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Item type:Publication, Coherence in chemistry: Foundations and frontiers(American Chemical Society, 2024-11-13)Coherence refers to correlations in waves. Because matter has a wave-particle nature, it is unsurprising that coherence has deep connections with the most contemporary issues in chemistry research (e.g., energy harvesting, femtosecond spectroscopy, molecular qubits and more). But what does the word “coherence” really mean in the context of molecules and other quantum systems? We provide a review of key concepts, definitions, and methodologies, surrounding coherence phenomena in chemistry, and we describe how the terms “coherence” and “quantum coherence” refer to many different phenomena in chemistry. Moreover, we show how these notions are related to the concept of an interference pattern. Coherence phenomena are indeed complex, and ambiguous definitions may spawn confusion. By describing the many definitions and contexts for coherence in the molecular sciences, we aim to enhance understanding and communication in this broad and active area of chemistry. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A DFT analysis for synthesizing vitamin A(American Chemical Society, 2024-11-25)Vitamin A deficiency (VAD) is a major nutritional concern in lower-income countries. It is responsible for thousands of deaths in those countries every year. Thus, finding the optimal route for vitamin A synthesis is essential, especially for the countries that are influenced by VAD. Three mechanisms of synthesizing Vitamin A have been evaluated by Density Functional Theory (DFT) calculations. This experiment investigated the BASF C15 + C5 Wittig approach, the Rhône-Poulenc C15 + C5 Julia approach, and the Kuraray C10 + C10 approach. The electronic energy, highest occupied molecular orbital energy, and dipole moments were calculated using the B3LYP functional and the 3-21g basis set. The energy profiles of these synthesis routes were compared to determine the most energetically favorable method. The Julia approach has the lowest energy change, indicating its higher efficiency in terms of energy compared to the Wittig and Kuraray methods. It is shown that other factors such as scalability and raw material availability should also be considered in industrial applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Seeking a quantum advantage with trapped-ion quantum simulations of condensed-phase chemical dynamics(Nature Research, 2024-05-01)Simulating the quantum dynamics of molecules in the condensed phase represents a longstanding challenge in chemistry. Trapped-ion quantum systems may serve as a platform for the analog-quantum simulation of chemical dynamics that is beyond the reach of current classical-digital simulation. To identify a ‘quantum advantage’ for these simulations, performance analysis of both analog-quantum simulation on noisy hardware and classical-digital algorithms is needed. In this Review, we make a comparison between a noisy analog trapped-ion simulator and a few choice classical-digital methods on simulating the dynamics of a model molecular Hamiltonian with linear vibronic coupling. We describe several simple Hamiltonians that are commonly used to model molecular systems, which can be simulated with existing or emerging trapped-ion hardware. These Hamiltonians may serve as stepping stones towards the use of trapped-ion simulators for systems beyond the reach of classical-digital methods. Finally, we identify dynamical regimes in which classical-digital simulations seem to have the weakest performance with respect to analog-quantum simulations. These regimes may provide the lowest hanging fruit to make the most of potential quantum advantages. (Figure presented.) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Seeking a Quantum Advantage with Trapped-Ion Quantum Simulations of Condensed-Phase Chemical Dynamics(Cornell University, 2023-05-04)Simulating the quantum dynamics of molecules in the condensed phase represents a longstanding challenge in chemistry. Trapped-ion quantum systems may serve as a platform for the analog-quantum simulation of chemical dynamics that is beyond the reach of current classical-digital simulation. To identify a 'quantum advantage' for these simulations, performance analysis of both analog-quantum simulation on noisy hardware and classical-digital algorithms is needed. In this Review, we make a comparison between a noisy analog trapped-ion simulator and a few choice classical-digital methods on simulating the dynamics of a model molecular Hamiltonian with linear vibronic coupling. We describe several simple Hamiltonians that are commonly used to model molecular systems, which can be simulated with existing or emerging trapped-ion hardware. These Hamiltonians may serve as stepping stones toward the use of trapped-ion simulators for systems beyond the reach of classical-digital methods. Finally, we identify dynamical regimes where classical-digital simulations seem to have the weakest performance compared to analog-quantum simulations. These regimes may provide the lowest hanging fruit to exploit potential quantum advantages. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ultrafast Electron Dynamics of a Ferrocene-Based Butadiyne-Bridged Complex(American Chemical Society, 2026-03-26)High Resolution Image Download MS PowerPoint Slide Photoinduced electron transfer (ET) in alkyne-linked donor–bridge–acceptor (DBA) compounds is strongly influenced by torsional flexibility, allowing control over ET without altering the donor–acceptor distance. Here, we investigate excited-state dynamics in Fc-C4-NAP, a DBA compound featuring a ferrocene (Fc) donor, a butadiyne bridge (C4), and a 1,8-naphthalimide (NAP) acceptor. Unlike analogues DBA compounds with fully organic planar donors, Fc-C4-NAP exhibits a complex excited-state manifold. Femtosecond transient absorption (TA) measurements in the visible and mid-IR regions found three characteristic relaxation times (0.3–0.5 ps, ∼2.6 ps, and 17–20 ps) following its excitation at 402 nm, which prepares NAP-centered excited states.TD-DFT computations indicate that the acceptor-based locally excited (LE) and the charge separated (CS) diabatic states are well coupled to the Fc states associated with d-states of Fe. This bridge-mediated coupling, estimated at 200–500 cm –1, is strong enough to induce significant mixing of the diabatic states, which also depends strongly on the torsional angle between the NAP and the C4-bonded cyclopentadienyl ring. The spectral changes observed in the TA experiments suggest that the fast component of 0.3–0.5 ps reflects the lifetime of the bright, dominantly NAP-centered state, which relaxes predominantly to the Fc-based states. The middle component of 2.6 ps could have multiple contributions, including relaxation of the nominal CS state, vibrational cooling, and solvation. The slow decay component of ca. 20 ps corresponds to the lifetime of the lowest-energy Fc states; two Fc states of similar energies but perpendicular polarizations. The complex nature of the eigenstates, unraveled by TD-DFT analysis, results in efficient competition of the energy transfer process to the Fc-based excited states with the CS process. These results highlight the key role played by diabatic state coupling, conformational dynamics, and Fc d-orbitals in shaping the ultrafast dynamics of Fc-based DBA systems, guiding the future design of photoactive materials for solar energy and molecular electronics applications.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Potential‑Driven Tetragonal CuFe2O4 Phase Transition Enables Near‑Complete Nitrate‑to‑Ammonia Conversion with Minimal Nitrite Accumulation(2026-07-05)The development of electrocatalyst for nearly complete electrocatalytic nitrate reduction without accumulating nitrites in the product feed is indispensable for sustainable nitrate contaminated wastewater treatment and carbon-neutral green ammonia production. In this study, CuFe 2 O 4 nanowires could mimic the bifunctional nature of nitrite reductase where Cu act as nitrate adsorption and deoxygenation center while Fe promoted adsorption of H* and the reduction of *NO to NH 2 . We demonstrate the involvement of a hydride‑transfer pathway supported by obtaining four‑electron transfer from rotating‑disk voltammetry and further corroborated by the mechanistic insights obtained from DFT analysis. The faradaic efficiency for ammonia exceeded 95% at all applied potentials, with an ammonia‑to‑nitrite yield‑rate ratio of 13 at −1.1 V vs. Reversible Hydrogen Electrode. The enhanced nitrite reduction was due to the potential dependent cubic to tetragonal phase transition at higher overpotential exposing undercoordinated iron sites promoting H* adsorption and hydrogenation of *NO. The tandem electrocatalysis mechanism led simultaneously to high NH 3 selectivity, suppressing hydrogen evolution reaction and resulting negligible nitrite accumulation. This work establishes a correlation between ammonia selectivity, surface structure and phase of spinel CuFe 2 O 4 and provides crucial mechanistic insights into reaction pathways of NO 3 - /NO 2 - electroreduction - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Polymorph-Dependent Photophysics of Blue-Emitting Brominated Organic Crystals(American Chemical Society, 2026-06-26)Nonmetal-containing organic molecules typically do not emit blue phosphorescence efficiently due to weak intersystem crossing and the challenge of protecting high-energy triplet states from nonradiative decay. We show that use of triplet-promoting bromine atoms and careful control of molecular packing can lead to well-defined, efficient room-temperature phosphorescence (RTP) from organic crystals. We report on the distinct optical properties of a polymorphic bromine-containing organic molecule, 1,4-bis-(bromomethyl)-2,5-bis-(octyloxy)-benzene (Br8) in solid-state (micro)-crystal and thin-film forms. The two polymorphs, named Br8-H and Br8-J, exhibit different molecular packing arrangements in single crystals and thin films and, consequently, different photophysical behaviors. The Br8-J polymorph is characterized by a head-to-tail molecular arrangement in a triclinic crystal, while the Br8-H polymorph adopts a face-to-face arrangement (monoclinic crystal). Br8-J has a higher quantum yield (38% for the microcrystal form and 8% for the thin film), lower energy, and narrower emission, compared to Br8-H (quantum yield of just 2% for the microcrystal and 0.2% in the thin film). The higher quantum yields in the microcrystal forms indicate the key role of intermolecular interactions in reducing nonradiative recombination in these polymorphs. The presence of both prompt and delayed blue emission (in the range 420-470 nm) and large Stokes shifts from both polymorphs indicates the involvement of triplet excited states and the occurrence of RTP with lifetimes of ∼325 μs. With an emission wavelength of 470 nm and a quantum yield of 38%, the Br8-J polymorph demonstrates how specific head-to-tail packing can unlock highly efficient solid-state phosphorescence compared to its face-to-face counterpart. The optimal intermolecular halide bonding in the J-type packing arrangement combined with the heavy atom effect is key to unlocking efficient blue emission from Br8 crystals. Our findings uncover rich photophysics in halogenated organic molecules in the solid state and the importance of molecular packing in their emission characteristics. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Photo-induced electron transfer dynamics and its mid-IR modulation of an ethyne bridged donor-acceptor complex(Royal Society of Chemistry, 2025-10-02)Electron transfer (ET) rate in donor–bridge–acceptor (DBA) complexes is modulated by the alkyne bridge vibrational excitation. Torsion angle ( θ ) offers selectivity in accessing locally-excited, acceptor-centered (S 2 ) state of the DBA complex.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Chitosan Eco-Friendly Approach to Oil Spill Cleanup: A Combined 2D TD-NMR Relaxation and Computational Modeling Study(Springer Science+Business Media, 2026-01-01)This work investigates the molecular interaction between chitosan, an effective and eco-friendly biopolymer, and crude oil components within petroleum emulsions. This mechanistic investigation combines 2D TD-NMR relaxation and computational modeling to understand chitosan’s role as an adsorbent and demulsifier for applications in environmental remediation. We applied a medium molecular mass chitosan to a series of six petroleum emulsions, spanning a representative range of medium and heavy crude oils (viscosities from 32.52 to 182.07 mm2.s-1 at 20 °C). The 2D D-T2 correlation maps were generated using the PFG-CPMG (Pulsed Field Gradient-Carr-Purcell-Meiboom-Gill) sequence to resolve the changes in oil and water mobility following chitosan addition. The key result is the observation of a characteristic shift in the diffusion coefficient (D) and transverse relaxation time (T2) of the oil component upon chitosan introduction. This shift provides direct evidence of the molecular interaction and the disruption of the emulsion stabilizing film. Furthermore, molecular modeling confirms strong water binding, complementing the TD-NMR findings. Overall, the study successfully demonstrates the utility of TD-NMR and molecular dynamics for mechanistic assessment, providing crucial, direct insight into the demulsification role of chitosan within petroleum emulsions. - Some of the metrics are blocked by yourconsent settings
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