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1.
Science ; 380(6650): 1165-1168, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37319215

RESUMO

Reaction-rate modifications for chemical processes due to strong coupling between reactant molecular vibrations and the cavity vacuum have been reported; however, no currently accepted mechanisms explain these observations. In this work, reaction-rate constants were extracted from evolving cavity transmission spectra, revealing resonant suppression of the intracavity reaction rate for alcoholysis of phenyl isocyanate with cyclohexanol. We observed up to an 80% suppression of the rate by tuning cavity modes to be resonant with the reactant isocyanate (NCO) stretch, the product carbonyl (CO) stretch, and cooperative reactant-solvent modes (CH). These results were interpreted using an open quantum system model that predicted resonant modifications of the vibrational distribution of reactants from canonical statistics as a result of light-matter quantum coherences, suggesting links to explore between chemistry and quantum science.

2.
Proc Natl Acad Sci U S A ; 120(20): e2220852120, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155895

RESUMO

Many photonic and electronic molecular properties, as well as chemical and biochemical reactivities are controlled by fast intramolecular vibrational energy redistribution (IVR). This fundamental ultrafast process limits coherence time in applications from photochemistry to single quantum level control. While time-resolved multidimensional IR-spectroscopy can resolve the underlying vibrational interaction dynamics, as a nonlinear optical technique it has been challenging to extend its sensitivity to probe small molecular ensembles, achieve nanoscale spatial resolution, and control intramolecular dynamics. Here, we demonstrate a concept how mode-selective coupling of vibrational resonances to IR nanoantennas can reveal intramolecular vibrational energy transfer. In time-resolved infrared vibrational nanospectroscopy, we measure the Purcell-enhanced decrease of vibrational lifetimes of molecular vibrations while tuning the IR nanoantenna across coupled vibrations. At the example of a Re-carbonyl complex monolayer, we derive an IVR rate of (25±8) cm-1 corresponding to (450±150) fs, as is typical for the fast initial equilibration between symmetric and antisymmetric carbonyl vibrations. We model the enhancement of the cross-vibrational relaxation based on intrinsic intramolecular coupling and extrinsic antenna-enhanced vibrational energy relaxation. The model further suggests an anti-Purcell effect based on antenna and laser-field-driven vibrational mode interference which can counteract IVR-induced relaxation. Nanooptical spectroscopy of antenna-coupled vibrational dynamics thus provides for an approach to probe intramolecular vibrational dynamics with a perspective for vibrational coherent control of small molecular ensembles.

3.
Artigo em Inglês | MEDLINE | ID: mdl-36981880

RESUMO

Accessibility to housing is crucial for people with disabilities as it provides them with equal opportunities and allows them to live independently. A systematic literature review has been conducted to understand the current research on accessibility in housing for people with disabilities in Latin America. The study analysed 56 papers and used co-word analysis to identify common themes and topics within the documents. The results of the analysis showed that Brazil (61%) is the country with the most research on the subject, physical disability, at 36%, is the impairment most analysed, and interventions or analysis for the older people (45%) in their homes is the most researched type of population. The co-word analysis revealed that topics such as policy, regulations, the use of technologies, ergonomics interventions, and architectural criteria or barriers to the daily life of disabled people were frequently discussed in the papers. Although this work shows a substantial and growing increase in research on housing for people with disabilities in Latin America, it also demonstrates the importance of increasing research on other types of impairment, such as visual and cognitive-intellectual disabilities, and including children, caregivers, or even young adults.


Assuntos
Pessoas com Deficiência , Deficiência Intelectual , Criança , Adulto Jovem , Humanos , Idoso , Habitação , América Latina , Políticas
4.
J Phys Chem A ; 127(10): 2407-2414, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36876889

RESUMO

Identifying chemical compounds is essential in several areas of science and engineering. Laser-based techniques are promising for autonomous compound detection because the optical response of materials encodes enough electronic and vibrational information for remote chemical identification. This has been exploited using the fingerprint region of infrared absorption spectra, which involves a dense set of absorption peaks that are unique to individual molecules, thus facilitating chemical identification. However, optical identification using visible light has not been realized. Using decades of experimental refractive index data in the scientific literature of pure organic compounds and polymers over a broad range of frequencies from the ultraviolet to the far-infrared, we develop a machine learning classifier that can accurately identify organic species based on a single-wavelength dispersive measurement in the visible spectral region, away from absorption resonances. The optical classifier proposed here could be applied to autonomous material identification protocols and applications.

5.
Pensar mov ; 20(2)dic. 2022.
Artigo em Espanhol | LILACS, SaludCR | ID: biblio-1422230

RESUMO

Cornejo, M. I., Henríquez, M., Herrera, F., Muñoz, F., Bernardes, N., Auricchio, J. R., y Castelli-Correia de Campos, L. F. (2022). Percepción de la calidad de vida en para- deportistas y no deportistas chilenos con lesión cerebral. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20 (2), 1-18. La calidad de vida (CV) y la actividad física son aspectos relevantes en la salud de la población, y esta última con un impacto positivo en las personas con discapacidad. Debido a esto, los objetivos de este estudio fueron comparar las características e identificar la asociación entre los dominios de la percepción de la CV entre un grupo de personas con lesión cerebral que practican fútbol, para-deportistas (PD) y personas con lesión cerebral no para-deportistas (NPD), además determinar si existen diferencias en la percepción de la CV según las diferentes clases deportivas (FT1, FT2 y FT3). El estudio se desarrolló en Chile, donde se aplicó el cuestionario WHOQOL-BREF para determinar la CV de los participantes. Los resultados identificaron una relación positiva y significativa entre los distintos dominios de la CV (p < .001, r = .44 - .67). Además, se observó una mejor percepción de la CV en los PD (p < .001, TE = 1.18, grande) en comparación con lo reportado por el grupo NPD. Por otro lado, no se obtuvieron diferencias significativas entre los dominios para las diferentes clases deportivas en el grupo PD. Estos datos refuerzan la idea de que la práctica deportiva influye en la participación social y en la percepción de la CV en PD con lesión cerebral. El desarrollo conjunto de los factores asociados entre la salud y el bienestar socioemocional podrían colaborar con la consolidación de la práctica deportiva y de actividad física, los cuales, a su vez son beneficiosos para las personas con discapacidad tal como lo plantean los objetivos del desarrollo sostenible en su agenda de trabajo provista al año 2030.


Cornejo, M. I., Henríquez, M., Herrera, F., Muñoz, F., Bernardes, N., Auricchio, J. R., y Castelli-Correia de Campos, L. F. (2022). Perception of quality of life in chilean para-athletes and non-athletes with brain injury. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20 (2), 1-16. Quality of life (QOL) and physical activity are relevant aspects in the health of the population, and the latter has a positive impact on people with disabilities. For this reason, the objectives of this study were to compare the characteristics and identify the association between the domains of QOL perception between a group of people with brain injury who practice soccer, para-athletes (PD) and non-para-athletes with brain injury (NPD), as well as to determine if there are differences in the perception of QOL according to the different sports classes (FT1, FT2 and FT3). The study was carried out in Chile, where the WHOQOL-BREF questionnaire was applied to determine the QOL of participants. The results identified a positive and significant relationship between the different domains of QOL (p < .001, r = .44 - .67). In addition, a better perception of QoL was observed in the PDs (p < .001, TE = 1.18, large) compared to that reported by the NPD group. On the other hand, no significant differences between domains were obtained for the different sport classes in the PD group. These data reinforce the idea that sport practice influences social participation and perception of QoL in PD with brain injury. The joint development of the factors associated between health and socioemotional well-being could collaborate in the consolidation of sports practice and physical activity, which, in turn, are beneficial for people with disabilities, as proposed by the Sustainable Development Goals in their work agenda foreseen for the year 2030.


Cornejo, M. I., Henríquez, M., Herrera, F., Muñoz, F., Bernardes, N., Auricchio, J. R., y Castelli-Correia de Campos, L. F. (2022). Percepção da qualidade de vida em paratletas e não-atletas chilenos com lesões cerebrais. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20 (2), 1-16. Qualidade de vida (QV) e atividade física são aspectos relevantes da saúde da população, tendo esta última um impacto positivo sobre as pessoas com deficiências. Portanto, os objetivos deste estudo foram comparar as características e identificar a associação entre os domínios da percepção de QV entre um grupo de pessoas com lesões cerebrais que praticam futebol, paratletas (P) e pessoas com lesões cerebrais não paratletas (NP), e determinar se existem diferenças na percepção de QV de acordo com as diferentes classes esportivas (FT1, FT2 e FT3). O estudo foi realizado no Chile, onde o questionário WHOQOL-BREF foi utilizado para determinar o QV dos participantes. Os resultados identificaram uma relação positiva e significativa entre os diferentes domínios da QV (p < 0,001, r = 0,44 - 0,67). Além disso, uma melhor percepção de QV foi observada nos Ps (p < 0,001, TE = 1,18, grande) em comparação com a relatada pelo grupo NP. Por outro lado, não foram obtidas diferenças significativas entre os domínios para as diferentes classes esportivas do grupo P. Estes dados reforçam a ideia de que a prática esportiva influencia a participação social e a percepção da QV nos P com lesão cerebral. O desenvolvimento conjunto de fatores associados à saúde e ao bem-estar socioemocional poderia contribuir para a consolidação da prática do esporte e da atividade física, que, por sua vez, são benéficos para as pessoas com deficiência, conforme estabelecido nas Metas de Desenvolvimento Sustentável em sua agenda para 2030.


Assuntos
Humanos , Masculino , Adulto , Qualidade de Vida , Futebol , Paralisia Cerebral , Chile , Deficiência Intelectual
6.
J Chem Phys ; 157(19): 194104, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36414439

RESUMO

Modeling the non-equilibrium dissipative dynamics of strongly interacting quantized degrees of freedom is a fundamental problem in several branches of physics and chemistry. We implement a quantum state trajectory scheme for solving Lindblad quantum master equations that describe coherent and dissipative processes for a set of strongly coupled quantized oscillators. The scheme involves a sequence of stochastic quantum jumps with transition probabilities determined by the system state and the system-reservoir dynamics. Between consecutive jumps, the wave function is propagated in a coordinate space using the multi-configuration time-dependent Hartree method. We compare this hybrid propagation methodology with exact Liouville space solutions for physical systems of interest in cavity quantum electrodynamics, demonstrating accurate results for experimentally relevant observables using a tractable number of quantum trajectories. We show the potential for solving the dissipative dynamics of finite size arrays of strongly interacting quantized oscillators with high excitation densities, a scenario that is challenging for conventional density matrix propagators due to the large dimensionality of the underlying Hilbert space.

7.
ACS Omega ; 7(28): 24432-24437, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35874204

RESUMO

Metal-organic frameworks (MOFs) have emerged as promising tailor-designed materials for developing next-generation solid-state devices with applications in linear and nonlinear coherent optics. However, the implementation of functional devices is challenged by the notoriously difficult process of growing large MOF single crystals of high optical quality. By controlling the solvothermal synthesis conditions, we succeeded in producing large individual single crystals of the noncentrosymmetric MOF Zn(3-ptz)2 (MIRO-101) with a deformed octahedron habit and surface areas of up to 37 mm2. We measured the UV-vis absorption spectrum of individual Zn(3-ptz)2 single crystals across different lateral incidence planes. Millimeter-sized single crystals have a band gap of E g = 3.32 eV and exhibit anisotropic absorption in the band-edge region near 350 nm, whereas polycrystalline samples are fully transparent in the same frequency range. Using solid-state density functional theory (DFT), the observed size dependence in the optical anisotropy is correlated with the preferred orientation adopted by pyridyl groups under conditions of slow crystal self-assembly. Our work thus paves the way for the development of optical polarization switches based on metal-organic frameworks.

8.
Materials (Basel) ; 15(11)2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35683252

RESUMO

This article focuses on agar biopolymer films that offer promise for developing biodegradable packaging, an important solution for reducing plastics pollution. At present there is a lack of data on the mechanical performance of agar biopolymer films using a simple plasticizer. This study takes a Design of Experiments approach to analyze how agar-glycerin biopolymer films perform across a range of ingredients concentrations in terms of their strength, elasticity, and ductility. Our results demonstrate that by systematically varying the quantity of agar and glycerin, tensile properties can be achieved that are comparable to agar-based materials with more complex formulations. Not only does our study significantly broaden the amount of data available on the range of mechanical performance that can be achieved with simple agar biopolymer films, but the data can also be used to guide further optimization efforts that start with a basic formulation that performs well on certain property dimensions. We also find that select formulations have similar tensile properties to thermoplastic starch (TPS), acrylonitrile butadiene styrene (ABS), and polypropylene (PP), indicating potential suitability for select packaging applications. We use our experimental dataset to train a neural network regression model that predicts the Young's modulus, ultimate tensile strength, and elongation at break of agar biopolymer films given their composition. Our findings support the development of further data-driven design and fabrication workflows.

9.
J Chem Phys ; 156(12): 124110, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35364879

RESUMO

Nanoscale infrared (IR) resonators with sub-diffraction limited mode volumes and open geometries have emerged as new platforms for implementing cavity quantum electrodynamics at room temperature. The use of IR nanoantennas and tip nanoprobes to study strong light-matter coupling of molecular vibrations with the vacuum field can be exploited for IR quantum control with nanometer spatial and femtosecond temporal resolution. In order to advance the development of molecule-based quantum nanophotonics in the mid-IR, we propose a generally applicable semi-empirical methodology based on quantum optics to describe light-matter interaction in systems driven by mid-IR femtosecond laser pulses. The theory is shown to reproduce recent experiments on the acceleration of the vibrational relaxation rate in infrared nanostructures. It also provides physical insights on the implementation of coherent phase rotations of the near-field using broadband nanotips. We then apply the quantum framework to develop general tip-design rules for the experimental manipulation of vibrational strong coupling and Fano interference effects in open infrared resonators. We finally propose the possibility of transferring the natural anharmonicity of molecular vibrational levels to the resonator near-field in the weak coupling regime to implement intensity-dependent phase shifts of the coupled system response with strong pulses and develop a vibrational chirping model to understand the effect. The semi-empirical quantum theory is equivalent to first-principles techniques based on Maxwell's equations, but its lower computational cost suggests its use as a rapid design tool for the development of strongly coupled infrared nanophotonic hardware for applications ranging from quantum control of materials to quantum information processing.

10.
J Chem Phys ; 156(11): 114702, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35317564

RESUMO

We propose to use molecular picocavity ensembles as macroscopic coherent nonlinear optical devices enabled by nanoscale strong coupling. For a generic picocavity model that includes molecular and photonic disorder, we derive theoretical performance bounds for coherent cross-phase modulation signals using weak classical fields of different frequencies. We show that strong coupling of the picocavity vacua with a specific vibronic sideband in the molecular emission spectrum results in a significant variation of the effective refractive index of the metamaterial relative to a molecule-free scenario due to a vacuum-induced Autler-Townes effect. For a realistic molecular disorder model, we demonstrate that cross-phase modulation of optical fields as weak as 10 kW/cm2 is feasible using dilute ensembles of molecular picocavities at room temperature, provided that the confined vacuum is not resonantly driven by the external probe field. Our work paves the way for the development of plasmonic metamaterials that exploit strong coupling for optical state preparation and quantum control.

11.
ACS Omega ; 6(27): 17289-17298, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34278115

RESUMO

The solvothermal synthesis of metal-organic frameworks (MOFs) often proceeds through competing crystallization pathways, and only partial control over the crystal nucleation and growth rates is possible. It challenges the use of MOFs as functional devices in free-space optics, where bulk single crystals of millimeter dimensions and high optical quality are needed. We develop a synthetic protocol to control the solvothermal growth of the MOF [Zn(3-ptz)2] n (MIRO-101), to obtain large single crystals with projected surface areas of up to 25 mm2 in 24 h, in a single reaction with in situ ligand formation. No additional cooling and growth steps are necessary. We propose a viable reaction mechanism for the formation of MIRO-101 crystals under acidic conditions, by isolating intermediate crystal structures that directly connect with the target MOF and reversibly interconverting between them. We also study the nucleation and growth kinetics of MIRO-101 using ex situ crystal image analysis. The synthesis parameters that control the size and morphology of our target MOF crystal are discussed. Our work deepens our understanding of MOF growth processes in solution and demonstrates the possibility of building MOF-based devices for future applications in optics.

12.
Chem Sci ; 12(10): 3475-3482, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-34163620

RESUMO

The discovery and design of new materials with competitive optical frequency conversion efficiencies can accelerate the development of scalable photonic quantum technologies. Metal-organic framework (MOF) crystals without inversion symmetry have shown potential for these applications, given their nonlinear optical properties and the combinatorial number of possibilities for MOF self-assembly. In order to accelerate the discovery of MOF materials for quantum optical technologies, scalable computational assessment tools are needed. We develop a multi-scale methodology to study the wavefunction of entangled photon pairs generated by selected non-centrosymmetric MOF crystals via spontaneous parametric down-conversion (SPDC). Starting from an optimized crystal structure, we predict the shape of the G (2) intensity correlation function for coincidence detection of the entangled pairs, produced under conditions of collinear type-I phase matching. The effective nonlinearities and photon pair correlation times obtained are comparable to those available with inorganic crystal standards. Our work thus provides fundamental insights into the structure-property relationships for entangled photon generation with metal-organic frameworks, paving the way for the automated discovery of molecular materials for optical quantum technology.

13.
Am J Case Rep ; 22: e928420, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34111056

RESUMO

BACKGROUND Pesticides are commonly used in the agricultural industry. Overdose can be lethal due to its effects generating closure of the voltage-gated sodium channels in the axonal membranes. Most case reports of toxicity refer to skin exposure and there are very few that refer to effects due to its oral intake. CASE REPORT We report the case of an elderly woman with Alzheimer disease who accidentally swallowed 50 g of Lambda Cyhalothrin (GOLPE 5 M E®), a pyrethroid of medium toxicity containing a cyano group. It severely harmed the woman's health, causing severe central nervous system depression and refractory vasodilated shock requiring the use of vasopressors. Its management was challenging, requiring orotracheal intubation, vasopressors, and admission to the Intensive Care Unit (ICU). The emergency care team decided to use intravenous lipid emulsion, which clearly helped with the recovery and successful discharge of the patient. CONCLUSIONS The use of intravenous lipid emulsion for the treatment of pyrethroid poisoning can lead to successful outcomes, as described in this case report.


Assuntos
Doença de Alzheimer , Overdose de Drogas , Praguicidas , Piretrinas , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/tratamento farmacológico , Overdose de Drogas/tratamento farmacológico , Emulsões Gordurosas Intravenosas/uso terapêutico , Feminino , Humanos , Piretrinas/uso terapêutico
14.
Adapt Phys Activ Q ; 38(2): 232-247, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33596537

RESUMO

This study compared physical performance in a group of international cerebral palsy football players during two formats of small-sided games (SSGs) and performance in a simulated game (SG) according to players' sport classes (FT1, FT2, and FT3). Internal load (heart rate and rating of perceived exertion) and external load (total distance, distance covered at different velocities, maximum speed reached, acceleration, and deceleration) were obtained with global positioning system devices during two formats of SSGs (2-a-side/SSG2 and 4-a-side/SSG4) and an SG (7-a-side). SSG2 demands faster actions compared with SSG4/SG, and significant differences and large effect sizes were found in the distance covered in Speed Zones 5 (16.0-17.9 km/hr) and 6 (>18.0 km/hr; p < .05; .35<ηp2<.50, large). Lower moderate accelerations and decelerations per minute in SSG4/SG compared with SSG2 were also found (p < .01; .77<ηp2<.81, large). In the SSG2 task, the FT3 players reached maximum speeds, covered more distance at the highest intensities, and performed more moderate/high accelerations/decelerations and more sprints compared with FT1 and FT2 players (p < .05; -0.85 < dg < -4.64, large). The SSG2 task could be the best option for discriminating physical demands in important variables for cerebral palsy football performance between classes FT3 versus FT1/FT2.


Assuntos
Desempenho Atlético , Paralisia Cerebral , Futebol , Aceleração , Humanos , Esforço Físico
15.
Nat Commun ; 12(1): 214, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431901

RESUMO

Strong cavity coupling to molecular vibrations creates vibration-polaritons capable of modifying chemical reaction kinetics, product branching ratios, and charge transfer equilibria. However, the mechanisms impacting these molecular processes remain elusive. Furthermore, even basic elements determining the spectral properties of polaritons, such as selection rules, transition moments, and lifetimes are poorly understood. Here, we use two-dimensional infrared and filtered pump-probe spectroscopy to report clear spectroscopic signatures and relaxation dynamics of excited vibration-polaritons formed from the cavity-coupled NO band of nitroprusside. We apply an extended multi-level quantum Rabi model that predicts transition frequencies and strengths that agree well with our experiment. Notably, the polariton features decay ~3-4 times slower than the polariton dephasing time, indicating that they support incoherent population, a consequence of their partial matter character.

16.
J Chem Phys ; 152(23): 234111, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32571050

RESUMO

Vibrational strong coupling has emerged as a promising route for manipulating the reactivity of molecules inside infrared cavities. We develop a full-quantum methodology to study the unitary dynamics of a single anharmonic vibrational mode interacting with a quantized infrared cavity field. By comparing multi-configurational time-dependent Hartree simulations for an intracavity Morse oscillator with an equivalent formulation of the problem in Hilbert space, we describe for the first time the essential role of permanent dipole moments in the femtosecond dynamics of vibrational polariton wavepackets. We classify molecules into three general families according to the shape of their electric dipole function de(q) along the vibrational mode coordinate q. For polar species with a positive slope of the dipole function at equilibrium, an initial diabatic light-matter product state without vibrational or cavity excitations evolves into a polariton wavepacket with a large number of intracavity photons for interaction strengths at the conventional onset of ultrastrong coupling. This buildup of the cavity photon amplitude is accompanied by an effective lengthening of the vibrational mode that is comparable with a laser-induced vibrational excitation in free space. In contrast, polar molecules with a negative slope of the dipole function experience an effective mode shortening, under equivalent coupling conditions. We validate our predictions using realistic ab initio ground state potentials and dipole functions for HF and CO2 molecules. We also propose a non-adiabatic state preparation scheme to generate vibrational polaritons with molecules near infrared nanoantennas for the spontaneous radiation of infrared quantum light.

17.
J Chem Phys ; 152(10): 100902, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171209

RESUMO

This is a tutorial-style introduction to the field of molecular polaritons. We describe the basic physical principles and consequences of strong light-matter coupling common to molecular ensembles embedded in UV-visible or infrared cavities. Using a microscopic quantum electrodynamics formulation, we discuss the competition between the collective cooperative dipolar response of a molecular ensemble and local dynamical processes that molecules typically undergo, including chemical reactions. We highlight some of the observable consequences of this competition between local and collective effects in linear transmission spectroscopy, including the formal equivalence between quantum mechanical theory and the classical transfer matrix method, under specific conditions of molecular density and indistinguishability. We also overview recent experimental and theoretical developments on strong and ultrastrong coupling with electronic and vibrational transitions, with a special focus on cavity-modified chemistry and infrared spectroscopy under vibrational strong coupling. We finally suggest several opportunities for further studies that may lead to novel applications in chemical and electromagnetic sensing, energy conversion, optoelectronics, quantum control, and quantum technology.

18.
J Chem Phys ; 151(14): 144116, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31615252

RESUMO

We propose a cavity QED approach to describe light-matter interaction of an infrared cavity field with an anharmonic vibration of a single nonpolar molecule. Starting from a generic Morse oscillator potential with quantized nuclear motion, we derive a multilevel quantum Rabi model to study vibrational polaritons beyond the rotating-wave approximation. We analyze the spectrum of vibrational polaritons in detail and compare it with available experiments. For high excitation energies, the system exhibits a dense manifold of polariton level crossings and avoided crossings as the light-matter coupling strength and cavity frequency are tuned. We also analyze polariton eigenstates in nuclear coordinate space. We show that the bond length of a vibrational polariton at a given energy is never greater than the bond length of a Morse oscillator with the same energy. This type of polariton bond strengthening occurs at the expense of the creation of virtual infrared cavity photons and may have implications in chemical reactivity of polariton states.

19.
ACS Omega ; 4(11): 14398-14403, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31528792

RESUMO

We describe the structure and properties of [Zn(C6H4N5)N3] n , a new nonporous three-dimensional high-energy metal-organic framework (HE-MOF) with enhanced thermal stability. The compound is synthesized by the hydrothermal method with in situ ligand formation under controlled pH and characterized using single-crystal X-ray diffraction, elemental analysis, and Fourier transform infrared. The measured detonation temperature (T det = 345 °C) and heat of detonation (ΔH det = -0.380 kcal/g) compare well with commercial explosives and other nitrogen-rich HE-MOFs. The velocity and pressure of denotation are 5.96 km/s and 9.56 GPa, respectively. Differential scanning calorimetry analysis shows that the denotation of [Zn(C6H4N5)N3] n occurs via a complex temperature-dependent mechanism.

20.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 6): 867-871, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31391984

RESUMO

The title compound, [Ni(C10H8N2)3](C9H5N4O)2·2H2O, crystallizes as a racemic mixture in the monoclinic space group C2/c. In the crystal, the 1,1,3,3-tetracyano-2-ethoxypropenide anions and the water molecules are linked by O-H⋯N hydrogen bonds, forming chains running along the [010] direction. The bpy ligands of the cation are linked to the chain via C-H⋯π(cation) inter-actions involving the CH3 group. The inter-molecular inter-actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots.

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