Molecular Reorganization Research Articles

Theoretical perspective for structural isomerism effect on photoelectric properties of organic room temperature phosphorescence molecules

Purely organic room temperature phosphorescence (RTP) materials have garnered extensive attentions in anti-counterfeiting and encryption, information display, biological imaging and organic light emitting diodes (OLEDs) due to the features of long lifetimes, low toxicity and good biocompatibility. Nevertheless, both the species and amounts of the efficient RTP molecules are far from meeting the requirements for practical applications, and the quantitative relationship between molecular structures and optoelectronic properties needs full elucidated. Herein, the photophysical properties and properties of three isomers (o-BA, m-BA and p-BA) are explored based on the first-principles calculations coupled with thermal vibration correlation function (TVCF) method and kinetic Monte Carlo simulations. The substituent effects on the molecular structures, intermolecular interactions, transition properties, Huang-Rhys factors and reorganization energies, excited state dynamics as well as transfer integrals and charge carrier mobilities are investigated in detail to clarify the structure-property relationships. Results show that o-BA achieves fast radiative rate on account of impressive transition dipole moment and oscillator strength, but equally large non-radiative decay rate leads to low RTP efficiency. Promisingly, the highest holes mobility is determined for o-BA due to the largest transfer integrals of holes originating from the strong intermolecular interactions. In addition, compared with o-BA and p-BA, m-BA could achieve fast intersystem crossing (ISC) rate with large spin orbit coupling constant and low non-radiative decay rate with small geometric structure changes. Relatively balanced holes and electrons mobilities of m-BA have been demonstrated, which contributes to the recombination of excitons and the improvement of luminescence efficiency. For p-BA, the strong intermolecular hydrogen bonding restricts the free rotation of single bonds and promotes the molecular coplanarity, which contributes to efficient emission. Furthermore, the charge mobility is calculated and the temperature dependence is investigated, the hopping mechanisms for studied isomers are illustrated. This work reveals the relationship among molecular structures, crystal packing modes, photophysical properties and charge transport properties of isomers, and provides an insight for molecular design and property prediction.

Strategies Toward End-group Engineering of Chrysene Core-based Non-fullerene Acceptors for High Performance Organic Solar Cells: A DFT Study

In this study, seven new molecules (OA1–OA7) were introduced with the goal of enhancing the photovoltaic efficiency of solar cells. All these molecules were evaluated by using density functional theory (DFT). All the designed molecules have shorter band gap and higher values of [Formula: see text] than the reference. For confirming the charge mobility, the optoelectronic characterization has been carried out by densities of states (DOS), transition density matrix (TDM), molecular electrostatic potential (MEP) and reorganization energy. The [Formula: see text] values in designed molecules were also improved. The stability of designed molecules was also confirmed by the analysis of non-covalent interactions (NCIs). These results elaborate on the superiority of these novel-designed molecules over pre-existing (R) molecule as potential blocks for better organic solar cell applications.

Face-to-face conducting mechanism enabled by Si-C bonds for binder free Si@CNTs electrode

The three-dimensional conductive network has been developed, creating a continuous pathway for Si anodes. Nonetheless, the weak physical contact between Si particles and the conducting network is prone to separation due to expansion stress and the solid electrolyte interface. This results in a rapid decline in cell cycling performance. Herein, we have developed a binder free Si@CNTs fibrous thin film structure using carbon nanotube (CNT) conducting networks through a high vacuum magnetic sputtering process of molecular reorganization. With Fourier Transform Infrared (FTIR), X-ray Photoelectron Spectroscopy (XPS) tests and density functional theory (DFT) calculations, we propose a strong “face-to-face” contact configuration based on Si-C bonds. The Si@CNTs film demonstrated stable mechanical and electrical properties even after repeated bending and stretching of up to 6%. In-situ transmission electron microscopy confirmed that the initial cycling volume expansion of the Si@CNTs fibers with Si-C bonds was only 58.33%. Furthermore, the full cell using Si@CNTs anode enabled stable high-rate cycling performance at 6C after 500 cycles. This innovative strategy redefines the conductive mode of CNTs with Si anodes.

ULK1 forms distinct oligomeric states and nanoscopic structures during autophagy initiation.

Autophagy induction involves extensive molecular and membrane reorganization. Despite substantial progress, the mechanism underlying autophagy initiation remains poorly understood. Here, we used quantitative photoactivated localization microscopy with single-molecule sensitivity to analyze the nanoscopic distribution of endogenous ULK1, the kinase that triggers autophagy. Under amino acid starvation, ULK1 formed large clusters containing up to 161 molecules at the endoplasmic reticulum. Cross-correlation analysis revealed that ULK1 clusters engaging in autophagosome formation require 30 or more molecules. The ULK1 structures with more than the threshold number contained varying levels of Atg13, Atg14, Atg16, LC3B, GEC1, and WIPI2. We found that ULK1 activity is dispensable for the initial clustering of ULK1, but necessary for the subsequent expansion of the clusters, which involves interaction with Atg14, Atg16, and LC3B and relies on Vps34 activity. This quantitative analysis at the single-molecule level has provided unprecedented insights into the behavior of ULK1 during autophagy initiation.

Molecular Engineering of Anthracene Core-Based Hole-Transporting Materials for Organic and Perovskite Photovoltaics.

Anthracene core-based hole-transporting material containing TIPs (triisopropylsilylacetylene) has been spotlighted as potential donors for perovskite solar cells (SCs) due to their appropriate energy levels, efficient hole transport capacity, high stability, and high power conversion efficiency. Herein, we have efficiently designed seven new highly conjugated A-B-D-C-D molecules (AS1-AS7) containing an anthracene core. We used end-capped modifications of donor units with acceptor units on one side and then theoretically characterized them for their appropriate use for SC applications. Modern quantum chemistry techniques have theoretically described the R (reference molecule) and developed (AS1-AS7) molecules. Moreover, the proposed (AS1-AS7) molecules are explored with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) employing B3LYP/6-31G(d,p), and numerous parameters like photovoltaic, optical and electronic characteristics, frontier molecular orbital, excitation, binding and reorganization (λe and λh) energies, open circuit voltage, light harvesting efficiency, transition density matrix, fill factor, and the density of states have been studied. End-capped modification causes a smaller band gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), higher UV-vis absorption maxima, tuned energy levels, lower binding and reorganizational (λe and λh) energies, and larger Voc values in proposed (AS1-AS7) molecules than R. AS5 has a remarkable absorption maximum of 495.94 nm and a narrow optimal energy gap (Eg) of 1.46 eV. Furthermore, a complex study of AS5:PC61BM has revealed extraordinary charge shifting at the HOMO (AS5)-LUMO (PC61BM) interface. Our results suggested that newly developed anthracene core-based compounds (AS1-AS7) would be effective candidates with excellent photovoltaic and optoelectronic properties and could be employed in future organic and perovskite SC applications.

Achieving efficient flexible and large-area organic solar cells via additive-assisted fluorous solvent soaking

Developing flexible and large-area organic solar cells (OSCs) is of vital importance for advancing the commercialization. However, using solvent additives during the film deposition is tricky and unpredictable for the large-area device. Furthermore, typical post-treatments like high-temperature thermal annealing might cause the undesired deformation of the flexible substrate, thus adversely affecting the photovoltaic performance. Herein, a new device engineering namely additive-assisted fluorous solvent soaking (AFSS), is developed as an alternative approach for OSCs fabrication. No solvent additive is used in the active layer deposition, providing more uniform films in large-area processing. The fresh-made film is subsequently soaked in a mixture of fluorous solvent and a tiny amount of solvent additive, wherein the cyclic movement of the fluorous solvent associated with the additive could facilitate the molecular reorganization at relatively low temperature (40 °C), and thus optimizing the morphology of the active layer. Compared with the traditional method, AFSS is more effective in various OSCs including the rigid or flexible substrates and the conventional or inverted device architectures. An ultra-flexible and large-area device fabricated by AFSS realizes a PCE of 12.63%. This work provides a robust and practical strategy to fabricate OSCs as well as other optoelectronic devices at low temperature.

Impact of cooling rate and shear flow on crystallization and mechanical properties of wax-crystal networks

Wax oleogels are one of the most promising strategies to produce trans-fat free and low-saturate functional fats. Under quiescent isothermal conditions, waxes form strong space-filling networks where oil is embedded. Nevertheless, in industrial processes, crystallization conditions deviate significantly from being isothermal and quiescent, yet these far from equilibrium conditions have received limited attention in the literature. Cooling and shear rate gradients during crystallization can promote molecular alignment, crystal growth, and crystal network reorganization that hold the potential to tune the mechanical properties of oleogels. Therefore, this study aimed to investigate the impact of different controlled cooling and shear rates during the crystallization process of beeswax oleogels. An analysis of both small and large amplitude oscillatory shear was conducted to understand the linear and nonlinear mechanical properties of oleogels. Additionally, microscopic/macroscopic analyses, including oil-binding capacity, were performed. The results indicate that sheared oleogels display plastic-like behavior, lower linear elastic moduli, and a higher perfect plastic dissipation ratio than oleogels cooled under quiescent conditions, which displayed stiff, brittle-like characteristics. In addition, these oleogels displayed a microstructure with smaller crystals than oleogels cooled under quiescent conditions. This phenomenon can be attributed to a transition of oleogels from a strong, yet brittle interconnected particle network, to a dispersion of jammed crystal particles that align more easily along the direction of flow, resulting in minimal additional contribution from viscous stress after yielding. Therefore, a controlled cooling and shear rate application is an effective method to tune the mechanical properties of wax oleogels.

Molecular reorganisation during the spin-state transition of a [2×2] tetrairon(II) grid at equilibrium and out-of-equilibrium conditions

Molecular reorganisation during the spin-state transition of a [2×2] tetrairon(II) grid at equilibrium and out-of-equilibrium conditions

Space and Bond Synergistic Conjugation Controlling Multiple-Aniline NIR-II Absorption for Photoacoustic Imaging Guided Photothermal Therapy.

Currently, clinical photothermal therapy (PTT) is greatly limited by the poor tissue penetration of the excitation light sources in visible (390-780nm) and first near-infrared (NIR-I, 780-900nm) window. Herein, based on space and bond synergistic conjugation, a multiple-aniline organic small molecule (TPD), is synthesized for high-efficiency second near-infrared (NIR-II, 900-1700nm) photoacoustic imaging guided PTT. With the heterogeneity of six nitrogen atoms in TPD, the lone electrons on the nitrogen atom and the π bond orbital on the benzene ring form multielectron conjugations with highly delocalized state, which endowed TPD with strong NIR-II absorption (maximum peak at 925nm). Besides, according to the single molecular reorganization, the alkyl side chains on TPD make more free space for intramolecular motion to enhance the photothermal conversion ability. Forming TPD nanoparticles (NPs) in J-aggregation, they show a further bathochromic-shifted absorbance (maximum peak at 976nm) as well as a high photothermal conversion efficiency (66.7%) under NIR-II laser irradiation. In vitro and in vivo experiments demonstrate that TPD NPs can effectively inhibit the growth of tumors without palpable side effects. The study provides a novel NIR-II multiple-aniline structure based on multielectron hyperconjugation, and opens a new design thought for photothermal agents.

Water–soil interactions: Unravelling the processes and stages involved in the wetting of water repellent soils

The water repellent behaviour of soils is a widely studied phenomenon given its implications for infiltration, runoff, erosion and preferential flow. However, the principles underlying the eventual penetration of water into affected soils remain poorly understood. Theoretical considerations of the energetics and kinetics involved as a water drop makes contact with a water repellent soil surface and eventually penetrates into the soil suggest three distinct stages in the overall process. These stages are 1) adhesional wetting as soil and water first make contact, followed by 2) a kinetic barrier transitional stage in which molecular reorganisation of organics on soil reduces the water-soil contact angle to allow the water drop to sit deeper over soil particles of initial contact such that there is contact with particles in directly underlying soil layers, and finally 3) branching interstitial wetting as water penetrates into the bulk soil. Studies presented here of optical microscopy, mass of soil initially wetted, penetration time through layers of soil of different thicknesses, and time-dependent measurements of contact angle, volume of water penetrated, and mass of soil wetted, all give results consistent with this model. However, only for highly water repellent soils can distinct stages in wetting be clearly resolved experimentally, presumably because only these soils have a high enough kinetic barrier in the transitional stage for good separation between stages. For less water repellent soils, while the general time dependent behaviour remains consistent with the model, the distinction between the three stages is not so easy to resolve experimentally. The roles of contact angle, particle size distribution and drop size in determining the rates of these stages is considered, and the implications of the model for understanding soil water repellency are discussed.

High-pressure polymorphism in amoxicillin

This work is devoted to the pressure-induced structural transformations of amoxicillin by Raman and infrared spectroscopy at pressures up to 10 GPa. The Raman and infrared results indicate that amoxicillin underwent two phase transitions upon compression, specifically phase α → β and β → γ phase transitions at 2.71 GPa and 7.45 GPa. The significant changes of hydrogen bonding are indicated by the softened Raman modes, suggesting that the α → β phase transition may be a molecular layering reorganization process. The retrieved Raman and FT-IR spectra demonstrate that pressure-induced phase transitions are reversible upon decompression from 10 GPa to ambient pressure.

Revealing hidden structure in time-resolved spectral matrices using multivariate analysis of the streak camera data

Two new multi-stage smoothing LRA and PARAFAC-based methods were suggested and applied to study a 3D array composed of a set of the time-resolved spectral matrices (TRSM) containing instant fluorescence spectra of the fluorescein solution in methanol measured by the streak camera with picosecond resolution. Numerical modeling showed that both methods combined with Fourier processing allowed identifying the hidden structure of the pattern obscured entirely by noise. The PARAFAC algorithm was shown to have some advantages over LRA since the averaging of matrices in the last method causes information losses.Mathematical analysis of 20 TRSM of the fluorescein solution in methanol allowed us to expand the time range of instantaneous spectra while studying fast processes.The time dependence of the statistical moments of the spectra and their second-order derivatives was associated with the molecular reorganization processes of fluorescein solvates after absorption of excitation quanta.

Ab Initio Investigation of Intramolecular Charge Transfer States in DMABN by Calculation of Excited State X-ray Absorption Spectra

Dual fluorescence in 4-(dimethylamino)benzonitrile (DMABN) and its derivatives in polar solvents has been studied extensively for the past several decades. An intramolecular charge transfer (ICT) minimum on the excited state potential energy surface, in addition to the localized low-energy (LE) minimum, has been proposed as a mechanism for this dual fluorescence, with large geometric relaxation and molecular orbital reorganization a key feature of the ICT pathway. Herein, we have used both equation-of-motion coupled-cluster with single and double excitations (EOM-CCSD) and time-dependent density functional (TDDFT) methods to investigate the landscape of excited state potential energy surfaces across a number of geometric conformations proposed as ICT structures. In order to correlate these geometries and valence excited states in terms of potential experimental observables, we have calculated the nitrogen K-edge ground and excited state absorption spectra for each of the predicted "signpost" structures and identified several key spectral features that could be used to interpret a future time-resolved X-ray absorption experiment.

Trace Water Effects on Crystalline 1-Ethyl-3-methylimidazolium Acetate.

Spontaneous room-temperature crystallization of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was observed upon removal of trace water. Sample purity was confirmed using analytical nuclear magnetic resonance spectroscopy to ensure that trace water or other contaminants did not produce this observation. Raman spectroscopy and simultaneous quartz crystal microbalance/infrared spectroscopy measurements were used to study molecular reorganization during crystallization and decrystallization using trace water in the form of atmospheric moisture. These experimental results were supplemented with density functional theory calculations that indicate imidazolium cation ring stacking and side chain clustering with an exclusive arrangement of the acetate anion in the cation ring plane upon water removal. Crystal structure formation was confirmed using two-dimensional wide-angle X-ray scattering. This natural crystallization is attributed to the removal of trace water over extended periods of time and calls attention to the molecular-level role of water in the structure of hygroscopic ionic liquid systems.

Acacia senegal Budmunchiamines as a Potential Adjuvant for Rejuvenating Phenicol Activities towards Escherichia coli-Resistant Strains.

The continuous emergence of bacterial resistance alters the activities of different antibiotic families and requires appropriate strategies to solve therapeutic impasses. Medicinal plants are an attractive source for researching alternative and original therapeutic molecules. In this study, the fractionation of natural extracts from A. senegal and the determination of antibacterial activities are associated with molecular networking and tandem mass spectrometry (MS/MS) data used to characterize active molecule(s). The activities of the combinations, which included various fractions plus an antibiotic, were investigated using the "chessboard" test. Bio-guided fractionation allowed the authors to obtain individually active or synergistic fractions with chloramphenicol activity. An LC-MS/MS analysis of the fraction of interest and molecular array reorganization showed that most identified compounds are Budmunchiamines (macrocyclic alkaloids). This study describes an interesting source of bioactive secondary metabolites structurally related to Budmunchiamines that are able to rejuvenate a significant chloramphenicol activity in strains that produce an AcrB efflux pump. They will pave the way for researching new active molecules for restoring the activity of antibiotics that are substrates of efflux pumps in enterobacterial-resistant strains.

DNA Sensing Platforms: Novel Insights into Molecular Grafting Using Low Perturbative AFM Imaging.

By using AFM as a nanografting tool, we grafted micrometer-sized DNA platforms into inert alkanethiol SAMs. Tuning the grafting conditions (surface density of grafting lines and scan rate) allowed us to tailor the molecular density of the DNA platforms. Following the nanografting process, AFM was operated in the low perturbative Quantitative Imaging (QI) mode. The analysis of QI AFM images showed the coexistence of molecular domains of different heights, and thus different densities, within the grafted areas, which were not previously reported using contact AFM imaging. Thinner domains corresponded to low-density DNA regions characterized by loosely packed, randomly oriented DNA strands, while thicker domains corresponded to regions with more densely grafted DNA. Grafting with densely spaced and slow scans increased the size of the high-density domains, resulting in an overall increase in patch height. The structure of the grafted DNA was compared to self-assembled DNA, which was assessed through nanoshaving experiments. Exposing the DNA patches to the target sequence produced an increase in the patch height, indicating that hybridization was accomplished. The relative height increase of the DNA patches upon hybridization was higher in the case of lower density patches due to hybridization leading to a larger molecular reorganization. Low density DNA patches were therefore the most suitable for targeting oligonucleotide sequences.

Denervated mouse CA1 pyramidal neurons express homeostatic synaptic plasticity following entorhinal cortex lesion.

Structural, functional, and molecular reorganization of denervated neural networks is often observed in neurological conditions. The loss of input is accompanied by homeostatic synaptic adaptations, which can affect the reorganization process. A major challenge of denervation-induced homeostatic plasticity operating in complex neural networks is the specialization of neuronal inputs. It remains unclear whether neurons respond similarly to the loss of distinct inputs. Here, we used in vitro entorhinal cortex lesion (ECL) and Schaffer collateral lesion (SCL) in mouse organotypic entorhino-hippocampal tissue cultures to study denervation-induced plasticity of CA1 pyramidal neurons. We observed microglia accumulation, presynaptic bouton degeneration, and a reduction in dendritic spine numbers in the denervated layers 3 days after SCL and ECL. Transcriptome analysis of the CA1 region revealed complex changes in differential gene expression following SCL and ECL compared to non-lesioned controls with a specific enrichment of differentially expressed synapse-related genes observed after ECL. Consistent with this finding, denervation-induced homeostatic plasticity of excitatory synapses was observed 3 days after ECL but not after SCL. Chemogenetic silencing of the EC but not CA3 confirmed the pathway-specific induction of homeostatic synaptic plasticity in CA1. Additionally, increased RNA oxidation was observed after SCL and ECL. These results reveal important commonalities and differences between distinct pathway lesions and demonstrate a pathway-specific induction of denervation-induced homeostatic synaptic plasticity.

Interactive Organic Reaction Trajectory Animation iPhone Application (iORA) and Web Site (webORA)

Organic reaction trajectories show atomic motion and molecular reorganization of reactants during a single product-forming collision. iORA is a free (available from the Apple App Store), easy to use, highly interactive iPhone application that provides on-the-fly 3D rendering of organic reaction trajectories calculated with density functional theory (DFT) direct dynamics simulations. Visualization of trajectories using iORA enables qualitative and quantitative learning about organic reaction pathways. iORA users can interactively zoom, rotate, and translate the reaction animations. Users can track distances, angles, and dihedral angles. Other iORA features include buttons to jump to the transition state, control the animation speed, and 3D image display. Currently available reaction classes include Bronsted acid–base, alkyl substitution, alkene addition, alkyne addition, diene addition, rearrangement, oxidation, reduction, carbonyl addition, radical, pericyclic, and aromatic substitution. WebORA is a web-based site that also displays interactive DFT-based organic reaction trajectory simulations from these reaction classes. It can be used by all web browsers and operating systems. iORA and webORA also offer brief trajectory descriptions.

Mapping the SLP76 interactome in T cells lacking each of the GRB2-family adaptors reveals molecular plasticity of the TCR signaling pathway.

The propagation and diversification of signals downstream of the T cell receptor (TCR) involve several adaptor proteins that control the assembly of multimolecular signaling complexes (signalosomes). The global characterization of changes in protein-protein interactions (PPI) following genetic perturbations is critical to understand the resulting phenotypes. Here, by combining genome editing techniques in T cells and interactomics studies based on affinity purification coupled to mass spectrometry (AP-MS) analysis, we determined and quantified the molecular reorganization of the SLP76 interactome resulting from the ablation of each of the three GRB2-family adaptors. Our data showed that the absence of GADS or GRB2 induces a major remodeling of the PPI network associated with SLP76 following TCR engagement. Unexpectedly, this PPI network rewiring minimally affects proximal molecular events of the TCR signaling pathway. Nevertheless, during prolonged TCR stimulation, GRB2- and GADS-deficient cells displayed a reduced level of activation and cytokine secretion capacity. Using the canonical SLP76 signalosome, this analysis highlights the plasticity of PPI networks and their reorganization following specific genetic perturbations.

Efficient Near-Infrared Luminescence of Self-Assembled Platinum(II) Complexes: From Fundamentals to Applications.

ConspectusDesigning bright and efficient near-infrared (NIR) emitters has drawn much attention due to numerous applications ranging from biological imaging, medical therapy, optical communication, and night-vision devices. However, polyatomic organic and organometallic molecules with energy gaps close to the deep red and NIR regime are subject to dominant nonradiative internal conversion (IC) processes, which drastically reduces the emission intensity and exciton diffusion length of organic materials and hence hampers the optoelectronic performances. To suppress nonradiative IC rates, we suggested two complementary approaches to solve the issues: exciton delocalization and molecular deuteration. First, exciton delocalization efficiently suppresses the molecular reorganization energy through partitioning to all aggregated molecules. According to the IC theory together with the effect of exciton delocalization, the simulated nonradiative rates with the energy gap ΔE = 104 cm-1 decrease by around 104 fold when the exciton delocalization length equals 5 (promoting vibronic frequency ωl = 1500 cm-1). Second, molecular deuterations reduce Franck-Condon vibrational overlaps and vibrational frequencies of promoting modes, which decreases IC rates by 1 order of magnitude in comparison to the rates of nondeuterated molecules under ΔE of 104 cm-1. Although deuteration of molecules has long been attempted to increase emission intensity, the results have been mixed. Here, we provide a robust derivation of the IC theory to demonstrate its validity, especially to emission in the NIR region.The concepts are experimentally verified by the strategic design and synthesis of a class of square-planar Pt(II) complexes, which form crystalline aggregates in vapor deposited thin films. The packing geometries are well characterized by the grazing angle X-ray diffraction (GIXD), showing domino-like packing arrangements with the short ππ separation of 3.4-3.7 Å. Upon photoexcitation, such closely packed assemblies exhibit intense NIR emission maximized in the 740-970 nm region through metal-metal-to-ligand charge transfer (MMLCT) transition with unprecedented photoluminescent quantum yield (PLQY) of 8-82%. To validate the existence of exciton delocalization, we applied time-resolved step-scan Fourier transform UV-vis spectroscopy to probe the exciton delocalization length of Pt(II) aggregates, which is 5-9 molecules (2.1-4.5 nm) assuming that excitons mainly delocalized along the direction of ππ stacking. According to the dependence of delocalization length vs simulated IC rates, we verify that the observed delocalization lengths contribute to the high NIR PLQY of the aggregated Pt(II) complexes. To probe the isotope effect, both partially and completely deuterated Pt(II) complexes were synthesized. For the case of the 970 nm Pt(II) emitter, the vapor deposited films of per-deuterated Pt(II) complexes exhibit the same emission peak as that of the nondeuterated one, whereas PLQY increases ∼50%. To put the fundamental studies into practice, organic light-emitting diodes (OLEDs) were fabricated with a variety of NIR Pt(II) complexes as the emitting layer, showing the outstanding external quantum efficiencies (EQEs) of 2-25% and the remarkable radiances 10-40 W sr-1 m-2 at 740-1002 nm. The prominent device performances not only successfully prove our designed concept but also reach a new milestone for highly efficient NIR OLED devices.This Account thus summarizes our approaches about how to boost the efficiency of the NIR emission of organic molecules from an in-depth fundamental basis, i.e., molecular design, photophysical characterization, and device fabrication. The concept of the exciton delocalization and molecular deuteration may also be applicable to a single molecular system to achieve efficient NIR radiance, which is worth further investigation in the future.