Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O<sub>2</sub>. Electrons are fermions with a quantum spin number<em> s</em> o...Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O<sub>2</sub>. Electrons are fermions with a quantum spin number<em> s</em> of 1/2<span style="white-space:nowrap;"><em><span style="white-space:nowrap;">ħ</span></em></span>. An orbital containing a single electron with <em>s</em> = 1/2 is fermionic. Orbitals can contain a maximum of two electrons with antiparallel spins,<em> i.e.</em>, spin magnetic quantum numbers <em>m</em><sub><em>s</em></sub> of 1/2 and -1/2. An orbital filled by an electron couple has <em>s</em> = 0 and bosonic character. The multiplicity of a reactant is defined as |2(<em>S</em>)| + 1 where <em>S</em> is the total spin quantum number. The Wigner spin conservation rules state that multiplicity is conserved. The transmission coefficient <em>κ</em> of absolute reaction rate theory also indicates the necessity for spin conservation. Burning is fermionic combustion that occurs when sufficient energy is applied to a bosonic molecule to cause homolytic bond cleavage yielding fermionic products capable of reaction with the bifermionic frontier orbitals of triplet multiplicity O<sub>2</sub>. Neutrophil leucocytes kill microorganisms by bosonic combustion and employ two mechanisms for changing the multiplicity of O<sub>2</sub> from triplet to singlet. Microorganisms, composed of bosonic singlet multiplicity molecules, do not directly react with bifermionic O<sub>2</sub>, but are highly susceptible to electrophilic attack by bosonic electronically excited singlet molecular oxygen (<span style="white-space:nowrap;"><sup>1</sup>O<sub>2</sub><sup style="margin-left:-10px;">*</sup></span><span style="font-size:10px;white-space:nowrap;">).</span> Hydride ion (H<sup>-</sup>) transfer is the common mode of cytoplasmic redox metabolism. Bosonic transfer of an orbital electron couple protects from damage by obviating fermionic reaction with bifermionic O<sub>2</sub>. Bosonic coupled electron transfer raises the consideration that quantum tunneling might be involved in facilitating such redox transfer.展开更多
The dependence of the molecular weights on the concentration of reactants in the polymerization of acrylonitrile initiated by vanadium (V)-thiourea redox system has been investigated. It was found that the molecular w...The dependence of the molecular weights on the concentration of reactants in the polymerization of acrylonitrile initiated by vanadium (V)-thiourea redox system has been investigated. It was found that the molecular weights of the polymer change nonlinearly with increasing concentrations of nitric acid and thiourea. Probably, the composition of the complexes exert a great influence on the chain initiation and termination. The reaction of 'complextermination' gives rise to the decrease of the molecular weights markedly while the concentrations of thiourea and vanadium (V)in the range from one to three molar ratios.展开更多
Molecular wires with tetrathiafulvalene （TTF） as redox center were synthesized and characterized. UV-vis spectra and cyclic voltammetry showed these wires had good reversible redox behavior under ambient conditions ...Molecular wires with tetrathiafulvalene （TTF） as redox center were synthesized and characterized. UV-vis spectra and cyclic voltammetry showed these wires had good reversible redox behavior under ambient conditions and their HOMO energy levels （--5.0 eV） matched well with the Fermi level of Au （--5.1 eV）.展开更多
Precise control over the photoluminescence（PL） of single quantum dots（QDs） is important for their practical applications. We show that the PL of individual Cd Se/Zn S core/shell QDs can be effectively enhanced and...Precise control over the photoluminescence（PL） of single quantum dots（QDs） is important for their practical applications. We show that the PL of individual Cd Se/Zn S core/shell QDs can be effectively enhanced and continuously modulated by electrochemically manipulating the electron transfer（ET） between the QDs and the attached redox-active ligands such as 2-mercaptoethanol（BME）. We found that i） the ET from BME to the QDs＇ surface trap states suppresses the blinking of the QDs, ii） the ET from the QDs＇ conduction band to the oxidization product results in dimmed PL when BME is oxidized,and iii） further oxidization of BME results in a significant PL brightening. The single particle measurements help us unveil the important features hidden in ensemble measurements and understand the underlying mechanism of the PL modulation.The results also suggest a simple yet efficient method to produce bright and non-blinking QDs and offer opportunities for further development of high resolution fluorescent bioimaging and nanodevices.展开更多
Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared...Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared with the catholyte due to the labile properties of redox mediators at low potentials. Here, we report a new strategy that exploits high concentration organic lithium metal solution as a robust and energetic anolyte. The solution formed by dissolving metallic lithium with biphenyl （BP） in tetraethylene glycol dimethyl ether （TEGDME） presents a redox potential of 0.39V versus Li/Li＋, and a concentration up to 2 M. When coupled with a redox-targeted LiFePO4 catholyte system, the constructed redox flow lithium battery full cell delivers a ceil voltage of 3.0V and presents reasonably good cycling performance.展开更多
文摘Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O<sub>2</sub>. Electrons are fermions with a quantum spin number<em> s</em> of 1/2<span style="white-space:nowrap;"><em><span style="white-space:nowrap;">ħ</span></em></span>. An orbital containing a single electron with <em>s</em> = 1/2 is fermionic. Orbitals can contain a maximum of two electrons with antiparallel spins,<em> i.e.</em>, spin magnetic quantum numbers <em>m</em><sub><em>s</em></sub> of 1/2 and -1/2. An orbital filled by an electron couple has <em>s</em> = 0 and bosonic character. The multiplicity of a reactant is defined as |2(<em>S</em>)| + 1 where <em>S</em> is the total spin quantum number. The Wigner spin conservation rules state that multiplicity is conserved. The transmission coefficient <em>κ</em> of absolute reaction rate theory also indicates the necessity for spin conservation. Burning is fermionic combustion that occurs when sufficient energy is applied to a bosonic molecule to cause homolytic bond cleavage yielding fermionic products capable of reaction with the bifermionic frontier orbitals of triplet multiplicity O<sub>2</sub>. Neutrophil leucocytes kill microorganisms by bosonic combustion and employ two mechanisms for changing the multiplicity of O<sub>2</sub> from triplet to singlet. Microorganisms, composed of bosonic singlet multiplicity molecules, do not directly react with bifermionic O<sub>2</sub>, but are highly susceptible to electrophilic attack by bosonic electronically excited singlet molecular oxygen (<span style="white-space:nowrap;"><sup>1</sup>O<sub>2</sub><sup style="margin-left:-10px;">*</sup></span><span style="font-size:10px;white-space:nowrap;">).</span> Hydride ion (H<sup>-</sup>) transfer is the common mode of cytoplasmic redox metabolism. Bosonic transfer of an orbital electron couple protects from damage by obviating fermionic reaction with bifermionic O<sub>2</sub>. Bosonic coupled electron transfer raises the consideration that quantum tunneling might be involved in facilitating such redox transfer.
文摘The dependence of the molecular weights on the concentration of reactants in the polymerization of acrylonitrile initiated by vanadium (V)-thiourea redox system has been investigated. It was found that the molecular weights of the polymer change nonlinearly with increasing concentrations of nitric acid and thiourea. Probably, the composition of the complexes exert a great influence on the chain initiation and termination. The reaction of 'complextermination' gives rise to the decrease of the molecular weights markedly while the concentrations of thiourea and vanadium (V)in the range from one to three molar ratios.
基金supported by National Natural Sciences Foundation of China (Nos.20402015,60771031).
文摘Molecular wires with tetrathiafulvalene （TTF） as redox center were synthesized and characterized. UV-vis spectra and cyclic voltammetry showed these wires had good reversible redox behavior under ambient conditions and their HOMO energy levels （--5.0 eV） matched well with the Fermi level of Au （--5.1 eV）.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10904164,61275192,and 11104328)
文摘Precise control over the photoluminescence（PL） of single quantum dots（QDs） is important for their practical applications. We show that the PL of individual Cd Se/Zn S core/shell QDs can be effectively enhanced and continuously modulated by electrochemically manipulating the electron transfer（ET） between the QDs and the attached redox-active ligands such as 2-mercaptoethanol（BME）. We found that i） the ET from BME to the QDs＇ surface trap states suppresses the blinking of the QDs, ii） the ET from the QDs＇ conduction band to the oxidization product results in dimmed PL when BME is oxidized,and iii） further oxidization of BME results in a significant PL brightening. The single particle measurements help us unveil the important features hidden in ensemble measurements and understand the underlying mechanism of the PL modulation.The results also suggest a simple yet efficient method to produce bright and non-blinking QDs and offer opportunities for further development of high resolution fluorescent bioimaging and nanodevices.
基金financial support by the Energy Market Authority, Singapore under its Energy Innovation Research Programme-Energy Storage (NRF2015EWT-EIRP002)
文摘Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared with the catholyte due to the labile properties of redox mediators at low potentials. Here, we report a new strategy that exploits high concentration organic lithium metal solution as a robust and energetic anolyte. The solution formed by dissolving metallic lithium with biphenyl （BP） in tetraethylene glycol dimethyl ether （TEGDME） presents a redox potential of 0.39V versus Li/Li＋, and a concentration up to 2 M. When coupled with a redox-targeted LiFePO4 catholyte system, the constructed redox flow lithium battery full cell delivers a ceil voltage of 3.0V and presents reasonably good cycling performance.
