scholarly journals Molecular insertion regulates the donor-acceptor interactions in cocrystals for the design of piezochromic luminescent materials

2021 ◽  
Author(s):  
Chunguang Zhai ◽  
Xiu Yin ◽  
Shifeng Niu ◽  
Mingguang Yao ◽  
Shuhe Hu ◽  
...  
Keyword(s):  
Intermolecular Interactions ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Luminescent Materials ◽  
Conformation Change ◽  
Emission Enhancement ◽  
Donor Acceptor ◽  
Fine Manipulation

Abstract Developing a universal strategy to design new piezochromic luminescent materials with desirable properties remains challenging. Here, we report that insertion of a non-emissive molecule into a donor (perylene) and acceptor (TCNB) binary cocrystal can realize fine manipulation of intermolecular interactions between perylene and TCNB for desirable piezochromic luminescent properties. A continuous pressure-induced emission enhancement up to 3 GPa and a blue shift from 655 nm to 619 nm have been observed in perylene-TCNB cocrystals upon THF insertion, in contrast to the red-shifted and quenched emission observed when compressing perylene-TCNB cocrystals and other cocrystals reported earlier. By combining experiment with theory, it is further revealed that the inserted non-emissive THF forms blue-shifted H-bonds with neighboring TCNB molecules and promote a conformation change of perylene molecules upon compression, causing the blue-shifted and enhanced emission. This strategy remains valid when inserting other molecules as non-emissive component into perylene-TCNB cocrystals for abnormal piezochromic luminescent behaviors. Our strategy could also be extended to other cocrystals with different donor-acceptor components, opening a new way for designing novel piezochromic luminescent materials for future applications.

Cocrystals with tunable luminescence colour self-assembled by a predictable method

2018 ◽  
Vol 74 (6) ◽  
pp. 610-617 ◽  
Author(s):  
Lili Li ◽  
Zheng Fei Liu ◽  
Wen Xin Wu ◽  
Wei Jun Jin
Keyword(s):  
Intermolecular Interactions ◽  
Luminescent Properties ◽  
Delayed Fluorescence ◽  
Molecular Surface ◽  
Luminescent Materials ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Organic Light ◽  
Surface Electrostatic Potential ◽  
Bonding Patterns

Organic light-emitting materials play an essential role in the field of luminescent materials because they are easily prepared and they have controllable luminescent properties. Here it is shown that intermolecular interactions and luminescent properties of cocrystals can be predicted using the molecular surface electrostatic potential of selected π-hole/σ-hole...π bonding donor haloperfluorobenzenes and acceptor acenaphthene (AC). Single-crystal X-ray diffraction data reveal that actual bonding patterns in five cocrystals assembled from haloperfluorobenzenes and AC are in accordance with predictable patterns of intermolecular interactions; that is π-hole...π bond is the major interaction in AC–octafluoronaphthalene, AC–1,4-dibromotetrafluorobenzene and AC–1,3,5-tribromo-2,4,6-trifluorobenzene cocrystals, whereas σ-hole...π bond is the major interaction in AC–1,4-diiodotetrafluorobenzene and AC–1,3,5-trifluoro-2,4,6-triiodobenzene cocrystals. The luminescent properties of the cocrystals are affected by the bonding patterns between AC and haloperfluorobenzenes; the π-hole...π bond leads to weak phosphorescence, whereas the σ-hole...π bond results in weak delayed fluorescence and relatively strong phosphorescence.

scholarly journals Charge–Transfer Fluorescence and Room-Temperature Phosphorescence from a Bisamide-Based Derivative

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1370
Author(s):  
Chengjian Li ◽  
Chaozheng Zhuo ◽  
Jingwei Sun ◽  
Mi Ouyang
Keyword(s):  
Charge Transfer ◽  
Room Temperature ◽  
Luminescent Properties ◽  
Luminescent Materials ◽  
Room Temperature Phosphorescence ◽  
Single Crystal Structures ◽  
Singlet States ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
The Relationship

The development of organic luminescent materials with bimodal emissions of both fluorescence and room-temperature phosphorescent (RTP) remains a challenge. The investigation of the relationship between fluorescence and RTP performance is especially rare. In this work, we obtained an organic luminescent molecule, 1,4-phenylenebis((9H-carbazol-9-yl)methanone) (PBCM), which exhibits bimodal emissions of cyan fluorescence and yellow RTP in its crystalline state through adopting an electron donor–acceptor–donor (D–A–D) structure. The charge–transfer (CT) effects in the bimodal luminescent properties of PBCM, as well as the single-crystal structures and thermal properties, were investigated. It was found that the CT effect in the singlet states effectively reduces the ∆Est and promotes the ISC processes, resulting in an efficient phosphorescence of PBCM at room temperature. In addition, many strong intermolecular interactions are formed between the donor and acceptor parts of adjacent molecules, leading to the rigid configurations and compact packing of molecules in crystals, which was also confirmed to facilitate the efficient bimodal emissions of PBCM.

scholarly journals Thermal Stability and Luminescent Properties of Tri-cellulose Acetate Composites Containing Dy(SSA)3Phen Complex

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xiangwei Sun ◽  
Feiyue Wu ◽  
Yan Luo ◽  
Mengjun Huang ◽  
Yuntao Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Cellulose Acetate ◽  
Ternary Complex ◽  
Fluorescence Spectra ◽  
Luminescent Properties ◽  
Rare Earth Complex ◽  
Luminescent Materials ◽  
Sulfosalicylic Acid ◽  
Composition And Structure ◽  
Fluorescent Materials

Dysprosium (Dy) ternary complex was prepared using 5-sulfosalicylic acid (SSA) as the first ligand and 1,10-phenanthroline (Phen) as the second ligand, denoted as Dy(SSA)3Phen. The complex was blended with tri-cellulose acetate (TCA) via a cosolvent method to obtain polymer luminescent materials. The composition and structure of the rare-earth complex were characterized by means of elemental analysis, infrared (IR) spectra, and thermogravimetric analysis (TGA). The fluorescence spectra displayed this pure Dy(SSA)3Phen complex, and the TCA/Dy(SSA)3Phen composites all emit blue light. The (90/10) composite possesses fine luminescent properties with quantum yield of 33.5% and thermal stability for potential usage as blue fluorescent materials.

scholarly journals Tuning of Emission Wavelength of CaS:Eu by Addition of Oxygen Using Atomic Layer Deposition

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5966
Author(s):  
José Rosa ◽  
Jouko Lahtinen ◽  
Jaakko Julin ◽  
Zhipei Sun ◽  
Harri Lipsanen
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Inorganic Materials ◽  
Emission Wavelength ◽  
Layer Deposition ◽  
Fine Control ◽  
Novel Material ◽  
Luminescent Centers

Atomic layer deposition (ALD) technology has unlocked new ways of manipulating the growth of inorganic materials. The fine control at the atomic level allowed by ALD technology creates the perfect conditions for the inclusion of new cationic or anionic elements of the already-known materials. Consequently, novel material characteristics may arise with new functions for applications. This is especially relevant for inorganic luminescent materials where slight changes in the vicinity of the luminescent centers may originate new emission properties. Here, we studied the luminescent properties of CaS:Eu by introducing europium with oxygen ions by ALD, resulting in a novel CaS:EuO thin film. We study structural and photoluminescent properties of two different ALD deposited Eu doped CaS thin films: Eu(thd)3 which reacted with H2S forming CaS:Eu phosphor, or with O3 originating a CaS:EuO phosphor. It was found that the emission wavelength of CaS:EuO was 625.8 nm whereas CaS:Eu was 647 nm. Thus, the inclusion of O2− ions by ALD in a CaS:Eu phosphor results in the blue-shift of 21.2 nm. Our results show that ALD can be an effective way to introduce additional elements (e.g., anionic elements) to engineer the physical properties (e.g., inorganic phosphor emissions) for photonics and optoelectronics.

scholarly journals Synthesis and Luminescent Properties of Eu3+/Tb3+ Rare Earth Ions Doped Li2SrSiO4 Phosphors

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Kaitao Yu ◽  
Lifang Wei ◽  
Jiaqi Shen
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Band ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Rare Earth Ions ◽  
Luminescent Materials ◽  
Excitation Spectra ◽  
Solid State Method ◽  
X Ray ◽  
Uv Visible

The series of luminescent materials of Eu3 +, Tb3 + doped Li2SrSiO4 were synthesized by a high-temperature solid-state method. The phase purity of the samples was measured by X-ray powder diffraction (XRD). The luminescent properties of the samples were studied by UV-visible excitation spectra and emission spectra The It is found that the strong absorption of Eu3 + doped Li2-xSr1-xEuxSiO4 is from the 250 ~ 290 nm charge transfer band of Eu3 + and the 7F0 → 5L6 absorption transition of 393 nm. The strongest emission of the emission spectra at 393 nm is 614 nm and 701 nm, respectively, from the 5D0 → 7F2 and 5D0 → 7F4 transitions of Eu3 +. Tb3 + doped sample Li2-xSr1-xTb xSiO4 excitation spectrum is mainly composed of Tb3 + ion fd transition and charge transfer band composed of broadband, the strongest absorption at 269 nm, the emission of the main emission of 5D4 → 7F5 transition (542 nm).

Diluted exciplex concentration in organic light emitting diodes for blue-shifted spectra and improved efficiency

2022 ◽  
Author(s):  
Jiakui Yan ◽  
Bizheng Dong ◽  
Yabo Xu ◽  
Bo Zhao ◽  
Fangming Jin ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Blue Shift ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Host Materials ◽  
Donor Acceptor

In this work, the effects of different ratios of donor/acceptor and spacer host materials on exciplex organic light emitting diodes (OLED) based DMAC-DPS:PO-T2T were explored, an obvious spectral blue-shift and...

An Ultimate Investigation on the Adsorption of Amantadine on Pristine and Decorated Fullerenes C59X (X=Si, Ge, B, Al, Ga, N, P, and As): A DFT, NBO, and QTAIM Study

2020 ◽  
pp. 1-17
Author(s):  
Mohsen Doust Mohammadi ◽  
Idris H. Salih ◽  
Hewa Y. Abdullah
Keyword(s):  
Electronic Properties ◽  
Intermolecular Interactions ◽  
Density Functional ◽  
Physical Adsorption ◽  
Single Point ◽  
Basis Set ◽  
Total Density ◽  
Electron Configuration ◽  
Doped Fullerenes ◽  
Donor Acceptor

In this investigation, the feasibility of detecting the amantadine (AMD) molecule onto the outer surface of pristine fullerene (C[Formula: see text]), as well as C[Formula: see text]X ([Formula: see text], Ge, B, Al, Ga, N, P, and As) decorated structures, was carefully evaluated. For achieving this goal, a density functional theory level of study using the HSEH1PBE functional together with a 6-311G(d) basis set has been used. Subsequently, the B3LYP-D3, wB97XD and M062X functionals with a 6-311G(d) basis set were also employed to consider the single point energies. Natural bond orbital (NBO) and the quantum theory of atoms in molecules (QTAIM) were implemented using the B3LYP-D3/6-311G(d) method and the results were compatible with the electronic properties. In this regard, the total density of states (TDOSs), the Wiberg bond index (WBI), natural charge, natural electron configuration, donor–acceptor NBO interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All of the energy calculations and population analyses denote that by adsorbing of the AMD molecule onto the surface of the considered nanostructures, the intermolecular interactions are of the type of strong physical adsorption. Among the doped fullerenes, Ge-doped structure has very high adsorption energy compared to other elements. Generally, it was revealed that the sensitivity of the adsorption will be increased when the AMD molecule interacts with the decorated fullerenes and decrease the HOMO–LUMO band gap; therefore, the change of electronic properties can be used to design suitable nanocarrier.

scholarly journals Hypsochromic solvent shift of the charge separation band in ionic donor–acceptor Li+@C60⊂[10]CPP

2019 ◽  
Vol 55 (75) ◽  
pp. 11195-11198 ◽  
Author(s):  
Anton J. Stasyuk ◽  
Olga A. Stasyuk ◽  
Miquel Solà ◽  
Alexander A. Voityuk
Keyword(s):  
Electron Transfer ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Blue Shift ◽  
Polar Medium ◽  
Solvent Shift ◽  
Donor Acceptor

Photoinduced electron transfer in CPP-based donor–acceptor complexes C60⊂[10]CPP and Li+@C60⊂[10]CPP was studied using DFT/TDDFT. Unusual blue shift of charge separated states for Li+@C60⊂[10]CPP complexes in the polar medium is predicted.

Synthesis and characterization of YAG:Ce phosphors for white LEDs

2015 ◽  
Vol 23 (4) ◽  
Author(s):  
V. Tucureanu ◽  
A. Matei ◽  
A.M. Avram
Keyword(s):  
Sol Gel ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Temperature Treatment ◽  
Yttrium Aluminium Garnet ◽  
White Leds ◽  
Light Emitting Devices ◽  
Co Doping ◽  
Co Precipitation ◽  
Average Size

AbstractWorldwide commercial interest in the production of cerium doped yttrium aluminium garnet (YAG:Ce) phosphors is reflected in the widespread use of white light emitting devices. Despite of the fact that YAG:Ce is considered a “cool phosphor” it is the most important in white LED technology. This article reviews the developed techniques for producing phosphors with superior photoluminescence efficiency, including solid-state reaction, sol-gel and (co)precipitation methods. Also, by co-doping with rare earth elements, a red/blue shift is reached in the spectrum. The characteristics of YAG:Ce phosphors are investigated because the properties of the phosphors are strongly influenced by the synthesis routes and the sintering temperature treatment. After the phase analysis, morphology and emission studies of the phosphors there may be seen the conditions when the transition from the amorphous phase to the crystalline phase appears, when luminescent properties are influenced by the crystalline form, purity, average size of the particles, co-doping and so on.

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