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1.
J Am Chem Soc ; 146(31): 21752-21761, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39056815

RESUMO

Organic polyradicals with a high-spin ground state and quantum magnetic properties suitable for spin manipulation are valuable materials for diverse innovative technologies, including quantum devices. However, the typically high reactivity and low stability of conventional polyradicals present a major obstacle to such applications. In this study, a highly stable carbon-centered triradical TR with a quartet ground state and excellent stability (τ1/2 of ∼90 days in air-saturated toluene at room temperature) is achieved, which shows apposite magnetic anisotropy and Zeeman splitting partition with favorable addressability. By virtue of the optimal stability, thorough structural and magnetic characterizations are realized. With X-ray crystallography unambiguously proving the molecular structure, the quartet ground state (ΔED-Q = 0.78 kcal/mol) is confirmed by the SQUID measurements, while the cw- and pulsed EPR techniques offer additional supportive evidence for the high-spin nature. Remarkably, owing to the easily attained magnetic anisotropy, selective excitations between different Zeeman splitting levels are successfully demonstrated with TR in its frozen toluene solution without the requirement for special alignment, which is unprecedented for organic polyradicals. Along with the millisecond spin-lattice relaxation and microsecond coherence time manifested by TR, this triradical is promising for potential coherent spin manipulation applications as a multienergy-level quantum information carrier.

2.
J Am Chem Soc ; 146(28): 19397-19404, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38959221

RESUMO

The magnetoelectric material has attracted multidisciplinary interest in the past decade for its potential to accommodate various functions. Especially, the external electric field can drive the quantum behaviors of such materials via the spin-electric coupling effect, with the advantages of high spatial resolution and low energy cost. In this work, the spin-electric coupling effect of Mn2+-doped ferroelectric organic-inorganic hybrid perovskite [(CH3)3NCH2Cl]CdCl3 with a large piezoelectric effect was investigated. The electric field manipulation efficiency for the allowed transitions was determined by the pulsed electron paramagnetic resonance. The orientation-included Hamiltonian of the spin-electric coupling effect was obtained via simulating the angle-dependent electric field modulated continuous-wave electron paramagnetic resonance. The results demonstrate that the applied electric field affects not only the principal values of the zero-field splitting tensor but also its principal axis directions. This work proposes and exemplifies a route to understand the spin-electric coupling effect originating from the crystal field imposed on a spin ion being modified by the applied electric field, which may guide the rational screening and designing of hybrid perovskite ferroelectrics that satisfy the efficiency requirement of electric field manipulation of spins in quantum information applications.

3.
Small ; 20(6): e2304743, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37803930

RESUMO

Converting solar energy into hydrogen energy using conjugated polymers (CP) is a promising solution to the energy crisis. Improving water solubility plays one of the critical factors in enhancing the hydrogen evolution rate (HER) of CP photocatalysts. In this study, a novel concept of incorporating hydrophilic side chains to connect the backbones of CPs to improve their HER is proposed. This concept is realized through the polymerization of carbazole units bridged with octane, ethylene glycol, and penta-(ethylene glycol) to form three new side-chain-braided (SCB) CPs: PCz2S-OCt, PCz2S-EG, and PCz2S-PEG. Verified through transient absorption spectra, the enhanced capability of PCz2S-PEG for ultrafast electron transfer and reduced recombination effects has been demonstrated. Small- and wide-angle X-ray scattering (SAXS/WAXS) analyses reveal that these three SCB-CPs form cross-linking networks with different mass fractal dimensions (f) in aqueous solution. With the lowest f value of 2.64 and improved water/polymer interfaces, PCz2S-PEG demonstrates the best HER, reaching up to 126.9 µmol h-1 in pure water-based photocatalytic solution. Moreover, PCz2S-PEG exhibits comparable performance in seawater-based photocatalytic solution under natural sunlight. In situ SAXS analysis further reveals nucleation-dominated generation of hydrogen nanoclusters with a size of ≈1.5 nm in the HER of PCz2S-PEG under light illumination.

4.
Chemistry ; 30(36): e202401063, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38654592

RESUMO

14,14'-Bidibenzo[a,j]anthracenes (BDBAs) were prepared by iridium-catalyzed annulation of 5,5'-biterphenylene with alkynes. The molecular geometries of overcrowded BDBAs were verified by X-ray crystallography. The two dibenzo[a,j]anthryl moieties are connected through the sterically hindered 14 positions, resulting in highly distorted molecular halves. The conformation with a small twist angle between two molecular halves can minimize steric conflicts between the substituents at 1 and 13 positions and the carbon atoms of the central axis, as well as steric clashes between those substituents. One such example is octafluoro-substituted BDBA, where the interplanar angle between two anthryl moieties is approximately 31° (currently the lowest reported value, cf. 81° in 9,9'-bianthracene). The intramolecular interactions and electronic couplings between two molecular halves resulted in upfield 1H NMR signals, redshifted absorption and emission bands, and a reduced HOMO-LUMO gap. Photodynamic investigations on BDBAs indicated that the formation of the conventional symmetry-breaking charge transfer (SBCT) state was suspended by restricted rocking around the central C-C bond. Such a mechanism associated with this highly constrained conformation was examined for the first time.

5.
Chemistry ; 30(11): e202303523, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-37997021

RESUMO

A new series of biaryls, bi-linear-terphenylenes (BLTPs), were prepared using the tert-butyllithium-mediated cyclization as the key synthetic step. The three-dimensional structures of the studied compounds were verified using X-ray crystallography and DFT calculations. Tetraaryl(ethynyl)-substituted BLTPs are highly crowded molecules, and the internal rotation around the central C-C bond is restricted due to a high barrier (>50 kcal/mol). These structures contain several aryl/terphenylenyl/aryl sandwiches, where the through-space π-π (TSPP) interactions are strongly reflected in the shielding of 1 H NMR chemical shifts, reduction of oxidation potentials, increasing aromaticity of the central six-membered ring and decreasing antiaromaticity of the four-membered rings in a terphenylenyl moiety based on NICS(0) and iso-chemical shielding surfaces. Despite the restricted C-C bond associated intramolecular TSPP interactions for BLTPs in the ground state, to our surprise, the electronic coupling between two linear terphenylenes (LTPs) in BLTPs in the excited state is weak, so that the excited-state behavior is dominated by the corresponding monomeric LTPs. In other words, all BLTPs undergo ultrafast relaxation dynamics via strong exciton-vibration coupling, acting as a blue-light absorber with essentially no emission.

6.
Phys Chem Chem Phys ; 26(20): 14832-14838, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38721813

RESUMO

Magnetic molecules are promising candidates for quantum information processing (QIP) due to their tunable electron structures and quantum properties. A high spin Co(II) complex, CoH2dota, is studied for its potential to be used as a quantum bit (qubit) utilizing continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) spectroscopy at low temperature. On the X-band microwave energy scale, the system can be treated as an effective spin 1/2 with a strongly anisotropic g-tensor resulting from the significant spin-orbital coupling. An experimental and theoretical study is conducted to investigate the anisotropic Rabi oscillations of the two magnetically equivalent spin centres with different orientations in a single crystal sample, which aims to verify the relationship between the Rabi frequency and the orientation of the g-tensor. The findings of this study show that an effective quantum manipulation method is developed for orthorhombic spin systems.

7.
Artigo em Inglês | MEDLINE | ID: mdl-39043158

RESUMO

INTRODUCTION: It's crucial to utilize combination therapy for IgAN patients to reduce proteinuria and maintain stable kidney function. We demonstrate the safety and efficacy of low-dose spironolactone in management of IgAN patients. METHODS: Adult IgAN patients treated with spironolactone were evaluated. Patients were separated into two categories according to whether 24h-proteinuria was reduced by more than 20% after two-months of spironolactone treatment compared to baseline levels. RESULTS: 88 patients were analyzed and 24h-proteinuria decreased from 0.93g to 0.70 g (p<0.001) after two-months of treatment with spironolactone, accompanied by a slight decrease in EPI-eGFR from 75.7 to 73.9 mL/min/1.73 m2 (p = 0.033). Intriguingly, 47 patients in effective MRA group showed less endocapillary hypercellularity (p = 0.040). In ineffective group, 18 patients discontinued MRA treatment because of 24h-proteinuria increased from 0.83 g to 1.04 g, while the other 23 patients were continued with spironolactone and proteinuria decreased to 0.57 g in the sixth month (p = 0.001). Furthermore, 12 patients with persistent high proteinuria during prednisone therapy, were added with spironolactone. 24-proteinuria were dropped from 0.95 g to 0.73 g at the second month, and to 0.50 g at the sixth month. CONCLUSIONS: In our study, we confirmed spironolactone's efficacy in reducing urine protein excretion in IgA nephropathy patients within two months of treatment. However, response varied among patients, with those showing endocapillary proliferation (E1) in renal biopsies having poor spironolactone responsiveness. Administering mineralocorticoid receptor antagonists (MRAs) to patients with eGFR over 30 ml/min did not result in hyperkalemia, indicating the treatment's safety. Key Words:IgA Nephrology, Proteinuria, Spironolactone, Renal function.

8.
Clin Exp Nephrol ; 28(1): 23-30, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37713044

RESUMO

INTRODUCTION: There are increasing case reports on de novo or relapsing IgA nephropathy (IgAN) following SARS-CoV-2 vaccines, although the follow-up information on renal outcomes in IgAN patients post-SARS-CoV-2 vaccination is limited. In this study, we evaluated the renal outcomes of IgAN patients following inactivated vaccines. METHODS: We investigated the change in eGFR, proteinuria and hematuria in 113 primary IgAN patients post-vaccination. Worsening proteinuria was defined as an increase in proteinuria by more than 0.5 times and proteinuria > 1 g/d. Univariate and multivariable logistic regression analysis were used to evaluate possible predictors of worsening proteinuria. We then compared the renal outcomes of vaccinated patients after 6 months with 101 unvaccinated patients who were followed during the same period. RESULTS: A 2.54% (0.64, 8.61) decrease in renal function was observed in post-vaccination patients. Subgroup analysis revealed a significant decrease in eGFR in patients with 30 ≤ eGFR < 60 (mL/min/1.73 m2) post second SARS-CoV-2 dose (n = 18, p = 0.01). In addition, 10 individuals displayed worsening proteinuria post-vaccination, with the proteinuria subsequently ameliorating significantly after 6-month. Multivariate analysis showed that higher eGFR levels was an independent protective factor for worsening proteinuria. The renal outcome tended towards a decrease in eGFR in vaccinated patients after 6 months follow-up, although the difference was not significant (p = 0.06). CONCLUSION: Kidney function in IgAN patients tended to worsen after SARS-CoV-2 vaccination, particularly those with initial poor kidney function. This pattern of disease flare appears to be clinically mild, and further research is needed to determine whether the impact on kidney function is long-term.


Assuntos
COVID-19 , Glomerulonefrite por IGA , Humanos , Glomerulonefrite por IGA/complicações , Vacinas contra COVID-19/efeitos adversos , SARS-CoV-2 , COVID-19/prevenção & controle , COVID-19/complicações , Rim , Proteinúria/etiologia
9.
Angew Chem Int Ed Engl ; 63(27): e202401448, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38530747

RESUMO

Photogenerated radicals are an indispensable member of the state-of-the-art photochromic material family, as they can effectively modulate the photoluminescence and photothermal conversion performance of radical-induced photochromic complexes. Herein, two novel radical-induced photochromic metal-organic frameworks (MOFs), [Ag(TEPE)](AC) ⋅ 7/4H2O ⋅ 5/4EtOH (1) and [Ag(TEPE)](NC) ⋅ 3H2O ⋅ EtOH (2), are reported. Distinctly different topological networks can be obtained by judiciously introducing alternative π-conjugated anionic guests, including a new topological structure (named as sfm) first reported in this work, describing as 4,4,4,4-c net. EPR data and UV-Vis spectra prove the radical-induced photochromic mechanism. Dynamic photochromism exhibits tunability in a wide CIE color space, with a linear segment from yellow to red for 1, while a curved coordinate line for 2, resulting in colorful emission from blue to orange. Moreover, photogenerated TEPE* radicals effectively activate the near-infrared (NIR) photothermal conversion effect of MOFs. Under 1 W cm-2 808 nm laser irradiation, the surface temperatures of photoproducts 1* and 2* can reach ~160 °C and ~120 °C, respectively, with competitive NIR photothermal conversion efficiencies η=51.8 % (1*) and 36.2 % (2*). This work develops a feasible electrostatic compensation strategy to accurately introduce photoactive anionic guests into MOFs to construct multifunctional radical-induced photothermal conversion materials with tunable photoluminescence behavior.

10.
Angew Chem Int Ed Engl ; 63(16): e202401103, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38412017

RESUMO

Singlet fission (SF) holds great promise for current photovoltaic technologies, where tetracenes, with their relatively high triplet energies, play a major role for application in silicon-based solar cells. However, the SF efficiencies in tetracene dimers are low due to the unfavorable energetics of their singlet and triplet energy levels. In the solid state, tetracene exhibits high yields of triplet formation through SF, raising great interest about the underlying mechanisms. To address this discrepancy, we designed and prepared a novel molecular system based on a hexaphenylbenzene core decorated with 2 to 6 tetracene chromophores. The spatial arrangement of tetracene units, induced by steric hindrance in the central part, dictates through-space coupling, making it a relevant model for solid-state chromophore organization. We then revealed a remarkable increase in SF quantum yield with the number of tetracenes, reaching quantitative (196 %) triplet pair formation in hexamer. We observed a short-lived correlated triplet pair and limited magnetic effects, indicating ineffective triplet dissociation in these through-space coupled systems. These findings emphasize the crucial role of the number of chromophores involved and the interchromophore arrangement for the SF efficiency. The insights gained from this study will aid designing more efficient and technology-compatible SF systems for applications in photovoltaics.

11.
Angew Chem Int Ed Engl ; 63(32): e202407702, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38751355

RESUMO

The current bottleneck in the development of efficient photocatalysts for hydrogen evolution is the limited availability of high-performance acceptor units. Over the past nine years, dibenzo[b,d]thiophene sulfone (DBS) has been the preferred choice for the acceptor unit. Despite extensive exploration of alternative structures as potential replacements for DBS, a superior substitute remains elusive. In this study, a symmetry-breaking strategy was employed on DBS to develop a novel acceptor unit, BBTT-1SO. The asymmetric structure of BBTT-1SO proved beneficial for increasing multiple moment and polarizability. BBTT-1SO-containing polymers showed higher efficiencies for hydrogen evolution than their DBS-containing counterparts by up to 166 %. PBBTT-1SO exhibited an excellent hydrogen evolution rate (HER) of 222.03 mmol g-1 h-1 and an apparent quantum yield of 27.5 % at 500 nm. Transient spectroscopic studies indicated that the BBTT-1SO-based polymers facilitated electron polaron formation, which explains their superior HERs. PBBTT-1SO also showed 14 % higher HER in natural seawater splitting than that in deionized water splitting. Molecular dynamics simulations highlighted the enhanced water-PBBTT-1SO polymer interactions in salt-containing solutions. This study presents a pioneering example of a substitute acceptor unit for DBS in the construction of high-performance photocatalysts for hydrogen evolution.

12.
Small ; : e2308676, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072780

RESUMO

Highly emissive semiconductor nanocrystals, or so-called quantum dots (QDs) possess a variety of applications from displays and biology labeling, to quantum communication and modern security. Though ensembles of QDs have already shown very high photoluminescent quantum yields (PLQYs) and have been widely utilized in current optoelectronic products, QDs that exhibit high absorption cross-section, high emission intensity, and, most important, nonblinking behavior at single-dot level have long been desired and not yet realized at room temperature. In this work, infrared-emissive MAPbI3 -based halide perovskite QDs is demonstrated. These QDs not only show a ≈100% PLQY at the ensemble level but also, surprisingly, at the single-dot level, display an extra-large absorption cross-section up to 1.80 × 10-12 cm2 and non-blinking single photon emission with a high single photon purity of 95.3%, a unique property that is extremely rare among all types of quantum emitters operated at room temperature. An in-depth analysis indicates that neither trion formation nor band-edge carrier trapping is observed in MAPbI3 QDs, resulting in the suppression of intensity blinking and lifetime blinking. Fluence-dependent transient absorption measurements reveal that the coexistence of non-blinking behavior and high single photon purity in these perovskite QDs results from a significant repulsive exciton-exciton interaction, which suppresses the formation of biexciton, and thus greatly reduces photocharging. The robustness of these QDs is confirmed by their excellent stability under continuous 1 h electron irradiation in high-resolution transmission electron microscope inspection. It is believed that these results mark an important milestone in realizing nonblinking single photon emission in semiconductor QDs.

13.
Nephrology (Carlton) ; 28(1): 28-35, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36314193

RESUMO

AIM: Coronary artery calcification (CAC) is a common and severe complication in peritoneal dialysis (PD) patients, and it progresses in a majority of patients. Fetuin-A, encoded by the alpha 2-Heremans-Schmid glycoprotein (AHSG) gene, is a serum calcification inhibitor. The study aimed to examine the role of AHSG gene polymorphism rs4918 in CAC and CAC progression of PD patients. METHODS: Incident PD patients at Huashan Hospital Fudan University in China from August 2007 to July 2018 were recruited in this prospective study and followed up for 2 years. Patients underwent CAC measurements at recruitment and 2 years later. AHSG gene polymorphism rs4918 and serum fetuin-A were determined at baseline. The demographic characteristics, clinical data, and laboratory data were collected during the follow-up period. Binary logistic regression was performed to explore the association between rs4918 with CAC and CAC progression. RESULTS: A total of 202 PD patients (112 men, 55.4%) were recruited, with a mean age of 54 ± 16 years. The multivariate logistic regression identified genotype GG as an independent risk factor that correlates to CAC (odds ratio [OR] = 2.153; 95% CI: 1.182-3.925; p = .012) and CAC progression (OR = 2.482; 95% CI: 1.422-4.330; p = .001). The serum fetuin-A level was influenced by the rs4918 variants of AHSG, with a dose-dependent effect depending on the number of the G allele. CONCLUSION: AHSG gene polymorphism rs4918 affects serum fetuin-A levels and is significantly associated with both CAC and CAC progression in a cohort of patients receiving PD.


Assuntos
Doença da Artéria Coronariana , Diálise Peritoneal , alfa-2-Glicoproteína-HS , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , alfa-2-Glicoproteína-HS/genética , Doença da Artéria Coronariana/genética , Diálise Peritoneal/efeitos adversos , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Feminino
14.
Ren Fail ; 45(2): 2255679, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38346031

RESUMO

BACKGROUND AND AIM: Plasma fibrinogen has been proven to be significantly associated with cardiovascular mortality in patients undergoing peritoneal dialysis (PD). The study aimed to investigate the role of fibrinogen in left ventricular (LV) remodeling and functions in patients on PD, and explore risk factors related to high fibrinogen level. METHODS: From February 2008 to July 2018, adult patients on regular PD for at least 1 month were recruited and followed up for two years. Correlation analysis was performed to explore the fibrinogen level and echocardiography measurements. Pathogenic factors correlated to the left ventricular hypertrophy (LVH) progression were explored by logistic regression models and the role of fibrinogen in it was verified by receiver operating characteristic (ROC) curves. Linear regression models were conducted to identify factors associated with fibrinogen level. RESULTS: A total of 278 patients undergoing PD (168 males, 60.4%) were recruited. Patients were trisected according to fibrinogen levels at baseline. Mean wall thickness (MWT), relative wall thickness (RWT), and left ventricular mass index (LVMI) were positively associated with fibrinogen level while E/A ratio was negatively associated with it. Multivariate logistic regression and ROC curve showed that fibrinogen was an independent risk factor for LVH progression. Multivariate linear regression analysis identified age, total cholesterol (CHO), fasting blood glucose (FBG), and high-sensitivity C-reactive protein (hsCRP) were significantly related to plasma fibrinogen level. CONCLUSIONS: An elevated fibrinogen level was independently associated with LVH progression in patients undergoing PD. Older age, higher level of FBG, CHO, and hsCRP were risk factors for elevated plasma fibrinogen level.


Assuntos
Fibrinogênio , Diálise Peritoneal , Masculino , Adulto , Humanos , Proteína C-Reativa , Remodelação Ventricular , Diálise Peritoneal/efeitos adversos , Fatores de Risco , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/etiologia
15.
Angew Chem Int Ed Engl ; 62(49): e202314900, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-37851470

RESUMO

Stable carbon-based polyradicals exhibiting strong spin-spin coupling and slow depolarization processes are particularly attractive functional materials. A new molecular motif synthesized by a convenient method that allows the integration of stable, high-spin radicals to (hetero)aromatic polycycles has been developed, as illustrated by a non-Kekulé diradical showing a triplet ground state with long persistency (τ1/2 ≈31 h) in air. Compared to the widely used 1,3-phenylene, the newly designed (diaza)pyrene-4,10-diyl moiety is for the first time demonstrated to confer ferromagnetic (FM) spin coupling, allowing delocalized non-disjoint SOMOs. With the X-ray crystallography unambiguously proving the diradical structure, the triplet ground state was thoroughly characterized. A large ΔES-T of 1.1 kcal/mol, proving the strong FM coupling effect, was revealed consistently by superconducting quantum interference device (SQUID) measurements and variable-temperature electron paramagnetic resonance (EPR) spectroscopy, while the zero-field splitting and triplet nutation characters were examined by continuous-wave and pulsed EPR spectroscopy. A millisecond spin-lattice relaxation time was also detected. The current study not only offers a new molecular motif enabling FM coupling between carbon-based spins, but more importantly presents a general method for installing stable polyradicals into functional π-systems.

16.
Angew Chem Int Ed Engl ; 62(40): e202309831, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37594921

RESUMO

Self-assembled monolayers (SAMs) offer the advantage of facile interfacial modification, leading to significant improvements in device performance. In this study, we report the design and synthesis of a new series of carboxylic acid-functionalized porphyrin derivatives, namely AC-1, AC-3, and AC-5, and present, for the first time, a strategy to exploit the large π-moiety of porphyrins as a backbone for interfacing the indium tin oxide (ITO) electrode and perovskite active layer in an inverted perovskite solar cell (PSC) configuration. The electron-rich nature of porphyrins facilitates hole transfer and the formation of SAMs, resulting in a dense surface that minimizes defects. Comprehensive spectroscopic and dynamic studies demonstrate that the double-anchored AC-3 and AC-5 enhance SAMs on ITO, passivate the perovskite layer, and function as conduits to facilitate hole transfer, thus significantly boosting the performance of PSCs. The champion inverted PSC employing AC-5 SAM achieves an impressive solar efficiency of 23.19 % with a high fill factor of 84.05 %. This work presents a novel molecular engineering strategy for functionalizing SAMs to tune the energy levels, molecular dipoles, packing orientations to achieve stable and efficient solar performance. Importantly, our comprehensive investigation has unraveled the associated mechanisms, offering valuable insights for future advancements in PSCs.

17.
Angew Chem Int Ed Engl ; 62(16): e202300815, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-36825300

RESUMO

The exploration of deactivation mechanisms for near-infrared(NIR)-emissive organic molecules has been a key issue in chemistry, materials science and molecular biology. In this study, based on transient absorption spectroscopy and transient grating photoluminescence spectroscopy, we demonstrate that the aggregated PtII complex 4H (efficient NIR emitter) exhibits collective out-of-plane motions with a frequency of 32 cm-1 (0.96 THz) in the excited states. Importantly, similar THz characteristics were also observed in analogous PtII complexes with prominent NIR emission efficiency. The conservation of THz motions enables excited-state deactivation to proceed along low-frequency vibrational coordinates, contributing to the suppression of nonradiative decay and remarkable NIR emission. These novel results highlight the significance of excited-state vibrations in nonradiative processes, which serve as a benchmark for improving device performance.

18.
J Am Chem Soc ; 144(19): 8605-8612, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35512343

RESUMO

Manipulating quantum properties by electric fields using spin-electric coupling (SEC) effects promises spatial addressability. While several studies about inorganic materials showing the SEC functionality have been reported, the vastly tunable crystal structures of molecular ferroelectrics provide a range of rationally designable materials yet to be exploited. In this work, Mn2+-doped molecular ferroelectrics are chosen to experimentally demonstrate the feasibility of achieving the quantum coherent SEC effect in molecular ferroelectrics for the first time. The electric field pulse applied between Hahn-echo pulses in electron paramagnetic resonance (EPR) experiments causes controllable phase shifts via manipulating of the zero-field splitting (ZFS) of the Mn(II) ions. Detailed investigations of the aMn crystal showed unexpected SEC vanishment and enhancement at different crystal orientations, which were elucidated by studying the spin Hamiltonian and magnetic anisotropy. With the enhanced SEC efficiency being achieved (0.68 Hz m/V), this work discovers an emerging material library of molecular ferroelectrics to implement coherent quantum control with selective and tunable SEC effects toward highly scalable quantum gates.

19.
Opt Express ; 30(21): 38975-38984, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36258449

RESUMO

Stimulated Raman scattering (SRS) has attracted increasing attention in bio-imaging because of the ability toward background-free molecular-specific acquisitions without fluorescence labeling. Nevertheless, the corresponding sensitivity and specificity remain far behind those of fluorescence techniques. Here, we demonstrate SRS spectro-microscopy driven by a multiple-plate continuum (MPC), whose octave-spanning bandwidth (600-1300 nm) and high spectral energy density (∼1 nJ/cm-1) enable spectroscopic interrogation across the entire Raman active region (0-4000 cm-1), SRS imaging of a Drosophila brain, and electronic pre-resonance (EPR) detection of a fluorescent dye. We envision that utilizing MPC light source will substantially enhance the sensitivity and specificity of SRS by implementing EPR mode and spectral multiplexing via accessing three or more coherent wavelengths.


Assuntos
Microscopia , Análise Espectral Raman , Análise Espectral Raman/métodos , Microscopia/métodos , Corantes Fluorescentes , Microscopia Óptica não Linear , Vibração
20.
Opt Lett ; 47(17): 4423-4426, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36048669

RESUMO

The vortex beam (Laguerre-Gaussian, LG10 mode) is employed to alleviate crystal damage in multiple-plate continuum generation. We successfully compressed 190-fs, 1030-nm pulses to 42 fs with 590 µJ input pulse energy, which is 5.5 times higher than that obtained by a Gaussian beam setup of the same footprint. High throughput (86%) and high intensity-weighted beam homogeneity (>98%) have also been achieved. This experiment confirms the great potential of beam shaping in energy up-scaling of nonlinear pulse compression.

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