The activity of lone pair contributing to SHG response in bismuth borates: a combination investigation from experiment and DFT calculation

2017 ◽  
Vol 19 (37) ◽  
pp. 25270-25276 ◽  
Author(s):  
Cong Hu ◽  
Miriding Mutailipu ◽  
Ying Wang ◽  
Fengjiao Guo ◽  
Zhihua Yang ◽  
...  

A theoretical estimation for the intensity of the Bi-6s stereochemically active lone pair (SCALP) is built, quantified by the RSCA factor, which indicates that a larger RSCA factor is beneficial for a larger SHG response.

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.


2020 ◽  
Author(s):  
Olivier Charles Gagné

The scarcity of nitrogen in Earth’s crust, combined with challenging synthesis, have made inorganic nitrides a relatively-unexplored class of compounds compared to their naturally-abundant oxide counterparts. To facilitate exploration of their compositional space via <i>a priori</i> modeling, and to help <i>a posteriori</i> structure verification not limited to inferring the oxidation state of redox-active cations, we derive a suite of bond-valence parameters and Lewis-acid strength values for 76 cations observed bonding to N<sup>3-</sup>, and further outline a baseline statistical knowledge of bond lengths for these compounds. We examine structural and electronic effects responsible for the functional properties and anomalous bonding behavior of inorganic nitrides, and identify promising venues for exploring uncharted compositional spaces beyond the reach of high-throughput computational methods. We find that many mechanisms of bond-length variation ubiquitous to oxide and oxysalt compounds (e.g., lone-pair stereoactivity, the Jahn-Teller and pseudo Jahn-Teller effects) are similarly pervasive in inorganic nitrides, and are occasionally observed to result in greater distortion magnitude than their oxide counterparts. We identify inorganic nitrides with multiply-bonded metal ions as a promising venue in heterogeneous catalysis, e.g. in the development of a post-Haber-Bosch process proceeding at milder reaction conditions, thus representing further opportunity in the thriving exploration of the functional properties of this emerging class of materials.<br>


2017 ◽  
Author(s):  
Arpita Yadav ◽  
Dasari L V K Prasad ◽  
Veejendra Yadav

<p>The torquoselectivity, the inward or outward ring opening of 3-substituted cyclobutenes, is conventionally guided by the donor and/or acceptor ability of the substituent (S). It is typically predicted by estimating the respective ring opening transition state (TS) barriers. While there is no known dissent in regard to the outward rotation of electron-rich substituents from the approaches of TS calculations, the inward rotation was predicted for some electron-accepting substituents and outward for others. To address this divergence in predicting the torquoselectivity, we have used reliable orbital descriptors through natural bond orbital theoretical calculations and demonstrated that (a) interactions <i>n</i><i><sub>S</sub></i>→s*<sub>C3C4</sub> for a lone pair containing substituent, s<sub>S</sub>→s*<sub>C3C4</sub> for a s-donor substituent, s<sub>C3C4</sub>→p*<sub>S</sub> for a resonance-accepting substituent and s<sub>C3C4</sub>→s*<sub>S</sub> for a s-acceptor substituent constitute the true electronic controls of torquoselectivity, and (b) reversibility of the ring opening event is an additional important contributor to the observed product distribution.</p>


Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.


Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.


Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne

Bond-length distributions are examined for three configurations of the H+ ion, sixteen configurations of the group 14-16 non-metal ions and seven configurations of the group 17 ions bonded to oxygen. Lone-pair stereoactivity for ions bonded to O<sup>2-</sup> is discussed, as well as the polymerization of the PO<sub>4</sub> group.


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