Polarity and structure of derivatives of bis(2-phenylethyl)selenophosphinic acid

2017 ◽  
Vol 89 (3) ◽  
pp. 393-401 ◽  
Author(s):  
Yana Vereshchagina ◽  
Rezeda Khanafieva ◽  
Denis Chachkov ◽  
Eleonora Ishmaeva ◽  
Svetlana Malysheva ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Conformational Analysis ◽  
Density Functional ◽  
Conformational Equilibrium ◽  
Dipole Moments ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Derivatives Of

AbstractConformational analysis of derivatives of bis(2-phenylethyl)selenophosphinic acid was carried out by the method of dipole moments and density functional theory calculations. The conformations of the examined compounds fit into the overall conformational picture for the PIV compounds: these derivatives exist as conformational equilibrium of non-eclipsed gauche and trans forms with propeller arrangement of the substituents relative to the P=Se bond. We stipulate that the eclipsed cis orientation of substituent may be caused by the formation of H-contact.

Effects of S/Ce-codoping on electronic structures and optical properties of anatase TiO2 from density functional theory calculations

2015 ◽  
Vol 29 (35n36) ◽  
pp. 1550249
Author(s):  
Shi Wen Zhou ◽  
Jian Liu ◽  
Ping Peng ◽  
Wen Qin Chen
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Optical Absorption ◽  
Density Functional ◽  
Defect Formation ◽  
Dipole Moments ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Light Region ◽  
Rich Condition

The electronic and optical properties of S- and/or Ce-(co)doped anatase titanium dioxide (TiO2) are investigated using density functional theory plus U (DFT[Formula: see text]U) calculations. The optimized total energy suggests that TiO2 codoping by Ce and S favours the configuration of one substitutional Ce atom occupied on a Ti site with one substitutional S atom either on its nearest neighboring O or Ti site. The calculated results show that all doping configurations exhibit remarkable red-shift and excellent photocatalytic properties compared with pure TiO2. These reinforced features can mainly be ascribed to the appearance of S [Formula: see text] states in the top of valence band (VB) and Ce [Formula: see text] states in the bottom of conduction band (CB) as well as the contribution from the increasing octahedral dipole moments. The synergetic effects of cationic Ce and anionic S can extend optical absorption edge, which results in higher absorption coefficient in the visible light region than that of the anionic S monodoping and cationic Ce monodoping case; in the same time, decreasing the codoping concentration leads to reduced optical absorption. Additionally, Ce and S as cations incorporating into TiO2 lattices can induce stronger redox potential with a lower defect formation energy under O-rich condition compared with other doping systems.

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