Sensitized Solar Cell Device Performance: Indoline-Aniline Donor-Based Visible Light Active Unsymmetrical Squaraine Dyes.

Indoline (In) and aniline (An) donor-based visible light active unsymmetrical squaraine (SQ) dyes were synthesized for dye-sensitized solar cells (DSSCs), where the position of An and In units was changed with respect to the anchoring group (carboxylic acid) to have In-SQ-An-CO2H and An-SQ-In-CO2H sensitizers, AS1-AS5. Linear or branched alkyl groups were functionalized with the N atom of either In or An units to control the aggregation of the dyes on TiO2. AS1-AS5 exhibit an isomeric π-framework where the squaric acid unit is placed in the middle, where AS2 and AS5 dyes possess the anchoring group connected with the An donor, and AS1, AS3, and AS4 dyes having the anchoring group connected with the In donor. Hence, the conjugation between the middle squaric acid acceptor unit and the anchoring -CO2H group is short for AS2, AS5, and AK2 and longer for AS1, AS3, and AS4 dyes. AS dyes showed absorption between 501 and 535 nm with extinction coefficients of 1.46-1.61 × 105 M-1 cm-1. Further, the isomeric π-framework of An-SQ-In-CO2H and In-SQ-An-CO2H exhibited by means of changing the position of In and An units a bathochromic shift in the absorption properties of AS2 and AS5 compared to the AS1, AS3, and AS4 dyes. The DSSC device fabricated with the dyes contains short acceptor-anchoring group distance (AS2 and AS5) showed high photovoltaic performances compared to the dyes having longer distance (AS1, AS3, and AS4) with the iodolyte (I-/I3-) electrolyte. DSSC device efficiencies of 5.49, 6.34, 6.16, and 5.57% have been achieved for AS1, AS2, AS3, and AS4 dyes, respectively; without chenodeoxycholic acid (CDCA), small changes have been observed in the device performance of the AS dyes with CDCA. Significant changes have been noted in the DSSC parameters (open-circuit voltage VOC, short-circuit current JSC, fill factor ff, and efficiency η) for the AS5 dye while sensitized with CDCA and showed highest DSSC efficiency of 8.01% in the AS dye series. This study revealed the potential of shorter SQ acceptor-anchoring group distance over the longer one and the importance of alkyl groups on the overall DSSC device performance for the unsymmetrical squaraine dyes.

Amino-Acid-Derived Anionic Polyacrylamides with Tailored Hydrophobicity-Physicochemical Properties and Cellular Interactions.

Polyanions can internalize into cells via endocytosis without any cell disruption and are therefore interesting materials for biomedical applications. In this study, amino-acid-derived polyanions with different alkyl side-chains are synthesized via postpolymerization modification of poly(pentafluorophenyl acrylate), which is synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization, to obtain polyanions with tailored hydrophobicity and alkyl branching. The success of the reaction is verified by size-exclusion chromatography, NMR spectroscopy, and infrared spectroscopy. The hydrophobicity, surface charge, and pH dependence are investigated in detail by titrations, high-performance liquid chromatography, and partition coefficient measurements. Remarkably, the determined pK a-values for all synthesized polyanions are very similar to those of poly(acrylic acid) (pK a = 4.5), despite detectable differences in hydrophobicity. Interactions between amino-acid-derived polyanions with L929 fibroblasts reveal very slow cell association as well as accumulation of polymers in the cell membrane. Notably, the more hydrophobic amino-acid-derived polyanions show higher cell association. Our results emphasize the importance of macromolecular engineering toward ideal charge and hydrophobicity for polymer association with cell membranes and internalization. This study further highlights the potential of amino-acid-derived polymers and the diversity they provide for tailoring properties toward drug delivery applications.

In situ combinatorial synthesis of degradable branched lipidoids for systemic delivery of mRNA therapeutics and gene editors

The ionizable lipidoid is a key component of lipid nanoparticles (LNPs). Degradable lipidoids containing extended alkyl branches have received tremendous attention, yet their optimization and investigation are underappreciated. Here, we devise an in situ construction method for the combinatorial synthesis of degradable branched (DB) lipidoids. We find that appending branch tails to inefficacious lipidoids via degradable linkers boosts mRNA delivery efficiency up to three orders of magnitude. Combinatorial screening and systematic investigation of two libraries of DB-lipidoids reveal important structural criteria that govern their in vivo potency. The lead DB-LNP demonstrates robust delivery of mRNA therapeutics and gene editors into the liver. In a diet-induced obese mouse model, we show that repeated administration of DB-LNP encapsulating mRNA encoding human fibroblast growth factor 21 alleviates obesity and fatty liver. Together, we offer a construction strategy for high-throughput and cost-efficient synthesis of DB-lipidoids. This study provides insights into branched lipidoids for efficient mRNA delivery.

The relationship between oxidative degradation and ammonia emission of carbon capture amines based on their chemical structures

Abstract This work investigates the effect of chemical structural positioning of different functional groups in 29 amines covering primary, secondary and tertiary alkanolamines as well as multi-alkylamines and cyclic amines on both amine degradation and ammonia (NH3) emissions during post-combustion amine-based carbon dioxide capture. The results helped to elucidate possible relationships between degradation and emissions as related to the chemical structure of the amine. The results showed that longer alkyl chain lengths in multi-alkylamines caused a more drastic decrease in both degradation and NH3 emissions followed by secondary alkanolamines. The decrease in those activities for primary and tertiary alkanolamines as well as cyclic amines was low and more so for NH3 emissions. In contrast, the increase in hydroxyl groups in secondary alkanolamines caused a drastic increase in degradation and NH3 emissions. On the other hand, having more hydroxyl groups in sterically hindered primary and tertiary alkanolamines caused a more drastic decrease in degradation and a smaller decrease in NH3 emissions due to the steric hindrance within their structure. An increase in the number of amino groups in an amine caused an increase in both degradation and NH3 emission rates because these provided the reactive sites for the formation of free radicals. This effect was not as large in alkyl-cyclic amines as in multi-alkylamines due to the ability of the former to resist oxidative degradation. Furthermore, branched alkyl groups between amino and hydroxyl groups more drastically increased both the degradation and NH3 emission activities than branched alkyl groups located at the nitrogen atom.

Predicting the effect of framework and hydrocarbon structure on the zeolite-catalyzed beta-scission.

Developing improved zeolites is essential in novel sustainable processes such as the catalytic pyrolysis of plastic waste. This study used density functional theory to investigate how alkyl chain length, unsaturated bonds, and branching affect β-scission kinetics in four zeolite frameworks, a key reaction in hydrocarbon cracking. The activation enthalpy was evaluated for a wide variety of 23 hydrocarbons, with 6 to 12 carbon atoms, in FAU, MFI, MOR, and TON. The consideration of both branched and linear olefin and diolefin reactants for the β-scission indicates how the reactant structure influences the intrinsic cracking kinetics, which is especially relevant for the catalytic cracking of plastic waste feedstocks. Intrinsic chemical effects, such as resonance stabilization, the inductive effect, and pore stabilization were found to provide an essential contribution to the activation enthalpy. Additionally, a predictive group additive model incorporating a novel so-called "pore confinement descriptor" was developed for fast prediction of the β-scission activation barrier of a wide range of molecules in the four zeolites. The obtained model can serve as an input for detailed kinetic models in zeolite-catalyzed cracking reactions. The acquired fundamental insights in the cracking of hydrocarbons, relevant for renewable feedstocks, correspond well with experimental observations and will facilitate an improved rational zeolite design.

Effect of UV-absorbing small molecule dyes with different alkyl chain densities and branching positions on the photovoltaic performance of semitransparent DSSCs

To achieve dye-sensitized solar cells (DSSCs) with high transparency, multi-color capability, and long-term durability for future applications across various fields.

Solution-processable quinoidal compounds containing heterocycle for air-stable n‑type organic field-effect transistors and gas sensors

Organic field effect transistors (OFETs) have potential applications in gas sensing area, but the performance and diversity of n-type OFETs are still far behind that of p-type OFETs due to the poor stability in air atmosphere. Herein, a series of novel dicyanomethylene-terminated quinoids compounds were synthesized and characterized by using electron withdrawing aromatic heterocycles as the core structural units. The introduction of alkyl branch chain greatly improves the solubility, which is helpful to the preparation of thin film OFETs devices by low-cost solution method. These OFETs show typical n-channel FET characteristics with mobility ranging from 10−3∼10−1 cm2V−1s−1. Among them, the 3-T-TZCN based OFETs exhibit the best stability, in which the mobility decreased no more than 18 % after 90 days stored in air atmosphere, this is an outstanding performance compared with the previous researches. We further investigated the dimethyl methylphosphonate (DMMP, which is a substitute for detecting sarin) gas sensing performance of each material, the experimental results indicated that the sensitivity, recovery and stability of 3-T-TZCN are better than other materials, and the limit of detection can be lower to 10 ppb level. This general approach could offer new solution for constructing n-type OFET-based gas sensors with good stability in air atmosphere.

Lysozyme aggregation and unfolding in ionic liquid solvents: Insights from small angle X-ray scattering and high throughput screening

Understanding protein behaviour is crucial for developing functional solvent systems. Ionic liquids (ILs) are designer salts with versatile ion combinations, where some suppress unfavourable protein behaviour. This work utilizes small angle X-ray scattering (SAXS) to investigate the size and shape changes of model protein hen egg white lysozyme (HEWL) in 137 IL and salt solutions. Guinier, Kratky, and pair distance distribution analysis were used to evaluate the protein size, shape, and aggregation changes in these solvents. At low IL and salt concentration (1 mol%), HEWL remained monodispersed and globular. Most ILs increased HEWL size compared to buffer, while the nitrate and mesylate anions induced the most significant size increases. IL cation branching, hydroxyl groups, and longer alkyl chains counteracted this size increase. Common salts exhibited specific ion effects, while the IL effect varied with concentration due to complex ion-pairing. Protein aggregation and unfolding occurred at 10 mol% IL, altering the protein shape, especially for ILs with multiple alkyl chains on the cation, or with a mesylate/nitrate anion. This study highlights the usefulness of adopting a high-throughput SAXS strategy for understanding IL effects on protein behaviour and provides insights on controlling protein aggregation and unfolding with ILs.

B─N Covalent Bond-Based Nonfullerene Electron Acceptors for Efficient Organic Solar Cells.

The optoelectronic properties and photovoltaic performance of nonfullerene electron acceptors (NFEAs) in organic solar cells (OSCs) are greatly influenced by the rational structure regulation of the central core unit. This study introduces a novel type of six-membered fused electron-donating core containing B─N covalent bonds to construct acceptor-donor-acceptor (A-D-A)-type NFEAs. By modulating the branching alkyl chains on the nitrogen atom, two NFEAs, BN910 and BN1014, are synthesized and characterized. Both molecules exhibit strong near-infrared absorption, narrow bandgaps (≈1.45eV), appropriate energy levels, and tunable molecular packing behaviors, positioning them as promising candidates for efficient NFEAs in OSCs. The investigation reveals that BN1014, with longer and C2-branched alkyl chains, demonstrates superior intermolecular packing and morphology within active layers, leading to enhanced exciton dissociation, improved charge transfer, and reduced charge recombination in OSCs. As a result, a power conversion efficiency (PCE) of 10.02% is achieved for D18:BN1014-based binary OSCs. Notably, BN1014 can be utilized as the third component in the D18:DT-Y6 binary system to fabricate the ternary OSCs, and a PCE of 17.65% is achieved, outperforming 17.05% of D18:DT-Y6-based binary OSCs. These findings highlight the potential of heteroarenes featuring B─N covalent bonds for constructing high-efficiency NFEAs in OSCs.

Isopropyl‐branched lard and its potential application as a bio‐based lubricant

AbstractRegular lard (RL) was chemically modified into isopropyl‐branched lard (BL). The isopropyl group was introduced into the triglyceride structure via a reaction of carbon–carbon double with isopropyl bromide in presence of ethylaluminum sesquichloride. The reaction was confirmed with gas chromatography–mass spectroscopy, nuclear magnetic resonance, infrared spectroscopy. The physical, tribological and chemical properties of the RL, BL and their blendings in polyalphaolefin (PAO) and high‐oleic sunflower oil (HOSuO) were investigated. The BL exhibited better solubility both in HOSuO and PAO than RL. Compared to RL, BL exhibited higher density, viscosity, improved oxidative stability and cold flow properties both as a neat material and blendings in HOSuO or PAO. However, BL displayed lower viscosity index (197 vs. 162) compared to RL. Both RL and BL displayed similar lubricity as HOSuO and showed potential such as a good lubricity additive in PAO even in small amounts (~10 wt%). This study reveals introducing alkyl branching into lard can lead to improved physico‐chemical properties and lubrication performance.