Theoretical study on photo-induced processes of 1-methyl-3-(N-(1,8-naphthalimidyl)ethyl)imidazolium halide species: an application of constrained density functional theory

2018 ◽  
Vol 20 (6) ◽  
pp. 3911-3917 ◽  
Author(s):  
Takao Otsuka ◽  
Masato Sumita ◽  
Hironori Izawa ◽  
Kenji Morihashi
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Excited States ◽  
Density Functional ◽  
Theoretical Study ◽  
Functional Theory ◽  
Molecular Charge ◽  
Intra Molecular Charge Transfer

Inter-molecular charge transfer (SET) and intra-molecular charge transfer (SM1) excited states are involved in the photo-induced processes of 1-methyl-3-(N-(1,8-naphthalimidyl)ethyl)imidazolium halide.

A density functional theory and spectroscopic study of intramolecular quenching of metal-to-ligand charge-transfer excited states in some mono-bipyridine ruthenium(II) complexes

2014 ◽  
Vol 92 (10) ◽  
pp. 996-1009 ◽  
Author(s):  
Shivnath Mazumder ◽  
Ryan A. Thomas ◽  
Richard L. Lord ◽  
H. Bernhard Schlegel ◽  
John F. Endicott
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Charge Transfer ◽  
Excited States ◽  
Lower Energy ◽  
Density Functional ◽  
Dimethyl Sulfide ◽  
Intramolecular Electron Transfer ◽  
Functional Theory ◽  
Ligand Charge Transfer

The complexes [Ru(NCCH3)4bpy]2+ and [Ru([14]aneS4)bpy]2+ ([14]aneS4 = 1,4,8,11-tetrathiacyclotetradecane, bpy = 2,2′-bipyridine) have similar absorption and emission spectra but the 77 K metal-to-ligand charge-transfer (MLCT) excited state emission lifetime of the latter is less than 0.3% that of the former. Density functional theory modeling of the lowest energy triplet excited states indicates that triplet metal centered (3MC) excited states are about 3500 cm−1 lower in energy than their 3MLCT excited states in both complexes. The differences in excited state lifetimes arise from a much larger coordination sphere distortion for [Ru(NCCH3)4bpy]2+ and the associated larger reorganizational barrier for intramolecular electron transfer. The smaller ruthenium ligand distortions of the [Ru([14]aneS4)bpy]2+ complex are apparently a consequence of stereochemical constraints imposed by the macrocyclic [14]aneS4 ligand, and the 3MC excited state calculated for the unconstrained [Ru(S(CH3)2)4bpy]2+ complex (S(CH3)2 = dimethyl sulfide) is distorted in a manner similar to that of [Ru(NCCH3)4bpy]2+. Despite the lower energy calculated for its 3MC than 3MLCT excited state, [Ru(NCCH3)4bpy]2+ emits strongly in 77 K glasses with an emission quantum yield of 0.47. The emission is biphasic with about a 1 μs lifetime for its dominant (86%) emission component. The 405 nm excitation used in these studies results in a significant amount of photodecomposition in the 77 K glasses. This is a temperature-dependent biphotonic process that most likely involves the bipyridine-radical anionic moiety of the 3MLCT excited state. A smaller than expected value found for the radiative rate constant is consistent with a lower energy 3MC than 3MLCT state.

scholarly journals Double hybrids and time‐dependent density functional theory: An implementation and benchmark on charge transfer excited states

2020 ◽  
Vol 41 (13) ◽  
pp. 1242-1251 ◽  
Author(s):  
Alistar Ottochian ◽  
Carmela Morgillo ◽  
Ilaria Ciofini ◽  
Michael J. Frisch ◽  
Giovanni Scalmani ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Excited States ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Dependent Density

scholarly journals Charge-transfer excited states in phosphorescent organo-transition metal compounds: a difficult case for time dependent density functional theory?

RSC Advances ◽  
2015 ◽  
Vol 5 (78) ◽  
pp. 63318-63329 ◽  
Author(s):  
Thomas A. Niehaus ◽  
Thomas Hofbeck ◽  
Hartmut Yersin
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Transition Metal ◽  
Excited States ◽  
Density Functional ◽  
Time Dependent ◽  
Difficult Case ◽  
Functional Theory ◽  
Metal Compounds ◽  
Dependent Density

A series of 17 platinum(ii) and iridium(iii) complexes have been investigated theoretically and experimentally to elucidate the charge-transfer character in emission from the lowest triplet state. TDDFT is found to be surprisingly accurate.

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