Nitroxides. LII. Synthesis and electron spin resonance studies of N,N'-dioxy-2,6-diazaadamantane, a symmetrical ground state triplet

1974 ◽  
Vol 96 (21) ◽  
pp. 6559-6568 ◽  
Author(s):  
Rose M. Dupeyre ◽  
Andre Rassat ◽  
Jacques Ronzaud
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.


2011 ◽  
Vol 109 (7) ◽  
pp. 07B104 ◽  
Author(s):  
M. Corti ◽  
L. Cattaneo ◽  
M. C. Mozzati ◽  
F. Borsa ◽  
Z. H. Jang ◽  
...  

1977 ◽  
Vol 55 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Amikam Reuveni ◽  
Vincenzo Malatesta ◽  
Bruce R. McGarvey

The synthesis, physical properties, and electron spin resonance of frozen solutions of CoTAAB(NO3)2 (TAAB = tetrabenzo[b,f,j,n] [1,5,9,13]tetraazacyclohexadecine) are reported. The spin Hamiltonian parameters were elucidated by simulation of spectra assuming axial g and 59Co hyperfine tensors and including nuclear quadrupole and Zeeman contributions. Electron spin resonance spectra in solvents such as methanol, acetone, and dimethylformamide are typical for a low spin complex (S = 1/2) and are nearly identical with [Formula: see text] and [Formula: see text]. In pyridine and quinoline a complex with a molar ratio solvent/ligand of 1:1 is formed with the solvent which gives [Formula: see text]and [Formula: see text] much closer to [Formula: see text]. In strong Lewis bases, such as piperidine, a 2:1 complex is formed and no esr signal is found. Evidence is presented to show that these 2:1 complexes with strong Lewis bases are S = 1/2 complexes with a low lying S = 3/2 state that is partially populated at room temperatures. This behaviour is accounted for in terms of a theory derived for a 2A1 ground state with a low lying quartet state which could become the ground state in strong basic solvents.


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.


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