Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89.173
Filtrar
1.
Int J Mol Sci ; 22(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34445657

RESUMO

In this paper, we present a formulation of highly correlated Fock-space multi-reference coupled-cluster (FSMRCC) methods, including approximate triples on top of the FSMRCC with singles and doubles, which correct the electron affinities by at least at third and up to the fourth order in perturbation. We discuss various partial fourth-order schemes, which are reliable and yet computationally more efficient than the full fourth-order triples scheme. The third-order scheme is called MRCCSD+T*(3). We present two approximate fourth-order schemes, MRCCSD+T*-a(4) and MRCCSD+T*(4). The results that are presented allow one to choose an appropriate fourth-order scheme, which is less expensive and right for the problem. All these schemes are based on the effective Hamiltonian scheme, and provide a direct calculation of the vertical electron affinities. We apply these schemes to a prototype Li2 molecule, using four different basis sets, as well as BeO and CH+. We have calculated the vertical electron affinities of Li2 at the geometry of the neutral Li2 molecule. We also present the vertical ionization potentials of the Li2 anion at the geometry of the anion ground state. We have also shown how to calculate adiabatic electron affinity, though in that case we lose the advantages of direct calculation. BeO has been examined in two basis sets. For CH+, four different basis sets have been used. We have presented the partial fourth-order schemes to the EA in all the basis sets. The results are analyzed to illustrate the importance of triples, as well as highlight computationally efficient partial fourth-order schemes. The choice of the basis set on the electron affinity calculation is also emphasized. Comparisons with available experimental and theoretical results are presented. The general fourth-order schemes, which are conceptually equivalent with the Fock-space multi-reference coupled-cluster singles, doubles, and triplets (MRCCSD+T) methods, based on bondonic formalism, are also presented here in a composed way, for quantum electronic affinity.


Assuntos
Algoritmos , Elétrons , Lítio/química , Modelos Químicos , Teoria Quântica , Fenômenos Físicos
2.
J Phys Chem Lett ; 12(32): 7671-7687, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34351771

RESUMO

Carbon dots (CDs) have excellent luminescence characteristics, such as good light stability, high quantum yield (QY), long phosphorescence lifetime, and a wide emission wavelength range, resulting in CDs' great success in optical applications. Understanding the structure-property relationships in CDs is essential for their use in optoelectronic applications. However, because of the complex nature of CD structures and synthesis processes, understanding the luminescence mechanism and structure-property relationships of CDs is a big challenge. This Perspective reviews the theoretical efforts toward the understanding of structure-property relationships and discusses the challenges that need to be overcome in future development of CDs.


Assuntos
Corantes Fluorescentes/química , Pontos Quânticos/química , Carbono/química , Teoria da Densidade Funcional , Fluorescência , Corantes Fluorescentes/síntese química , Aprendizado de Máquina , Modelos Químicos , Relação Estrutura-Atividade
3.
J Phys Chem Lett ; 12(32): 7708-7716, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34355897

RESUMO

NOx emission heavily affects our environment and human health. Photocatalytic denitrification (deNOx) attracted much attention because it is low-cost and nonpolluting, but undesired nitrite and nitrate were produced in reality, instead of harmless N2. Unveiling the active sites and the photocatalytic mechanism is very important to improve the process. Herein, we have employed a combinational scenario to investigate the reaction mechanism of NO2 and H2O on anatase TiO2(101). On the one hand, a polaron-corrected GGA functional (GGA + Lany-Zunger) was applied to improve the description of electronic states in photoassisted processes. On the other hand, a reaction phase diagram (RPD) was established to understand the (quasi) activity trend over both perfect and defective surfaces. It was found that a perfect surface is more active via the Eley-Rideal mechanism without NO2 adsorption, while the activity on defective surfaces is limited by the sluggish recombinative desorption. A photogenerated hole can weaken the OH* adsorption energies and circumvents the scaling relation of the dark reaction, eventually enhancing the deNOx activity significantly. The insights gained from our work indicate that tuning the reactivity by illumination-induced localized charge and diverse reaction pathways are two methods for improving adsorption, dissociation, and desorption processes to go beyond the conventional activity volcano plot limit of dark conditions.


Assuntos
Dióxido de Nitrogênio/química , Titânio/química , Adsorção , Catálise/efeitos da radiação , Cinética , Modelos Químicos , Termodinâmica , Titânio/efeitos da radiação , Raios Ultravioleta , Água/química
4.
ACS Appl Mater Interfaces ; 13(33): 39868-39879, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34383459

RESUMO

Wearable electronic devices have attracted significant attention as important components in several applications. Among various wearable electronic devices, interest in textile electronic devices is increasing because of their high deformability and portability in daily life. To develop textile electronic devices, fiber-based electronic devices should be fundamentally studied. Here, we report a stretchable and sensitive fiber strain sensor fabricated using only harmless materials during an in situ formation process. Despite using a mild and harmless reducing agent instead of typical strong and hazardous reducing agents, the developed fiber strain sensors feature a low initial electrical resistance of 0.9 Ω/cm, a wide strain sensing range (220%), high sensitivity (∼5.8 × 104), negligible hysteresis, and high stability against repeated stretching-releasing deformation (5000 cycles). By applying the fiber sensors to various textiles, we demonstrate that the smart textile system can monitor various gestures in real-time and help users maintain accurate posture during exercise. These results will provide meaningful insights into the development of next-generation wearable applications.


Assuntos
Nanopartículas Metálicas/química , Prata/química , Têxteis , Dispositivos Eletrônicos Vestíveis , Condutividade Elétrica , Desenho de Equipamento , Humanos , Modelos Químicos , Monitorização Fisiológica , Oxirredução , Propriedades de Superfície
5.
Ultrason Sonochem ; 77: 105700, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34364068

RESUMO

In this study, microcapsules were prepared by spray drying and embedding hemp seed oil (HSO) with soy protein isolate (SPI) and maltodextrin (MD) as wall materials. The effect of ultrasonic power on the microstructure and characteristics of the composite emulsion and microcapsules was studied. Studies have shown that ultrasonic power has a significant impact on the stability of composite emulsions. The particle size of the composite emulsion after 450 W ultrasonic treatment was significantly lower than the particle size of the emulsion without the ultrasonic treatment. Through fluorescence microscopy observation, HSO was found to be successfully embedded in the wall materials to form an oil/water (O/W) composite emulsion. The spray-dried microcapsules showed a smooth spherical structure through scanning electron microscopy (SEM), and the particle size was 10.7 µm at 450 W. Fourier transform infrared (FTIR) spectroscopy analysis found that ultrasonic treatment would increase the degree of covalent bonding of the SPI-MD complex to a certain extent, thereby improving the stability and embedding effect of the microcapsules. Finally, oxidation kinetics models of HSO and HSO microcapsules were constructed and verified. The zero-order model of HSO microcapsules was found to have a higher degree of fit; after verification, the model can better reflect the quality changes of HSO microcapsules during storage.


Assuntos
Cannabis/química , Modelos Químicos , Extratos Vegetais/química , Polissacarídeos/química , Proteínas de Soja/química , Ondas Ultrassônicas , Cápsulas , Cinética , Oxirredução
6.
J Chem Phys ; 155(5): 055103, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34364345

RESUMO

Light harvesting as the first step in photosynthesis is of prime importance for life on earth. For a theoretical description of photochemical processes during light harvesting, spectral densities are key quantities. They serve as input functions for modeling the excitation energy transfer dynamics and spectroscopic properties. Herein, a recently developed procedure is applied to determine the spectral densities of the pigments in the minor antenna complex CP29 of photosystem II, which has recently gained attention because of its active role in non-photochemical quenching processes in higher plants. To this end, the density functional-based tight binding (DFTB) method has been employed to enable simulation of the ground state dynamics in a quantum-mechanics/molecular mechanics (QM/MM) scheme for each chlorophyll pigment. Subsequently, the time-dependent extension of the long-range corrected DFTB approach has been used to obtain the excitation energy fluctuations along the ground-state trajectories also in a QM/MM setting. From these results, the spectral densities have been determined and compared for different force fields and to spectral densities from other light-harvesting complexes. In addition, time-dependent and time-independent excitonic Hamiltonians of the system have been constructed and applied to the determination of absorption spectra as well as exciton dynamics.


Assuntos
Complexos de Proteínas Captadores de Luz/química , Complexo de Proteína do Fotossistema II/química , Clorofila/química , Teoria da Densidade Funcional , Modelos Químicos , Simulação de Dinâmica Molecular , Termodinâmica
7.
Nat Commun ; 12(1): 4874, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385442

RESUMO

Biobased poly(γ-methyl-α-methylene-γ-butyrolactone) (PMMBL), an acrylic polymer bearing a cyclic lactone ring, has attracted increasing interest because it not only is biorenewable but also exhibits superior properties to petroleum-based linear analog poly(methyl methacrylate) (PMMA). However, such property enhancement has been limited to resistance to heat and solvent, and mechanically both types of polymers are equally brittle. Here we report the expeditious synthesis of well-defined PMMBL-based ABA tri-block copolymers (tri-BCPs)-enabled by dual-initiating and living frustrated Lewis pairs (FLPs)-which are thermoplastic elastomers showing much superior mechanical properties, especially at high working temperatures (80-130 °C), to those of PMMA-based tri-BCPs. The FLPs consist of a bulky organoaluminum Lewis acid and a series of newly designed bis(imino)phosphine superbases bridged by an alkyl linker, which promote living polymerization of MMBL. Uniquely, such bisphosphine superbases initiate the chain growth from both P-sites concurrently, enabling the accelerated synthesis of tri-BCPs in a one-pot, two-step procedure. The results from mechanistic studies, including the single crystal structure of the dually initiated active species, detailed polymerizations, and kinetic studies confirm the livingness of the polymerization and support the proposed polymerization mechanism featuring the dual initiation and subsequent chain growth from both P-sites of the superbase di-initiator.


Assuntos
4-Butirolactona/análogos & derivados , Elastômeros/química , Ácidos de Lewis/química , Fosfinas/química , Polímeros/química , 4-Butirolactona/química , Resinas Acrílicas/síntese química , Resinas Acrílicas/química , Cristalografia por Raios X , Elastômeros/síntese química , Cinética , Modelos Químicos , Estrutura Molecular , Polimerização , Polímeros/síntese química , Temperatura
8.
Nat Commun ; 12(1): 4924, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34389709

RESUMO

C-Glycosyl peptides/proteins are metabolically stable mimics of the native glycopeptides/proteins bearing O/N-glycosidic linkages, and are thus of great therapeutical potential. Herein, we disclose a protocol for the syntheses of vinyl C-glycosyl amino acids and peptides, employing a nickel-catalyzed reductive hydroglycosylation reaction of alkyne derivatives of amino acids and peptides with common glycosyl bromides. It accommodates a wide scope of the coupling partners, including complex oligosaccharide and peptide substrates. The resultant vinyl C-glycosyl amino acids and peptides, which bear common O/N-protecting groups, are amenable to further transformations, including elongation of the peptide and saccharide chains.


Assuntos
Alcinos/química , Aminoácidos/química , Glicosídeos/química , Níquel/química , Peptídeos/química , Brometos/química , Sequência de Carboidratos , Catálise , Dissacarídeos/química , Glicopeptídeos/síntese química , Glicopeptídeos/química , Glicosídeos/síntese química , Glicosilação , Modelos Químicos , Estrutura Molecular , Monossacarídeos/química , Oxirredução
9.
Chem Biol Interact ; 347: 109618, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34364836

RESUMO

The toxicity of hybrid nanoparticles, consisting of non-toxic components, zirconium dioxide nanoparticles (ZrO2 NPs), and caffeic acid (CA), was examined against four different cell lines (HTR-8 SV/Neo, JEG-3, JAR, and HeLa). Stable aqueous ZrO2 sol, synthesized by forced hydrolysis, consists of 3-4 nm in size primary particles organized in 30-60 nm in size snowflake-like particles, as determined by transmission electron microscopy and direct light scattering measurements. The surface modification of ZrO2 NPs with CA leads to the formation of an interfacial charge transfer (ICT) complex followed by the appearance of absorption in the visible spectral range. The spectroscopic observations are complemented with the density functional theory calculations using a cluster model. The ZrO2 NPs and CA are non-toxic against four different cell lines in investigated concentration range. Also, ZrO2 NPs promote the proliferation of HTR-8 SV/Neo, JAR, and HeLa cells. On the other hand, hybrid ZrO2/CA NPs induced a significant reduction of the viability of the JEG-3 cells (39 %) for the high concentration of components (1.6 mM ZrO2 and 0.4 mM CA).


Assuntos
Ácidos Cafeicos/toxicidade , Nanopartículas Metálicas/toxicidade , Placenta/efeitos dos fármacos , Zircônio/toxicidade , Ácidos Cafeicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Teoria da Densidade Funcional , Feminino , Humanos , Nanopartículas Metálicas/química , Modelos Químicos , Tamanho da Partícula , Placenta/patologia , Gravidez , Testes de Toxicidade , Zircônio/química
10.
PLoS Comput Biol ; 17(8): e1009284, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34347784

RESUMO

Modeling the impact of amino acid mutations on protein-protein interaction plays a crucial role in protein engineering and drug design. In this study, we develop GeoPPI, a novel structure-based deep-learning framework to predict the change of binding affinity upon mutations. Based on the three-dimensional structure of a protein, GeoPPI first learns a geometric representation that encodes topology features of the protein structure via a self-supervised learning scheme. These representations are then used as features for training gradient-boosting trees to predict the changes of protein-protein binding affinity upon mutations. We find that GeoPPI is able to learn meaningful features that characterize interactions between atoms in protein structures. In addition, through extensive experiments, we show that GeoPPI achieves new state-of-the-art performance in predicting the binding affinity changes upon both single- and multi-point mutations on six benchmark datasets. Moreover, we show that GeoPPI can accurately estimate the difference of binding affinities between a few recently identified SARS-CoV-2 antibodies and the receptor-binding domain (RBD) of the S protein. These results demonstrate the potential of GeoPPI as a powerful and useful computational tool in protein design and engineering. Our code and datasets are available at: https://github.com/Liuxg16/GeoPPI.


Assuntos
Substituição de Aminoácidos , Modelos Químicos , Proteínas/metabolismo , Mutação Puntual , Ligação Proteica , Proteínas/química , Proteínas/genética
11.
Phys Rev Lett ; 127(1): 014304, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34270281

RESUMO

We study experimentally and theoretically the phenomenon of "persistent response" in ultrastrongly driven membrane resonators. The term persistent response denotes the development of a vibrating state with nearly constant amplitude over an extreme wide frequency range. We reveal the underlying mechanism by directly imaging the vibrational state using advanced optical interferometry. We argue that this state is related to the nonlinear interaction between higher-order flexural modes and higher-order overtones of the driven mode. Finally, we propose a stability diagram for the different vibrational states that the membrane can adopt.


Assuntos
Membranas/química , Modelos Químicos , Interferometria , Dinâmica não Linear , Vibração
12.
Phys Rev Lett ; 127(1): 018301, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34270310

RESUMO

For two molecules to react they first have to meet. Yet, reaction times are rarely on par with the first-passage times that govern such molecular encounters. A prime reason for this discrepancy is stochastic transitions between reactive and nonreactive molecular states, which results in effective gating of product formation and altered reaction kinetics. To better understand this phenomenon we develop a unifying approach to gated reactions on networks. We first show that the mean and distribution of the gated reaction time can always be expressed in terms of ungated first-passage and return times. This relation between gated and ungated kinetics is then explored to reveal universal features of gated reactions. The latter are exemplified using a diverse set of case studies which are also used to expose the exotic kinetics that arises due to molecular gating.


Assuntos
Modelos Químicos , Difusão , Cinética
13.
Phys Rev Lett ; 127(1): 018003, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34270312

RESUMO

Within simulations of molecules deposited on a surface we show that neuroevolutionary learning can design particles and time-dependent protocols to promote self-assembly, without input from physical concepts such as thermal equilibrium or mechanical stability and without prior knowledge of candidate or competing structures. The learning algorithm is capable of both directed and exploratory design: it can assemble a material with a user-defined property, or search for novelty in the space of specified order parameters. In the latter mode it explores the space of what can be made, rather than the space of structures that are low in energy but not necessarily kinetically accessible.


Assuntos
Aprendizado de Máquina , Modelos Químicos , Método de Monte Carlo , Redes Neurais de Computação , Propriedades de Superfície
14.
Phys Rev Lett ; 126(25): 258101, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34241502

RESUMO

Biomolecular condensates self-assemble when proteins and nucleic acids spontaneously demix to form droplets within the crowded intracellular milieu. This simple mechanism underlies the formation of a wide variety of membraneless compartments in living cells. To understand how multiple condensates with distinct compositions can self-assemble in such a heterogeneous system, which may not be at thermodynamic equilibrium, we study a minimal model in which we can "program" the pairwise interactions among hundreds of species. We show that the number of distinct condensates that can be reliably assembled grows superlinearly with the number of species in the mixture when the condensates share components. Furthermore, we show that we can predict the maximum number of distinct condensates in a mixture without knowing the details of the pairwise interactions. Simulations of condensate growth confirm these predictions and suggest that the physical rules governing the achievable complexity of condensate-mediated spatial organization are broadly applicable to biomolecular mixtures.


Assuntos
Modelos Químicos , Ácidos Nucleicos/química , Proteínas/química
15.
Phys Rev Lett ; 126(25): 258102, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34241518

RESUMO

Liquid-liquid phase separation is a fundamental mechanism underlying subcellular organization. Motivated by the striking observation that optogenetically generated droplets in the nucleus display suppressed coarsening dynamics, we study the impact of chromatin mechanics on droplet phase separation. We combine theory and simulation to show that cross-linked chromatin can mechanically suppress droplets' coalescence and ripening, as well as quantitatively control their number, size, and placement. Our results highlight the role of the subcellular mechanical environment on condensate regulation.


Assuntos
Núcleo Celular/química , Cromatina/química , Modelos Químicos , Fenômenos Biomecânicos , Linhagem Celular Tumoral , Humanos , Transição de Fase , Propriedades de Superfície , Termodinâmica
16.
Phys Rev Lett ; 127(2): 028001, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34296930

RESUMO

The compression of soft elastic matter and biological tissue can lead to creasing, an instability where a surface folds sharply into periodic self-contacts. Intriguingly, the unfolding of the surface upon releasing the strain is usually not perfect: small scars remain that serve as nuclei for creases during repeated compressions. Here we present creasing experiments with sticky polymer surfaces, using confocal microscopy, which resolve the contact line region where folding and unfolding occurs. It is found that surface tension induces a second fold, at the edge of the self-contact, which leads to a singular elastic stress and self-similar crease morphologies. However, these profiles exhibit an intrinsic folding-unfolding asymmetry that is caused by contact line pinning, in a way that resembles wetting of liquids on imperfect solids. Contact line pinning is therefore a key element of creasing: it inhibits complete unfolding and gives soft surfaces a folding memory.


Assuntos
Modelos Químicos , Polímeros/química , Módulo de Elasticidade , Elasticidade , Microscopia Confocal , Tensão Superficial
17.
Phys Rev Lett ; 127(2): 028101, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34296898

RESUMO

DNA torsional elastic properties play a crucial role in DNA structure, topology, and the regulation of motor protein progression. However, direct measurements of these parameters are experimentally challenging. Here, we present a constant-extension method integrated into an angular optical trap to directly measure torque during DNA supercoiling. We measured the twist persistence length of extended DNA to be 22 nm under an extremely low force (∼0.02 pN) and the twist persistence length of plectonemic DNA to be 24 nm. In addition, we implemented a rigorous data analysis scheme that bridged our measurements with existing theoretical models of DNA torsional behavior. This comprehensive set of torsional parameters demonstrates that at least 20% of DNA supercoiling is partitioned into twist for both extended DNA and plectonemic DNA. This work provides a new experimental methodology, as well as an analytical and interpretational framework, which will enable, expand, and enhance future studies of DNA torsional properties.


Assuntos
DNA Super-Helicoidal/química , DNA/química , Elasticidade , Modelos Químicos , Conformação de Ácido Nucleico , Termodinâmica
18.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299196

RESUMO

The phenomenon of drag reduction (known as the "Toms effect") has many industrial and engineering applications, but a definitive molecular-level theory has not yet been constructed. This is due both to the multiscale nature of complex fluids and to the difficulty of directly observing self-assembled structures in nonequilibrium states. On the basis of a large-scale coarse-grained molecular simulation that we conducted, we propose a possible mechanism of turbulence suppression in surfactant aqueous solution. We demonstrate that maintaining sufficiently large micellar structures and a homogeneous radial distribution of surfactant molecules is necessary to obtain the drag-reduction effect. This is the first molecular-simulation evidence that a micellar structure is responsible for drag reduction in pipe flow, and should help in understanding the mechanisms underlying drag reduction by surfactant molecules under nonequilibrium conditions.


Assuntos
Tensoativos/química , Água/química , Simulação por Computador , Fricção , Micelas , Modelos Químicos , Simulação de Dinâmica Molecular , Fenômenos Físicos , Viscosidade
19.
Nat Commun ; 12(1): 4518, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312393

RESUMO

Multiplexed optical imaging provides holistic visualization on a vast number of molecular targets, which has become increasingly essential for understanding complex biological processes and interactions. Vibrational microscopy has great potential owing to the sharp linewidth of vibrational spectra. In 2017, we demonstrated the coupling between electronic pre-resonant stimulated Raman scattering (epr-SRS) microscopy with a proposed library of 9-cyanopyronin-based dyes, named Manhattan Raman Scattering (MARS). Herein, we develop robust synthetic methodology to build MARS probes with different core atoms, expansion ring numbers, and stable isotope substitutions. We discover a predictive model to correlate their vibrational frequencies with structures, which guides rational design of MARS dyes with desirable Raman shifts. An expanded library of MARS probes with diverse functionalities is constructed. When coupled with epr-SRS microscopy, these MARS probes allow us to demonstrate not only many versatile labeling modalities but also increased multiplexing capacity. Hence, this work opens up next-generation vibrational imaging with greater utilities.


Assuntos
Corantes/química , Sondas Moleculares/química , Microscopia Óptica não Linear/métodos , Imagem Óptica/métodos , Pironina/química , Corantes/síntese química , Células HeLa , Humanos , Modelos Químicos , Sondas Moleculares/síntese química , Estrutura Molecular , Pironina/análogos & derivados , Pironina/síntese química , Análise Espectral Raman/métodos , Vibração
20.
Nat Commun ; 12(1): 4534, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312395

RESUMO

Benzene is a widely used commodity chemical, which is currently produced from fossil resources. Lignin, a waste from lignocellulosic biomass industry, is the most abundant renewable source of benzene ring in nature. Efficient production of benzene from lignin, which requires total transformation of Csp2-Csp3/Csp2-O into C-H bonds without side hydrogenation, is of great importance, but has not been realized. Here, we report that high-silica HY zeolite supported RuW alloy catalyst enables in situ refining of lignin, exclusively to benzene via coupling Bronsted acid catalyzed transformation of the Csp2-Csp3 bonds on the local structure of lignin molecule and RuW catalyzed hydrogenolysis of the Csp2-O bonds using the locally abstracted hydrogen from lignin molecule, affording a benzene yield of 18.8% on lignin weight basis in water system. The reaction mechanism is elucidated in detail by combination of control experiments and density functional theory calculations. The high-performance protocol can be readily scaled up to produce 8.5 g of benzene product from 50.0 g lignin without any saturation byproducts. This work opens the way to produce benzene using lignin as the feedstock efficiently.


Assuntos
Benzeno/química , Hidrogênio/química , Lignina/química , Água/química , Zeolitas/química , Benzeno/síntese química , Catálise , Ligação de Hidrogênio , Nanopartículas Metálicas/química , Metais/química , Modelos Químicos , Estrutura Molecular , Oxirredução
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...