28.2:Invited Paper: Reverse Intersystem Crossing From High-lying Triplet Energy Levels to Excited Singlet: A “Hot excition” Path for OLEDs

2015 ◽  
Vol 46 (1) ◽  
pp. 404-407 ◽  
Author(s):  
Dehua Hu ◽  
Liang Yao ◽  
Bing Yang ◽  
Yuguang Ma
Keyword(s):  
Energy Levels ◽  
Intersystem Crossing ◽  
Excited Singlet ◽  
Triplet Energy

Protonation of the Trimethylated Pyrichrominium Ion

1986 ◽  
Vol 41 (4) ◽  
pp. 661-664
Author(s):  
J. Koput ◽  
B. Marciniak ◽  
S. Paszyc
Keyword(s):  
Transfer Reaction ◽  
Energy Levels ◽  
Proton Transfer Reaction ◽  
Oscillator Strengths ◽  
Triplet States ◽  
Excited Singlet ◽  
Triplet Energy ◽  
Charge Densities ◽  
Singlet And Triplet States ◽  
Experimental Values

pKSpectroscopic manifestations of protonation of the trimethylated pyrichrominium ion studied previously experimentally [1] are investigated using a semiempirical INDO/S Cl method. Singlet and triplet energy levels of the free ion and several protonated species are calculated, and transition energies and oscillator strengths are compared with experimental spectra. Calculated charge densities on nitrogen atoms are correlated with experimental values for the ground and lowest excited singlet and triplet states. The possibility of the proton transfer reaction (phototautomerization) in the lowest excited singlet state of monoprotonated species is discussed on the basis of INDO/S Cl calculations, fluorescence and absorption spectroscopy.

Photolysis of ketene. I

1968 ◽  
Vol 46 (14) ◽  
pp. 2353-2360 ◽  
Author(s):  
A. N. Strachan ◽  
D. E. Thornton
Keyword(s):  
Carbon Monoxide ◽  
Quantum Yield ◽  
Triplet State ◽  
Singlet State ◽  
Inert Gases ◽  
Inert Gas ◽  
Excited Singlet State ◽  
Intersystem Crossing ◽  
Excited Singlet ◽  
Increasing Temperature

Ketene has been photolyzed at 3660 and 3130 Å both alone and in the presence of the inert gases C4F8 and SF6. The quantum yield of carbon monoxide has been determined at both wavelengths as a function of pressure and temperature. At 3660 Å the quantum yield decreases with increasing pressure but increases with increasing temperature. At 3130 Å the quantum yield with ketene alone remains 2.0 at both 37 and 100 °C at pressures up to 250 mm. At higher pressures of ketene or with added inert gas the quantum yield decreases with increasing pressure. The results are interpreted in terms of a mechanism in which intersystem crossing from the excited singlet state to the triplet state occurs at both wavelengths, and collisional deactivation of the excited singlet state by ketene is single stage at 3660 Å but multistage at 3130 Å.

Aggregation-induced emission (AIE)-active molecules bearing singlet oxygen generation activities: the tunable singlet–triplet energy gap matters

2019 ◽  
Vol 55 (10) ◽  
pp. 1450-1453 ◽  
Author(s):  
Chengkai Zhang ◽  
Yanqian Zhao ◽  
Dandan Li ◽  
Jiejie Liu ◽  
Heguo Han ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Cell Apoptosis ◽  
Near Infrared ◽  
Energy Gap ◽  
Intersystem Crossing ◽  
Triplet Energy ◽  
Oxygen Generation ◽  
Two Photon ◽  
Singlet Oxygen Generation ◽  
Infrared Excitation

Two-photon active photosensitizers showed relatively strong intersystem crossing facilitating 1O2 generation and cell apoptosis with near-infrared excitation.

The radiation-induced formation of excited states of aromatic hydrocarbons in alicyclic hydrocarbons I. Yields of excited singlet and triplet state solute molecules

1975 ◽  
Vol 347 (1648) ◽  
pp. 61-73 ◽  
Keyword(s):  
Energy Transfer ◽  
Excited States ◽  
Pulse Radiolysis ◽  
Minor Role ◽  
Intersystem Crossing ◽  
Excited Singlet ◽  
Excited Triplet ◽  
Upper Limit ◽  
Radiation Induced ◽  
A Minor

The dependences on concentration of the yield of excited triplet naphthalene, G ( 3 Naph٭), and of the radiation-induced fluorescence obtained on pulse radiolysis of solutions of naphthalene in cyclopentane, cyclooctane and decalin are reported. The yields of singlet excited naphthalene, G( 1 Naph٭), formed on pulse radiolysis of these solutions have been determined by comparing the intensity of the radiation-induced fluorescence with that obtained on photo excitation and the extent of formation of 3 Naph٭ by intersystem crossing, G ( 3 Naph٭) i. s. c., is assessed. Upper limit yields of solvent excited states, G ( 1 RH٭), were determined by measuring the extent of singlet energy transfer to toluene. It is concluded that energy transfer from solvent excited states plays a minor role in the formation of excited states of aromatic solutes.

The visible absorption spectrum of 1,2-cyclobutanedione in the gas phase

1986 ◽  
Vol 64 (11) ◽  
pp. 2152-2161 ◽  
Author(s):  
R. A. Back ◽  
J. M. Parsons
Keyword(s):  
Absorption Spectrum ◽  
Gas Phase ◽  
Singlet State ◽  
Energy Levels ◽  
Vibrational Structure ◽  
Visible Absorption Spectrum ◽  
Excited Singlet ◽  
Bending Vibration ◽  
Visible Absorption ◽  
Out Of Plane

The visible absorption spectrum of 1,2-cyclobutanedione has been measured in the gas phase at wavelengths between 4000 and 5100 Å. The absorption is attributed to the allowed π* ← n+, 1B1 ← 1A1 transition corresponding to the first excited singlet state. The spectrum shows a complex well-resolved vibrational structure which has been analysed, with some 125 bands measured and assigned. The bands at the longer wavelengths show sharp rotational fine structure, not yet analysed. The strongest band in the spectrum at 4933 Å has been assigned as the 0–0 band, while a band almost as strong at 4820 Å is attributed to excitation of one quantum of [Formula: see text], the a2 out-of-plane carbonyl bending vibration, and it is suggested that this band owes its intensity to vibronic coupling. A number of symmetric vibrations are also excited in the spectrum, but with no long progressions. Sequence bands running to the blue with an interval of about 72 cm−1 are prominent throughout the spectrum, and are assigned to v13, the a2 ring-twisting vibration. Other hot bands were also observed involving v13 which permitted estimation of energy levels for this vibration both in the ground state and the excited state. The infrared spectrum was also measured and analysed in the gas phase between 600 and 4000 cm−1, and 14 bands were assigned to fundamental vibrations; some of these assignments, at the lower frequencies, are uncertain.

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