On the Role of Oxygen in the Formation of Electron Transmission Channels in Oligo(Phenylene Vinylene) Quinone Molecular Conductance

2010 ◽  
Vol 114 (28) ◽  
pp. 12341-12345 ◽  
Author(s):  
Nikolai Lebedev ◽  
Igor Griva ◽  
Scott A. Trammell ◽  
Gary S. Kedziora ◽  
Leonard M. Tender ◽  
...  
2011 ◽  
pp. 46-65 ◽  
Author(s):  
L. Polishchuk ◽  
R. Menyashev

The paper deals with economics of social capital which is defined as the capacity of society for collective action in pursuit of common good. Particular attention is paid to the interaction between social capital and formal institutions, and the impact of social capital on government efficiency. Structure of social capital and the dichotomy between its bonding and bridging forms are analyzed. Social capital measurement, its economic payoff, and transmission channels between social capital and economic outcomes are discussed. In the concluding section of the paper we summarize the results of our analysis of the role of social capital in economic conditions and welfare of Russian cities.


Nano Letters ◽  
2006 ◽  
Vol 6 (12) ◽  
pp. 2955-2958 ◽  
Author(s):  
Norton D. Lang ◽  
Cherie R. Kagan

2010 ◽  
Vol 247 (8) ◽  
pp. 1867-1870 ◽  
Author(s):  
Lionel Patrone ◽  
Jérémie Soullier ◽  
Pascal Martin

1995 ◽  
Vol 413 ◽  
Author(s):  
B. H. Cumpston ◽  
K. F. Jensen ◽  
F. Klavettert ◽  
E. G. J. Staring ◽  
R. C. J. E. Demand

ABSTRACTWe have identified excited-state singlet oxygen as a reactive intermediate in the solid state photo-oxidation of two poly(p-phenylene vinylene) (PPV) derivatives, poly(2,5-bis(5,6- cholestanoxy)-1,4-phenylene vinylene) (BCHA-PPV) and poly(2-methoxy,5-(2'-ethyl-hexoxy)- 1,4-phenylene vinylene) (MEH-PPV). Singlet oxygen is photosensitized via energy transfer from the polymer and undergoes 1,2-cycloaddition across the electron-rich vinyl double bond in the backbone of the polymer resulting in the formation of highly oxidized species such as esters. Volatile carbonyl species are also formed, and, consequently, the film thins. This degradation pathway occurs when the polymer film is exposed in air to light having energy above the bandgap of the polymer, from either a low-pressure UV mercury lamp or an Ar+ laser operating at 514 or 457 nm. Interestingly, the singlet oxygen reaction does not take place in model compounds with similar structures such as trans-stilbene. In an effort to understand which properties of the polymer make it susceptible to singlet oxygen attack, we have studied the effect of conjugation length and side groups on the reactivity of thin polymer films. Specifically, the role of electron withdrawing groups, steric protection of the vinyl double bond, and conjugation length effects have been investigated using both FrIR spectroscopy and semi-empirical computational chemistry calculations.


2020 ◽  
Author(s):  
Ashima Bajaj ◽  
Prabhleen Kaur ◽  
Aakanksha Sud ◽  
Marco Berritta ◽  
Md. Ehesan Ali

The molecular topology in the single-molecular nano-junctions through which the de Broglie wave propagates plays a crucial role in controlling the molecular conductance. The enhancement and reduction of the conductance due to constructive and destructive Quantum Interference (QI) in para and meta connected molecules respectively has already been well established. Herein, we investigated the influence of QI on spin transport in the molecular junctions containing organic radicals as magnetic centres. The role of the localized spins on the QI as well as on spin filtering capability is investigated employing density functional theory in combination with non-equilibrium Green's function (NEGF-DFT) techniques. Various organic radicals including nitroxide (NO), phenoxy (PO) and methyl (CH2) radicals attached to the central benzene ring of pentacene with different terminal connections (para and meta) to gold electrodes are examined. Due to more obvious QI effects, para connected pentacene is found to be more conductive than meta one. Surprisingly, on incorporating a radical centre, along with spin filtering, a significant quenching of QI effects is observed which manifests itself in such a way that the conductance of meta coupled radicals is found to be more than para by two orders of magnitude. The decoherence induced by radical centre is analysed and discussed in terms of spin-spin coupling of radical's unpaired electron with the tunneling electrons.<br>


2020 ◽  
Author(s):  
Ashima Bajaj ◽  
Prabhleen Kaur ◽  
Aakanksha Sud ◽  
Marco Berritta ◽  
Md. Ehesan Ali

The molecular topology in the single-molecular nano-junctions through which the de Broglie wave propagates plays a crucial role in controlling the molecular conductance. The enhancement and reduction of the conductance due to constructive and destructive Quantum Interference (QI) in para and meta connected molecules respectively has already been well established. Herein, we investigated the influence of QI on spin transport in the molecular junctions containing organic radicals as magnetic centres. The role of the localized spins on the QI as well as on spin filtering capability is investigated employing density functional theory in combination with non-equilibrium Green's function (NEGF-DFT) techniques. Various organic radicals including nitroxide (NO), phenoxy (PO) and methyl (CH2) radicals attached to the central benzene ring of pentacene with different terminal connections (para and meta) to gold electrodes are examined. Due to more obvious QI effects, para connected pentacene is found to be more conductive than meta one. Surprisingly, on incorporating a radical centre, along with spin filtering, a significant quenching of QI effects is observed which manifests itself in such a way that the conductance of meta coupled radicals is found to be more than para by two orders of magnitude. The decoherence induced by radical centre is analysed and discussed in terms of spin-spin coupling of radical's unpaired electron with the tunneling electrons.<br>


2021 ◽  
Author(s):  
Hashem Mohammad ◽  
Busra Demir ◽  
Caglanaz Akin ◽  
Binquan Luan ◽  
Joshua Hihath ◽  
...  

Intercalating ds-DNA/RNA with small molecules can play an essential role in controlling the electron transmission probability for molecular electronics applications such as biosensors, single-molecule transistors, and data storage. However, its...


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