Insight from Molecular Packing: Charge Transfer and Emission Modulation through Cocrystal Strategies

2020 ◽  
Vol 20 (8) ◽  
pp. 5203-5210
Author(s):  
Zeyang Ding ◽  
Hongxing Shang ◽  
Shitong Zhang ◽  
Wenkun Han ◽  
Bao Li ◽  
...  
2022 ◽  
Author(s):  
Yan Zeng ◽  
Guangchao Han ◽  
Yuanping Yi

Electrical conductivity is one of the key parameters for organic thermoelectrics and depends on both the concentration and mobility of charge carriers. To increase the carrier concentration, molecular dopants have to be added into organic semiconductor materials, whereas the introduction of dopants can influence the molecular packing structures and hence carrier mobility of the organic semiconductors. Herein, we have theoretically investigated the impact of different n-doping mechanisms on molecular packing and electron transport properties by taking N-DMBI-H and Q-DCM-DPPTT respectively as representative n-dopant and molecular semiconductor. The results show that when the doping reactions and charge transfer spontaneously occur in the solution at room temperature, the oppositely charged dopant and semiconductor molecules will be tightly bound to disrupt the semiconductor to form long-range molecular packing, leading to a substantial decrease of electron mobility in the doped film. In contrast, when the doping reactions and charge transfer are activated by heating the doped film, the molecular packing of the semiconductor is slight affected and hence the electron mobility remains quite high. This work indicates that thermally-activated n-doping is an effective way to achieve both high carrier concentration and high electron mobility in n-type organic thermoelectric materials.


Author(s):  
Yun Guo ◽  
Linli Yao ◽  
Ling Luo ◽  
Hang-Xing Wang ◽  
Ze Yang ◽  
...  

A novel strategy to synthesize 3-alkylaminomaleimide fluorophores via air oxidation is developed, and the structural features for the designed TICT fluorophores with bright emission are established.


2018 ◽  
Vol 20 (19) ◽  
pp. 13171-13177 ◽  
Author(s):  
Dongfeng Dang ◽  
Pei Zhou ◽  
Yong Wu ◽  
Yanzi Xu ◽  
Ying Zhi ◽  
...  

Isomeric TF1 and TF2 with fused-thiophene cores were developed to investigate their molecular packing properties, liquid crystalline properties and also charge transfer properties.


Author(s):  
J. Taft∅

It is well known that for reflections corresponding to large interplanar spacings (i.e., sin θ/λ small), the electron scattering amplitude, f, is sensitive to the ionicity and to the charge distribution around the atoms. We have used this in order to obtain information about the charge distribution in FeTi, which is a candidate for storage of hydrogen. Our goal is to study the changes in electron distribution in the presence of hydrogen, and also the ionicity of hydrogen in metals, but so far our study has been limited to pure FeTi. FeTi has the CsCl structure and thus Fe and Ti scatter with a phase difference of π into the 100-ref lections. Because Fe (Z = 26) is higher in the periodic system than Ti (Z = 22), an immediate “guess” would be that Fe has a larger scattering amplitude than Ti. However, relativistic Hartree-Fock calculations show that the opposite is the case for the 100-reflection. An explanation for this may be sought in the stronger localization of the d-electrons of the first row transition elements when moving to the right in the periodic table. The tabulated difference between fTi (100) and ffe (100) is small, however, and based on the values of the scattering amplitude for isolated atoms, the kinematical intensity of the 100-reflection is only 5.10-4 of the intensity of the 200-reflection.


Author(s):  
Yimei Zhu ◽  
J. Tafto

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.


2020 ◽  
Vol 8 (40) ◽  
pp. 20963-20969 ◽  
Author(s):  
Wei Chen ◽  
Guo-Bo Huang ◽  
Hao Song ◽  
Jian Zhang

An efficient charge transfer channel for improving the photocatalytic water splitting activity and durability of CdS without sacrificial agents.


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