scholarly journals Broadening the scope of uranyl photoreactivity: The oxidation of a uranyl complex anion in solid-state materials

Author(s):  
Jordan A. Herder ◽  
Aaron D. Nicholas ◽  
Christopher L. Cahill

Reported are the syntheses, structural characterizations and luminescence properties of three novel [UO2Cl4]2 bearing compounds containing substituted 1,1’-dialkyl-4,4’-bipyridinum dications (i.e. viologens). These compounds undergo photoinduced luminescence quenching upon exposure to UV radiation. Kinetic analyses indicate the degree of quenching follows a second-order rate law with a rate constant dependent on viologen substituent. This phenomenon is proposed to involve the formal transfer of one electron from the [UO2Cl4]2- to the viologen species. This proposed mechanism is supported through a series of calculations and computational work including Rehm-Weller analysis, time-dependent density functional theory (TD-DFT), and density of states (DOS). This work constitutes the first study of an oxidized uranyl complex anion which expands the conventional understanding of uranyl photoreactivity.

Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...


2017 ◽  
Vol 5 (24) ◽  
pp. 5984-5993 ◽  
Author(s):  
Jianguang Feng ◽  
Hongzhou Dong ◽  
Liyan Yu ◽  
Lifeng Dong

The effects of five types of oxygen-containing functional groups (–COOH, –COC–, –OH, –CHO, and –OCH3) on graphene quantum dots (GQDs) are investigated using time-dependent density functional theory (TD-DFT).


2014 ◽  
Vol 13 (11) ◽  
pp. 1549-1560 ◽  
Author(s):  
Divya Sharma ◽  
Martin J. Paterson

MP2, DFT and TD-DFT applied to benzene–(water)6 clusters show how both perturb the electronic spectra of each other and give rise to new charge transfer features from the benzene to the water cluster.


2015 ◽  
Vol 1131 ◽  
pp. 117-122
Author(s):  
Nikorn Shinsuphan ◽  
Sriprajak Krongsuk ◽  
Vittaya Amornkitbamrung

The photoluminescence properties of pristine adamantane molecule have been calculated by time-dependent density functional theory (TD-DFT) within the hybrid functional level. This study aims to investigate the luminescence properties of the pristine adamantane molecule and its functionalized with neutral and ion of alkali metal to form C10H16-nXn structure (where X is Li, Li+, Na and Na+ atoms, n=1). The electronic gap of the pristine adamantane (7.15 eV) is too wide, leading to an insulator property. While all the functionalized adamantanes exhibit semiconducting behavior. The absorption and emission energies of the original structure are 6.51 eV and 5.63 eV, respectively which are in good agreement with experimental results. The pure adamantane exhibits a broad photoluminescence peak in the ultraviolet region (UV). The Stokes shift of the transition between vertical and emission is 0.88 eV which agrees well with the previous work that measures the Stokes shift of 0.7 eV. The modification of adamantane indicates that the absorption and emission gaps substantially decreases. Substituting with alkali metal causes the photoluminescence onset can be shifted from the UV to the near-IR region. These results suggest that pure and the alkali metal functionalized adamantane molecules are promoting as candidate materials for the opto-electronic applications in the ultraviolet to infrared spectral regions.


2014 ◽  
Vol 16 (28) ◽  
pp. 14334-14356 ◽  
Author(s):  
Adèle D. Laurent ◽  
Carlo Adamo ◽  
Denis Jacquemin

We present a representative panel of TD-DFT applications in the colour chemistry field.


2017 ◽  
Vol 41 (5) ◽  
pp. 2020-2028 ◽  
Author(s):  
Njemuwa Nwaji ◽  
John Mack ◽  
Jonathan Britton ◽  
Tebello Nyokong

Ball-type phthalocyanines containing heavy central metals show enhanced nonlinear optical behaviour in solution or when embedded in polymer thin films. Time dependent density functional theory (TD-DFT) calculations were used to explain the spectra.


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