Some Recent Developments on the Synthesis, Chemical Reactivity, and Theoretical Studies of Tetroxanes

2013 ◽  
Vol 3 (1) ◽  
pp. 48-73
Author(s):  
Nelly L. Jorge ◽  
Alfonso Hernández-Laguna ◽  
Eduardo A. Castro
Keyword(s):  
Physical Chemistry ◽  
Triplet State ◽  
Critical Points ◽  
Ground State ◽  
Chemical Reactivity ◽  
Singlet Ground State ◽  
Theoretical Studies ◽  
Reaction Paths ◽  
Recent Developments

The authors present a review on some recent developments on the synthesis, chemical reactivity and theoretical studies of Tetroxanes analysing their main physical chemistry properties. The authors examine the critical points of the PES of different conformers, and reaction paths at singlet ground state and triplet state of the tetroxane, leader member of the cyclic diperoxide compound family.

scholarly journals Nature of ground and electronic excited states of higher acenes

2016 ◽  
Vol 113 (35) ◽  
pp. E5098-E5107 ◽  
Author(s):  
Yang Yang ◽  
Ernest R. Davidson ◽  
Weitao Yang
Keyword(s):  
Excited States ◽  
Ground State ◽  
Chemical Reactivity ◽  
Random Phase ◽  
Singlet Ground State ◽  
Short Axis ◽  
Singlet Fission ◽  
Shell Side ◽  
Electronic Excited States ◽  
Covalent Nature

Higher acenes have drawn much attention as promising organic semiconductors with versatile electronic properties. However, the nature of their ground state and electronic excited states is still not fully clear. Their unusual chemical reactivity and instability are the main obstacles for experimental studies, and the potentially prominent diradical character, which might require a multireference description in such large systems, hinders theoretical investigations. Here, we provide a detailed answer with the particle–particle random-phase approximation calculation. The 1Ag ground states of acenes up to decacene are on the closed-shell side of the diradical continuum, whereas the ground state of undecacene and dodecacene tilts more to the open-shell side with a growing polyradical character. The ground state of all acenes has covalent nature with respect to both short and long axes. The lowest triplet state 3B2u is always above the singlet ground state even though the energy gap could be vanishingly small in the polyacene limit. The bright singlet excited state 1B2u is a zwitterionic state to the short axis. The excited 1Ag state gradually switches from a double-excitation state to another zwitterionic state to the short axis, but always keeps its covalent nature to the long axis. An energy crossing between the 1B2u and excited 1Ag states happens between hexacene and heptacene. Further energetic consideration suggests that higher acenes are likely to undergo singlet fission with a low photovoltaic efficiency; however, the efficiency might be improved if a singlet fission into multiple triplets could be achieved.

Activation energy barrier for intersystem crossing in platinum phthalocyanine

1976 ◽  
Vol 54 (6) ◽  
pp. 633-637 ◽  
Author(s):  
Tzer-Hsiang Huang ◽  
Klaus E. Rieckhoff ◽  
Eva-Maria Voigt
Keyword(s):  
Triplet State ◽  
Ground State ◽  
Energy Barrier ◽  
Singlet State ◽  
Quantum Yields ◽  
Intersystem Crossing ◽  
Singlet Ground State ◽  
Activation Energy Barrier ◽  
Excited Singlet ◽  
Platinum Phthalocyanine

Phosphorescence quantum yields and lifetimes of platinum phthalocyanine in α-chloronaphthalene solution are reported for temperatures from 1.3 K to 300 K. Activation energies of intersystem crossing are deduced and found to be Ea = 17 ± 3 cm−1 for crossing from the first excited singlet state to the lowest lying triplet state and Eap = 8 ± 1 cm−1 for crossing from the lowest lying triplet state to the singlet ground state.

ChemInform Abstract: Some Recent Developments on the Synthesis, Chemical Reactivity, and Theoretical Studies of Tetroxanes

ChemInform ◽  
2013 ◽  
Vol 44 (37) ◽  
pp. no-no
Author(s):  
Nelly L. Jorge ◽  
Alfonso Hernandez-Laguna ◽  
Eduardo A. Castro
Keyword(s):  
Chemical Reactivity ◽  
Theoretical Studies ◽  
Recent Developments

Photoionization dynamics in CS fragmented from CS2 studied by high-resolution photoelectron spectroscopy

2004 ◽  
Vol 82 (6) ◽  
pp. 744-749
Author(s):  
Anouk M Rijs ◽  
Ellen HG Backus ◽  
Cornelis A de Lange
Keyword(s):  
High Resolution ◽  
Triplet State ◽  
Key Words ◽  
Excited States ◽  
Ground State ◽  
Photoelectron Spectroscopy ◽  
Electronic States ◽  
Reactive Intermediates ◽  
Photoelectron Spectra ◽  
Singlet Ground State

The photoionization dynamics of CS have been studied using high-resolution laser photoelectron spectroscopy. The photodissociation of CS2 at ~308 nm results in highly rotationally excited CS in its X1Σ+ singlet ground state, as well as in rotationally cold CS in the excited a3Π triplet state. The ground-state CS fragments are formed together with sulfur in its 3P, 1D, and 1S electronic states; triplet CS is produced in coincidence with ground-state sulfur (3P). In both channels the photoelectron spectra are dominated by Δv = 0 propensity, but transitions involving Δv = 1 and 2 are also observed. Key words: photoelectron spectroscopy, photoionization, photodissociation, excited states, reactive intermediates.

Chemical reactivity from the vibrational ground-state level. The role of the tunneling path in the tautomerization of urea and derivatives

2020 ◽  
Vol 22 (43) ◽  
pp. 24951-24963
Author(s):  
Irea Mosquera-Lois ◽  
David Ferro-Costas ◽  
Antonio Fernández-Ramos
Keyword(s):  
Low Temperature ◽  
Ground State ◽  
Chemical Reactivity ◽  
State Level ◽  
Chemical Processes ◽  
Vibrational Ground State ◽  
Recent Developments ◽  
Ground State Level

Recent developments of low-temperature techniques are providing valuable knowledge about chemical processes that manifest in the quantum regimen.

scholarly journals Negative ion photoelectron spectroscopy confirms the prediction that D3h carbon trioxide (CO3) has a singlet ground state

2016 ◽  
Vol 7 (2) ◽  
pp. 1142-1150 ◽  
Author(s):  
David A. Hrovat ◽  
Gao-Lei Hou ◽  
Bo Chen ◽  
Xue-Bin Wang ◽  
Weston Thatcher Borden
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Photoelectron Spectroscopy ◽  
Radical Anion ◽  
Negative Ion ◽  
Singlet Ground State

The CO3 radical anion (CO3˙−) has been formed by electrospraying carbonate dianion (CO32−) into the gas phase.

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