scholarly journals Dependence of the Vertical Excitation Energy of Benzene on the Size and Force Constant of the Excited State

1966 ◽  
Vol 45 (10) ◽  
pp. 3879-3881 ◽  
Author(s):  
S. Ehrenson ◽  
Max Wolfsberg
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Force Constant ◽  
Vertical Excitation ◽  
Vertical Excitation Energy

scholarly journals Structure-Photochemical Function Relationships in Nitrogen-Containing Heterocyclic Aromatic Photobases Derived from Quinoline

2019 ◽  
Author(s):  
Sophya Alamudun ◽  
Kyle Tanovitz ◽  
April Fajardo ◽  
Kaitlind Johnson ◽  
Andy Pham ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Study ◽  
Experimental Studies ◽  
Substituent Effects ◽  
Vertical Excitation ◽  
Vertical Excitation Energy ◽  
Heterocyclic Aromatics ◽  
A Charge

<p>Photobases are compounds which become strong bases after electronic excitaton into a charge-transfer excited state. Recent experimental studies have highlighted the photobasicity of the 5-R quinoline compounds, demonstrating a strong substituent dependence to the pK<sub>a</sub><sup>*</sup>. Here we describe our systematic study of how the photobasicity of four families of nitrogen-containing heterocyclic aromatics are tuned through substituents. We show that substituent position and identity both significantly impact the pK<sub>a</sub><sup>*</sup>. We demonstrate that the substituent effects are additive and identify many disubstituted compounds with substantially greater photobasicity than the most photobasic 5-R quinoline compound identified previously. We show that the addition of a second fused benzene ring to quinoline, along with two electron-donating substituents, lowers the vertical excitation energy into the visible while still maintaining a pK<sub>a</sub><sup>*</sup> > 14. Overall, the structure-function relationships developed in this study provide new insights to guide the development of new photocatalysts that employ photobasicity. </p>

Structure-Photochemical Function Relationships in Nitrogen-Containing Heterocyclic Aromatic Photobases Derived from Quinoline

2020 ◽  
Author(s):  
Sophya Alamudun ◽  
Kyle Tanovitz ◽  
April Fajardo ◽  
Kaitlind Johnson ◽  
Andy Pham ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Study ◽  
Experimental Studies ◽  
Substituent Effects ◽  
Vertical Excitation ◽  
Vertical Excitation Energy ◽  
Heterocyclic Aromatics ◽  
A Charge

<p>Photobases are compounds which become strong bases after electronic excitaton into a charge-transfer excited state. Recent experimental studies have highlighted the photobasicity of the 5-R quinoline compounds, demonstrating a strong substituent dependence to the pK<sub>a</sub><sup>*</sup>. Here we describe our systematic study of how the photobasicity of four families of nitrogen-containing heterocyclic aromatics are tuned through substituents. We show that substituent position and identity both significantly impact the pK<sub>a</sub><sup>*</sup>. We demonstrate that the substituent effects are additive and identify many disubstituted compounds with substantially greater photobasicity than the most photobasic 5-R quinoline compound identified previously. We show that the addition of a second fused benzene ring to quinoline, along with two electron-donating substituents, lowers the vertical excitation energy into the visible while still maintaining a pK<sub>a</sub><sup>*</sup> > 14. Overall, the structure-function relationships developed in this study provide new insights to guide the development of new photocatalysts that employ photobasicity. </p>

scholarly journals Structure-Photochemical Function Relationships in Nitrogen-Containing Heterocyclic Aromatic Photobases Derived from Quinoline

2020 ◽  
Author(s):  
Sophya Alamudun ◽  
Kyle Tanovitz ◽  
April Fajardo ◽  
Kaitlind Johnson ◽  
Andy Pham ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Study ◽  
Experimental Studies ◽  
Substituent Effects ◽  
Vertical Excitation ◽  
Vertical Excitation Energy ◽  
Heterocyclic Aromatics ◽  
A Charge

<p>Photobases are compounds which become strong bases after electronic excitaton into a charge-transfer excited state. Recent experimental studies have highlighted the photobasicity of the 5-R quinoline compounds, demonstrating a strong substituent dependence to the pK<sub>a</sub><sup>*</sup>. Here we describe our systematic study of how the photobasicity of four families of nitrogen-containing heterocyclic aromatics are tuned through substituents. We show that substituent position and identity both significantly impact the pK<sub>a</sub><sup>*</sup>. We demonstrate that the substituent effects are additive and identify many disubstituted compounds with substantially greater photobasicity than the most photobasic 5-R quinoline compound identified previously. We show that the addition of a second fused benzene ring to quinoline, along with two electron-donating substituents, lowers the vertical excitation energy into the visible while still maintaining a pK<sub>a</sub><sup>*</sup> > 14. Overall, the structure-function relationships developed in this study provide new insights to guide the development of new photocatalysts that employ photobasicity. </p>

scholarly journals Accurate Prediction of the S1 Excitation Energy in Solvated Azobenzene Derivatives via Embedded Orbital-Tuned Bethe-Salpeter Calculations

2019 ◽  
Author(s):  
Aseem Rajan Kshirsagar ◽  
Gabriele D'Avino ◽  
Xavier Blase ◽  
Jing Li ◽  
Roberta Poloni
Keyword(s):  
Excitation Energy ◽  
Absolute Error ◽  
Hybrid Functional ◽  
Vertical Excitation ◽  
Exchange Correlation ◽  
Vertical Excitation Energy ◽  
Exact Exchange ◽  
Cis And Trans ◽  
Azobenzene Derivatives ◽  
Band Separation

By employing the Bethe-Salpeter formalism with a non-equilibrium embedding scheme, we demonstrate that the paradigmatic case of S<sub>1</sub> band separation between cis and trans in azobenzene derivatives can be computed with excellent accuracy compared to experimental optical spectra. Besides embedding, we show that the choice of the Kohn-Sham exchange correlation functional for DFT is critical, despite the iterative convergence of GW quasiparticle energies. We address this by using a global hybrid functional, PBEh, with the amount of exact exchange fulfilling the Koopman’s theorem for DFT hence yielding an environment-consistent ionization potential.<br>This method yields the first vertical excitation energy of 20 azo molecules with a mean absolute error as low as 0.06 eV, up to three times smaller compared to standard functionals such as M06-2X and PBE0, and five times smaller compared to recent TDDFT results.<br><br>

scholarly journals Accurate Prediction of the S1 Excitation Energy in Solvated Azobenzene Derivatives via Embedded Orbital-Tuned Bethe-Salpeter Calculations

2019 ◽  
Author(s):  
Aseem Rajan Kshirsagar ◽  
Gabriele D'Avino ◽  
Xavier Blase ◽  
Jing Li ◽  
Roberta Poloni
Keyword(s):  
Excitation Energy ◽  
Absolute Error ◽  
Hybrid Functional ◽  
Vertical Excitation ◽  
Exchange Correlation ◽  
Vertical Excitation Energy ◽  
Exact Exchange ◽  
Cis And Trans ◽  
Azobenzene Derivatives ◽  
Band Separation

By employing the Bethe-Salpeter formalism with a non-equilibrium embedding scheme, we demonstrate that the paradigmatic case of S<sub>1</sub> band separation between cis and trans in azobenzene derivatives can be computed with excellent accuracy compared to experimental optical spectra. Besides embedding, we show that the choice of the Kohn-Sham exchange correlation functional for DFT is critical, despite the iterative convergence of GW quasiparticle energies. We address this by using a global hybrid functional, PBEh, with the amount of exact exchange fulfilling the Koopman’s theorem for DFT hence yielding an environment-consistent ionization potential.<br>This method yields the first vertical excitation energy of 20 azo molecules with a mean absolute error as low as 0.06 eV, up to three times smaller compared to standard functionals such as M06-2X and PBE0, and five times smaller compared to recent TDDFT results.<br><br>

On the vertical excitation energy of cyclopentadiene

2004 ◽  
Vol 121 (11) ◽  
pp. 5236-5240 ◽  
Author(s):  
Yannick J. Bomble ◽  
Kurt W. Sattelmeyer ◽  
John F. Stanton ◽  
Jürgen Gauss
Keyword(s):  
Excitation Energy ◽  
Vertical Excitation ◽  
Vertical Excitation Energy

scholarly journals Ultrafast charge transfer dynamics in 2D Covalent Organic Frameworks/Re-complex hybrid photocatalyst for CO2 reduction: hot electrons vs. cold electrons

2021 ◽  
Author(s):  
Qinying Pan ◽  
Mohamed Abdellah ◽  
Yuehan Cao ◽  
Yang Liu ◽  
Weihua Lin ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Co2 Reduction ◽  
Underlying Mechanism ◽  
High Energy ◽  
Hot Electrons ◽  
Covalent Organic Frameworks ◽  
Energy Excitation ◽  
Energy Dependent

Abstract Rhenium(I)-carbonyl-diimine complexes are promising photocatalysts for CO2 reduction. Covalent organic frameworks (COFs) can be perfect sensitizers to enhance the reduction activities. Here we investigated the excited state dynamics of COF (TpBpy) with 2,2'-bipyridine incorporating Re(CO)5Cl (Re-TpBpy) to rationalize the underlying mechanism. The time-dependent DFT calculation first clarified excited state structure of the hybrid catalyst. The studies from transient visible and infrared spectroscopies revealed the excitation energy-dependent photo-induced charge transfer pathways in Re-TpBpy. Under low energy excitation, the electrons at the LUMO level are quickly injected from Bpy into ReI center (1–2 ps) followed by backward recombination (13 ps). Under high energy excitation, the hot-electrons are first injected into the higher unoccupied level of ReI center (1–2 ps) and then slowly relax back to the HOMO in COF (24 ps). There also remains long-lived free electrons in the COF moiety. This explained the excitation energy-dependent CO2 reduction performance in our system.

Ultrafast excited state dynamics of fucoxanthin: excitation energy dependent intramolecular charge transfer dynamics

2011 ◽  
Vol 13 (22) ◽  
pp. 10762 ◽  
Author(s):  
Daisuke Kosumi ◽  
Toshiyuki Kusumoto ◽  
Ritsuko Fujii ◽  
Mitsuru Sugisaki ◽  
Yoshiro Iinuma ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Intramolecular Charge Transfer ◽  
Excited State Dynamics ◽  
Charge Transfer Dynamics ◽  
Energy Dependent
Sign in / Sign up

Export Citation Format

Share Document