Theoretical understanding of two-photon-induced fluorescence of isomorphic nucleoside analogs

2015 ◽  
Vol 17 (15) ◽  
pp. 10053-10058 ◽  
Author(s):  
Pralok K. Samanta ◽  
Swapan K. Pati
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Nucleoside Analogs ◽  
Time Dependent ◽  
Photon Absorption ◽  
Theoretical Understanding ◽  
Functional Theory ◽  
Detailed Understanding ◽  
Two Photon ◽  
Tddft Calculations

We use ab initio Density Functional Theory (DFT) and Time-dependent DFT (TDDFT) calculations for a detailed understanding of one-photon absorption (1PA) and twophoton absorption (2PA) of eight isomorphic nucleoside analogs.

Bisporphyrin connected by tetrathiafulvalene

2009 ◽  
Vol 13 (01) ◽  
pp. 114-121 ◽  
Author(s):  
Kazuya Ogawa ◽  
Yasunori Nagatsuka
Keyword(s):  
Cross Section ◽  
Density Functional ◽  
Polar Solvent ◽  
Soret Band ◽  
Oxidation Potential ◽  
Time Dependent ◽  
Photon Absorption ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon

A new porphyrintetrathiafulvalene composite, where two porphyrins are bridged by te trathiafulvalene (TTF) using acetylene bonds was synthesized. The Q-band of the monomeric porphyrin appears at 590 nm whereas that of the composite is red-shifted to 620 nm and intensified. The Soret band is also red-shifted from 427 nm to 435 nm and much broadened, indicating the expansion of π-conjugation over the porphyrin and tetrathiafulvalene units. The HOMOs and LUMOs were calculated using time-dependent density functional theory. Voltammetric experiments revealed that the first oxidation potential of the TTF moiety in the composite was shifted by +155 mV compa red with TTF in the absence of composite. The effective two-photon absorption (2PA) cross section values were measured by using a nanosecond open aperture Z-scan method. The maximum effective 2PA cross section values were obtained at 760 nm, as 7300 GM in benzonitrile and 5900 GM in toluene. The values obtained in the polar solvent were 1.2 to 1.5 times larger than those in the nonpolar solvent.

scholarly journals Analysis and visualization of energy densities. II. Insights from linear-response time-dependent density functional theory calculations

2020 ◽  
Vol 22 (46) ◽  
pp. 26852-26864 ◽  
Author(s):  
Zheng Pei ◽  
Junjie Yang ◽  
Jingheng Deng ◽  
Yuezhi Mao ◽  
Qin Wu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Response Time ◽  
Linear Response ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Time Dependent ◽  
Functional Theory ◽  
Tddft Calculations ◽  
Density Analysis ◽  
Dependent Density

Inspired by the analysis of Kohn–Sham energy densities by Nakai and coworkers, we extended the energy density analysis to linear-response time-dependent density functional theory (LR-TDDFT) calculations.

Preparation and Photophysical Properties of All-trans Acceptor–π-Donor (Acceptor) Compounds Possessing Obvious Solvatochromic Effects

2017 ◽  
Vol 70 (9) ◽  
pp. 1048
Author(s):  
Yu-Lu Pan ◽  
Zhi-Bin Cai ◽  
Li Bai ◽  
Sheng-Li Li ◽  
Yu-Peng Tian
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Photon Absorption ◽  
Linear Absorption ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Donor Acceptor

A series of all-trans acceptor–π-donor (acceptor) compounds (BAQ, SFQ, BLQ, and XJQ) were conveniently synthesised and characterised by infrared, nuclear magnetic resonance, mass spectrometry, and elemental analysis. Their photophysical properties, including linear absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence, were systematically investigated. All the compounds show obvious solvatochromic effects, such as significant bathochromic shifts of the emission spectra and larger Stokes shifts in more polar solvents. Under excitation from a femtosecond Ti : sapphire laser with a pulse width of 140 fs, they all exhibit strong two-photon excited fluorescence, and the two-photon absorption cross-sections in THF are 851 (BAQ), 216 (SFQ), 561 (BLQ), and 447 (XJQ) GM respectively. A combination of density functional theory (DFT) and time-dependent density functional theory (TDDFT) approaches was used to investigate the relationships between the structures and the photophysical properties of these compounds. The results show that they may have a potential application as polarity-sensitive two-photon fluorescent probes.

Calculations of two-photon absorption cross sections by means of density-functional theory

2003 ◽  
Vol 374 (5-6) ◽  
pp. 446-452 ◽  
Author(s):  
Paweł Sałek ◽  
Olav Vahtras ◽  
Jingdong Guo ◽  
Yi Luo ◽  
Trygve Helgaker ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Cross Sections ◽  
Density Functional ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Functional Theory ◽  
Two Photon Absorption ◽  
Two Photon
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