scholarly journals β-Diketonate ancillary ligands in heteroleptic iridium complexes: a balance between synthetic advantages and photophysical troubles

2018 ◽  
Vol 17 (9) ◽  
pp. 1169-1178 ◽  
Author(s):  
Marta Penconi ◽  
Marco Cazzaniga ◽  
Sagar Kesarkar ◽  
Clara Baldoli ◽  
Patrizia R. Mussini ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Excited States ◽  
Iridium Complexes ◽  
Triplet Energy ◽  
Ancillary Ligands ◽  
Phosphorescence Emission ◽  
Triplet Excited States ◽  
Shed Light

How the triplet energy of β-diketonate ancillary ligands in Ir(iii) complexes affects the phosphorescence emission: photochemical and electrochemical investigations and DFT calculations shed light on the dark triplet excited states.

Study of the triplet excited states and DFT calculations of iridium(III) complexes with mixed ligands

2018 ◽  
Vol 1164 ◽  
pp. 164-171
Author(s):  
Naokazu Yoshikawa ◽  
Shoko Yamazaki ◽  
Natsumi Kato ◽  
Nobuko Kanehisa ◽  
Tsuyoshi Inoue ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Excited States ◽  
Mixed Ligands ◽  
Triplet Excited States

TD-DFT calculations of the excited states of metalloporphyrins relevant to organic solar photovoltaic cells

2014 ◽  
Vol 18 (06) ◽  
pp. 475-492 ◽  
Author(s):  
Neha Agnihotri ◽  
Ronald P. Steer
Keyword(s):  
Dft Calculations ◽  
Electronic State ◽  
Excited States ◽  
Photovoltaic Cells ◽  
Oscillator Strengths ◽  
Solar Photovoltaic ◽  
Dft Methods ◽  
Radiative Transitions ◽  
Td Dft ◽  
Triplet Excited States

The molecular orbital energies and symmetries, electronic state energies and symmetries, and orbital compositions and oscillator strengths for one-photon radiative transitions up to an energy of 4 eV have been calculated by DFT and TD-DFT methods for 15 d0 and d10 metalloporphyrins. Data for both singlet and triplet excited states are reported and used to identify potential candidates for use as photon upconverters by homomolecular triplet–triplet annihilation.

Magnetic field effects on the quenching of triplet excitons in exciplex-based organic light emitting diodes

2018 ◽  
Vol 6 (21) ◽  
pp. 5721-5726 ◽  
Author(s):  
Peisen Yuan ◽  
Xianfeng Qiao ◽  
Donghang Yan ◽  
Dongge Ma
Keyword(s):  
Excited States ◽  
Light Emitting Diodes ◽  
Energy Levels ◽  
Organic Light Emitting Diodes ◽  
Magnetic Field Effects ◽  
Triplet Energy ◽  
Light Emitting ◽  
Organic Light ◽  
Triplet Excited States ◽  
Triplet Excitons

Triplet excited states in exciplex-based organic light emitting diodes (OLEDs) can be wasted by transferring their energy to the host material in a system with smaller triplet energy levels.

Rate Constant of Bimolecular Triplet Energy Transfer from Chrysene in the Higher Triplet Excited States

2004 ◽  
Vol 108 (35) ◽  
pp. 7147-7150 ◽  
Author(s):  
Xichen Cai ◽  
Masanori Sakamoto ◽  
Michihiro Hara ◽  
Sachiko Tojo ◽  
Kiyohiko Kawai ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited States ◽  
Rate Constant ◽  
Triplet Energy ◽  
Triplet Excited States ◽  
Triplet Energy Transfer

scholarly journals Pyridine imines as ligands in luminescent iridium complexes

2014 ◽  
Vol 43 (10) ◽  
pp. 4026-4039 ◽  
Author(s):  
David L. Davies ◽  
Francesco Lelj ◽  
Mark P. Lowe ◽  
Karl S. Ryder ◽  
Kuldip Singh ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Iridium Complexes ◽  
Alkyl Complexes ◽  
Shed Light

Biscyclometallated iridium complexes [Ir(ppz)2(X^Y)][PF6] (X^Y = pyridine imine) have been synthesised; N-alkyl complexes are emissive whilst N-aryl ones are only weakly emissive, DFT calculations shed light on the reasons for this difference.

Preparation of Bodipy–ferrocene dyads and modulation of the singlet/triplet excited state of bodipy via electron transfer and triplet energy transfer

2016 ◽  
Vol 4 (14) ◽  
pp. 2843-2853 ◽  
Author(s):  
Xueyan Wu ◽  
Wenting Wu ◽  
Xiaoneng Cui ◽  
Jianzhang Zhao ◽  
Mingbo Wu
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Excited State ◽  
Excited States ◽  
Singlet Excited State ◽  
Triplet Excited State ◽  
Triplet Energy ◽  
Triplet Excited States ◽  
Triplet Energy Transfer

Bodipy–ferrocene dyads were prepared for reversible electrochemical switching of the singlet excited state (fluorescence), as well as the triplet excited states of Bodipy.

Triplet state of orotic acid and orotic acid methyl ester in solution

1970 ◽  
Vol 48 (6) ◽  
pp. 987-999 ◽  
Author(s):  
R. W. Yip ◽  
W. D. Riddell ◽  
A. G. Szabo
Keyword(s):  
Methyl Ester ◽  
Excited States ◽  
Orotic Acid ◽  
Flash Photolysis ◽  
Acid Methyl Ester ◽  
Kcal Mole ◽  
Triplet Energy ◽  
Acid Methyl ◽  
Triplet Excited States ◽  
Triplet Energy Transfer

Flash photolysis of orotic acid and orotic acid methyl ester in aqueous solution was studied. The transients were identified as triplet excited states on the basis of their lifetimes, sensitization, quenching, and self-quenching experiments. The rate constants for self-quenching and for decay of the triplet were measured and discussed in terms of dimerization and competing unimolecular and pseudo-unimolecular processes. A triplet energy of 60 kcal mole−1 was deduced for both orotic acid and orotic acid methyl ester from triplet energy transfer measurements.

scholarly journals Tuning the singlet-triplet energy gap: a unique approach to efficient photosensitizers with aggregation-induced emission (AIE) characteristics

2015 ◽  
Vol 6 (10) ◽  
pp. 5824-5830 ◽  
Author(s):  
Shidang Xu ◽  
Youyong Yuan ◽  
Xiaolei Cai ◽  
Chong-Jing Zhang ◽  
Fang Hu ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Energy Gap ◽  
Intersystem Crossing ◽  
Triplet Excited State ◽  
Triplet Energy ◽  
Aggregation Induced Emission ◽  
Unique Approach ◽  
Triplet Excited States

The efficiency of the intersystem crossing process can be improved by reducing the energy gap between the singlet and triplet excited states (ΔEST), which offers the opportunity to improve the yield of the triplet excited state.

scholarly journals Triplet–triplet upconversion enhanced by spin–orbit coupling in organic light-emitting diodes

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ryota Ieuji ◽  
Kenichi Goushi ◽  
Chihaya Adachi
Keyword(s):  
Excited States ◽  
Light Emitting Diodes ◽  
Energy Levels ◽  
Molecular Structures ◽  
Organic Light Emitting Diodes ◽  
Triplet Energy ◽  
Light Emitting ◽  
Singlet Exciton ◽  
Organic Light ◽  
Triplet Excited States

AbstractTriplet–triplet upconversion, in which two triplet excitons are converted to one singlet exciton, is a well-known approach to exceed the limit of electroluminescence quantum efficiency in conventional fluorescence-based organic light-emitting diodes. Considering the spin multiplicity of triplet pairs, upconversion efficiency is usually limited to 20%. Although this limit can be exceeded when the energy of a triplet pair is lower than that of a second triplet excited state, such as for rubrene, it is generally difficult to engineer the energy levels of higher triplet excited states. Here, we investigate the upconversion efficiency of a series of new anthracene derivatives with different substituents. Some of these derivatives show upconversion efficiencies close to 50% even though the calculated energy levels of the second triplet excited states are lower than twice the lowest triplet energy. A possible upconversion mechanism is proposed based on the molecular structures and quantum chemical calculations.

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