scholarly journals A Stable Saddle-Shaped Polycyclic Hydrocarbon with an Open-Shell Singlet Ground State

2017 ◽  
Vol 129 (12) ◽  
pp. 3328-3332 ◽  
Author(s):  
Ji Ma ◽  
Junzhi Liu ◽  
Martin Baumgarten ◽  
Yubin Fu ◽  
Yuan-Zhi Tan ◽  
...  
2017 ◽  
Vol 56 (12) ◽  
pp. 3280-3284 ◽  
Author(s):  
Ji Ma ◽  
Junzhi Liu ◽  
Martin Baumgarten ◽  
Yubin Fu ◽  
Yuan-Zhi Tan ◽  
...  

2021 ◽  
Author(s):  
Zhongxin Chen ◽  
Yuan Li ◽  
Wenqiang Li ◽  
Weiya Zhu ◽  
Miao Zeng ◽  
...  

The active materials of organic solar cells are widely recognized to show closed-shell singlet ground state and their electron spin resonance signals are attributed to the defects and impurities. Herein, we disclose the inherent open-shell singlet ground state of donors and the closed-shell structure of acceptors via the combination of variable temperature NMR, electron spin resonance, superconducting quantum interference device and theoretical calculation, providing a new perspective to understand the intrinsic molecular structure in organic solar cells.


1998 ◽  
Vol 8 (5) ◽  
pp. 1165-1172 ◽  
Author(s):  
Ll. Viadel ◽  
J. Carilla ◽  
E. Brillas ◽  
A. Labarta ◽  
L. Juliá

2021 ◽  
Author(s):  
Zhongxin Chen ◽  
Yuan Li ◽  
Wenqiang Li ◽  
Weiya Zhu ◽  
Miao Zeng ◽  
...  

The active materials of organic solar cells are widely recognized to show closed-shell singlet ground state and their electron spin resonance signals are attributed to the defects and impurities. Herein, we disclose the inherent open-shell singlet ground state of donors and the closed-shell structure of acceptors via the combination of variable temperature NMR, electron spin resonance, superconducting quantum interference device and theoretical calculation, providing a new perspective to understand the intrinsic molecular structure in organic solar cells.


2021 ◽  
Author(s):  
Omri Abarbanel ◽  
Julisa Rozon ◽  
Geoffrey Hutchison

Organic π-conjugated polymers with a triplet ground state have been the focus of recent research for their interesting and unique electronic properties, arising from the presence of the two unpaired electrons. These polymers are usually built from alternating electron-donating and electron-accepting monomer pairs which lower the HOMO-LUMO gap and yield a triplet state instead of the typical singlet ground state. In this paper we use density functional theory calculations to explore the design rules that govern the creation of a ground state triplet conjugated polymer, and find that a small HOMO-LUMO gap in the singlet state is the best predictor for the existence of a triplet ground state, compared to previous use of pro-quinoidal character. This work can accelerate the discovery of new stable triplet materials by reducing the computa- tional resources needed for electronic-state calculations and the number of potential candidates for synthesis.


2016 ◽  
Vol 138 (32) ◽  
pp. 10323-10330 ◽  
Author(s):  
Rui Huang ◽  
Hoa Phan ◽  
Tun Seng Herng ◽  
Pan Hu ◽  
Wangdong Zeng ◽  
...  

Nanoscale ◽  
2021 ◽  
Author(s):  
Lyudmila V. Begunovich ◽  
Artem V. Kuklin ◽  
Gleb V. Baryshnikov ◽  
Rashid R. Valiev ◽  
Hans Ågren

Tetraoxa[8]circulene based 2D COFs doped with s-block metals possess metallic properties. Doping with Ca results in superconductivity and an open-shell singlet ground state composed of two doublets.


2012 ◽  
Vol 11 (03) ◽  
pp. 599-609 ◽  
Author(s):  
YUHUA ZHOU ◽  
KAI TAN ◽  
XIN LU

The low-lying states of an organic donor-σ-acceptor dyad, i.e. tetrathiafulvalene-σ-tetracyano-p-quinodimethane (TTF-σ-TCNQ), in gas phase and in various solvents have been investigated by means of hybrid DFT calculations in combination with the conductor-like polarizable continuum model to describe solvent effects. It has been shown that the dyad, though preferring a closed-shell singlet ground state with an eclipsed conformation in gas phase, adopts the charge-separated zwitterionic states with an extended conformation (TTF+-σ-TCNQ-), i.e. open-shell singlet biradical ground state immediately followed by triplet biradical state, in polar solvent ( CH3CN and CH2Cl2 ) as a result of the intramolecular electron transfer (ET) stimulated by solvent polarization. The degree of such intramolecular ET is so strongly dependent on the polarity (dielectric constant) of solvent that the zwitterionic biradical states become more stable with respect to the closed-shell singlet state with increasing polarity of the solvent. As such, the dyad should show a higher ratio of biradicals in more polar solvent and/or at higher temperature and, hence, is chameleonic in nature.


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