Lone-pair electron effect induced a rapid photorefractive response in site-controlled LiNbO3:Bi,M (M = Zn, In, Zr) crystals

2021 ◽  
Vol 118 (19) ◽  
pp. 191902
Author(s):  
Shuolin Wang ◽  
Yidong Shan ◽  
Weiwei Wang ◽  
Dahuai Zheng ◽  
Hongde Liu ◽  
...  
2020 ◽  
Vol 44 (4) ◽  
pp. 1228-1235
Author(s):  
Wenbing Cai ◽  
Qun Jing ◽  
Jun Zhang

We analyzed systematically each phase of BIBO, and we found that the synergistic effect between bismuth oxygen polyhedra and boron–oxygen groups codetermines the optical properties of BIBO.


2016 ◽  
Vol 55 (20) ◽  
pp. 10337-10342 ◽  
Author(s):  
Wen-Ping Zhao ◽  
Chao Shi ◽  
Alessandro Stroppa ◽  
Domenico Di Sante ◽  
Fanica Cimpoesu ◽  
...  

2019 ◽  
Vol 31 (3) ◽  
pp. 597-601
Author(s):  
A. Sangeetha ◽  
A. Thaminum Ansari ◽  
Jebakumar Jeevanandam ◽  
S. Jayaprakash

Sigmatropic rearrangement reaction of cycloprop-2-en-1-ol and its fluorine derivatives has been studied theoretically in gas phase and its energy barrier has been calculated. Nucleus-independent chemical shift (NICS) shows sigmatropic rearrangement of cycloprop-2-en-1-ol is pericyclic in nature whereas fluorine derivatives show pseudopericyclic and pericyclic nature. Substitution of fluorine atom at ring is found to increase the energy barrier for –OH migration, while substitution at oxygen atom reduces the barrier. To know the involvement of lone pair of electrons during the reaction, lone pair electron present on oxygen atom is locked by hydrogen bonding. CR-CCSD(T)/6-311+G** levels are used to study the reactions more accurately.


2005 ◽  
Vol 09 (08) ◽  
pp. 537-543 ◽  
Author(s):  
Yuping Lei ◽  
Jie Sun ◽  
Changjun Yang ◽  
Kejian Deng ◽  
Duoyuan Wang

An anion-resin carrying the catalyst iron(II) tetra(1,4-dithin)porphyrazine, ( Fe (II) Pz ( dtn )4/resin), may effectively interact with the lone-pair electron of the sulfur in the Fe (II) Pz ( dtn )4 to keep the absorption for the catalyst molecule, which can efficiently activate molecular oxygen coordinated with iron(II) on the axial orientation of Fe (II) Pz ( dtn )4 through electron transfer in a heterogeneous process. On the other hand, the hydrophilic property of the resin also facilitates adsorption of the anion-substrates in the aqueous solution onto the unoccupied resin surface to increase the substrate concentration around the Fe (II) Pz ( dtn )4 and the contact probability between the substrate with activated molecular oxygen to promote the oxidative degradation of these adsorbed substrates. The stability and repeatability of the Fe (II) Pz ( dtn )4/resin were determined by some control experiments. The results indicate that Fe (II) Pz ( dtn )4 was stable enough in the presence of active oxygen species under irradiation of visible light and could degrade recalcitrant organic pollutants such as rhodamine B and p-nitrobenzoic acid. It can be reused at least 5 cycling runs without losing activity.


2009 ◽  
Vol 87 (12) ◽  
pp. 1738-1746 ◽  
Author(s):  
Ping Qian ◽  
Li-Nan Lu ◽  
Zhong-Zhi Yang

The N-methylacetamide (NMA) is a very interesting kind of compound and often serves as a model of the peptide bond. The interaction between NMA and water provides a convenient prototype for the solvation of peptides in aqueous solutions. We have carried out molecular dynamics (MD) simulations of a NMA molecule in water under 1 atm and 298 K. The simulations make use of the newly developed NMA–water fluctuating charge ABEEM/MM potential model ( Yang, Z. Z.; Qian, P. J. Chem. Phys. 2006, 125, 064311 ), which is based on the combination of the atom-bond electronegativity equalization method (ABEEM) and molecular mechanics (MM). This model has been successfully applied to NMA–water gas clusters, NMA(H2O)n (n = 1–6), and accurately reproduced many static properties. For the NMA–water ABEEM/MM potential model, two characters must be emphasized in the simulations. Firstly, the model allows the charges in system to fluctuate, responding to the ambient environment. Secondly, for two major types of intermolecular hydrogen bonds, which are the hydrogen bond forming between the lone-pair electron on amide oxygen and the water hydrogen, and the one forming between the lone-pair electron on water oxygen and the amide hydrogen, we take special treatments in describing the electrostatic interaction by the use of the parameters klpO=,H and klpO–,HN–, respectively, which explicitly describe the short-range interaction of hydrogen bonds in the hydrogen bond interaction region. All sorts of properties have been studied in detail, such as, radial distribution function, energy distribution, ABEEM charge distribution and dipole moment, and so on. These simulation results show that the ABEEM/MM-based NMA–water potential model appears to be robust, giving the solution properties in excellent agreement with other dynamics simulations on similar systems.


2005 ◽  
Vol 34 (8) ◽  
pp. 1190-1191 ◽  
Author(s):  
Takashi Yamamoto ◽  
Daisuke Kaneno ◽  
Shuji Tomoda

2020 ◽  
Vol 56 (88) ◽  
pp. 13559-13562
Author(s):  
Lele Tang ◽  
Jie Zan ◽  
Hao Peng ◽  
Xi Yan ◽  
Ye Tao ◽  
...  

An X-ray excited organic afterglow scintillator is realized by embedding lone-pair electron involved n–π* transitions and charge transfer characters into H-aggregations.


2008 ◽  
Vol 07 (06) ◽  
pp. 1203-1214 ◽  
Author(s):  
WEI-QI LI ◽  
LI-LI LIU ◽  
JI-KANG FENG ◽  
ZI-ZHONG LIU ◽  
AI-MIN REN ◽  
...  

Ab initio calculations show that, for the P n( CH )4-n PH with n = 0 - 4, the fully optimized structures have decreasing pyramidality at the tri-coordinated phosphorus atom with n. The interaction between the tri-coordinated phosphorus [Formula: see text] and the carbons–phosphorus π-system [Formula: see text] with different n, the differences of the structure, electron properties and energy among the phospholes indicate that the ring strain and the delocalization of the lone pair electron of tri-coordinated phosphorus should be responsible for this phenomena. Various aromatic criteria such as geometry, magnetism, and energy show that these molecules are aromatic, and their aromaticities increase with the number of phosphorus atoms in the nonplanar pentagons. The electron circulation in the aromatic molecules can promote the delocalization of the lone pair. In contrast to the B3LYP prediction, we draw some similar conclusions, but the planarity and aromaticity of molecules increase largely at the MP2 lever due to the consideration of electron correlation.


Sign in / Sign up

Export Citation Format

Share Document