scholarly journals Exploration of the Photocatalytic Cycle for Sacrificial Hydrogen Evolution by Conjugated Polymers Containing Heteroatoms

2021 ◽  
Author(s):  
Andrew Prentice ◽  
Martijn Zwijnenburg
Keyword(s):  
Hydrogen Bond ◽  
Conjugated Polymers ◽  
Hydrogen Evolution ◽  
Noble Metal ◽  
Bond Formation ◽  
Metal Particles ◽  
Polymer Composition ◽  
Hydrogen Bond Formation ◽  
Co Catalyst ◽  
Co Catalysts

We analyze the photocatalytic activity of heteroatom containing linear conjugated polymers for sacrificial hydrogen evolution using a recently proposed photocatalytic cycle. We find that the thermodynamic barrier to electron transfer, relevant both in the presence and absence of noble metal co-catalysts, changes with polymer composition, reducing upon going from electron-rich to electron-poor polymers, and disappearing completely for the most electron-poor polymers in a water rich environment. We discuss how the latter is probably the reason why electron-poor polymers are generally more active for sacrificial hydrogen evolution than their electron-rich counterparts. We also study the barrier to hydrogen-hydrogen bond formation on the polymer rather than the co-catalyst and find that it too changes with composition but is always, at least for the polymer studied here, much larger than that experimentally reported for platinum. Therefore, it is expected that in the presence of any noble metal particles these will act as the site of hydrogen evolution.

scholarly journals Hydrogen Evolution by Polymer Photocatalysts; a Possible Photocatalytic Cycle

2021 ◽  
Author(s):  
Andrew Prentice ◽  
Martijn Zwijnenburg
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfer ◽  
Hydrogen Evolution ◽  
Noble Metal ◽  
Electron Donor ◽  
Molecular Hydrogen ◽  
Bond Formation ◽  
Hydrogen Bond Formation ◽  
Co Catalyst ◽  
Polymer Properties

<div> <div> <div> <p>We propose, supported by ab-initio calculations, a possible photocatalytic cycle for hydrogen evolution by a prototypical polymer photocatalyst, poly(p-phenylene), in the presence of a sacrificial electron donor. As part of that cycle we also introduce a family of related sites on the polymer that in the absence of a noble metal co-catalyst can facilitate the evolution of molecular hydrogen when the polymer is illuminated. The bottlenecks for hydrogen evolution, electron transfer from the sacrificial electron donor and hydrogen-hydrogen bond formation, are discussed, as well as how they could potentially be improved by tuning the polymer properties and how they change in the presence of a noble-metal co-catalyst. </p> </div> </div> </div>

scholarly journals Hydrogen Evolution by Polymer Photocatalysts; a Possible Photocatalytic Cycle

2021 ◽  
Author(s):  
Andrew Prentice ◽  
Martijn Zwijnenburg
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfer ◽  
Hydrogen Evolution ◽  
Noble Metal ◽  
Electron Donor ◽  
Molecular Hydrogen ◽  
Bond Formation ◽  
Hydrogen Bond Formation ◽  
Co Catalyst ◽  
Polymer Properties

<div> <div> <div> <p>We propose, supported by ab-initio calculations, a possible photocatalytic cycle for hydrogen evolution by a prototypical polymer photocatalyst, poly(p-phenylene), in the presence of a sacrificial electron donor. As part of that cycle we also introduce a family of related sites on the polymer that in the absence of a noble metal co-catalyst can facilitate the evolution of molecular hydrogen when the polymer is illuminated. The bottlenecks for hydrogen evolution, electron transfer from the sacrificial electron donor and hydrogen-hydrogen bond formation, are discussed, as well as how they could potentially be improved by tuning the polymer properties and how they change in the presence of a noble-metal co-catalyst. </p> </div> </div> </div>

scholarly journals Hydrogen Evolution by Polymer Photocatalysts; a Possible Photocatalytic Cycle

2021 ◽  
Author(s):  
Andrew Prentice ◽  
Martijn Zwijnenburg
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfer ◽  
Hydrogen Evolution ◽  
Noble Metal ◽  
Electron Donor ◽  
Molecular Hydrogen ◽  
Bond Formation ◽  
Hydrogen Bond Formation ◽  
Co Catalyst ◽  
Polymer Properties

<div> <div> <div> <p>We propose, supported by ab-initio calculations, a possible photocatalytic cycle for hydrogen evolution by a prototypical polymer photocatalyst, poly(p-phenylene), in the presence of a sacrificial electron donor. As part of that cycle we also introduce a family of related sites on the polymer that in the absence of a noble metal co-catalyst can facilitate the evolution of molecular hydrogen when the polymer is illuminated. The bottlenecks for hydrogen evolution, electron transfer from the sacrificial electron donor and hydrogen-hydrogen bond formation, are discussed, as well as how they could potentially be improved by tuning the polymer properties and how they change in the presence of a noble-metal co-catalyst. </p> </div> </div> </div>

Vapochromism induced by intermolecular electron transfer coupled with hydrogen-bond formation in zinc dithiolene complex

2020 ◽  
Vol 8 (42) ◽  
pp. 14939-14947
Author(s):  
So Yokomori ◽  
Shun Dekura ◽  
Tomoko Fujino ◽  
Mitsuaki Kawamura ◽  
Taisuke Ozaki ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfer ◽  
Bond Formation ◽  
Intermolecular Electron Transfer ◽  
Hydrogen Bond Formation ◽  
Complex Crystal

A novel vapochromic mechanism by intermolecular electron transfer coupled with hydrogen-bond formation was realized in a zinc dithiolene complex crystal.

Theoretical analysis of the (HNO)2, (HNO···HNS), and (HNS)2 dimers — A case of red and blue shifts of N–H stretching frequency

2010 ◽  
Vol 88 (8) ◽  
pp. 849-857 ◽  
Author(s):  
Nguyen Tien Trung ◽  
Tran Thanh Hue ◽  
Minh Tho Nguyen
Keyword(s):  
Hydrogen Bond ◽  
Quantum Chemical ◽  
Bond Formation ◽  
Blue Shift ◽  
Proton Donor ◽  
Basis Sets ◽  
Coupled Cluster ◽  
Hydrogen Bond Formation ◽  
Length Contraction ◽  
Moller Plesset

The hydrogen-bonded interactions in the simple (HNZ)2 dimers, with Z = O and S, were investigated using quantum chemical calculations with the second-order Møller–Plesset perturbation (MP2), coupled-cluster with single, double (CCSD), and triple excitations (CCSD(T)) methods in conjunction with the 6-311++G(2d,2p), aug-cc-pVDZ, and aug-cc-pVTZ basis sets. Six-membered cyclic structures were found to be stable complexes for the dimers (HNO)2, (HNS)2, and (HNO–HNS). The pair (HNS)2 has the largest complexation energy (–11 kJ/mol), and (HNO)2 the smallest one (–9 kJ/mol). A bond length contraction and a frequency blue shift of the N–H bond simultaneously occur upon hydrogen bond formation of the N–H···S type, which has rarely been observed before. The stronger the intramolecular hyperconjugation and the lower the polarization of the X–H bond involved as proton donor in the hydrogen bond, the more predominant is the formation of a blue-shifting hydrogen bond.

Internal Hydrogen Bond Formation in a syn-Hydroxyepoxide

Science ◽  
1982 ◽  
Vol 215 (4533) ◽  
pp. 695-696 ◽  
Author(s):  
J. P. GLUSKER ◽  
D. E. ZACHARIAS ◽  
D. L. WHALEN ◽  
S. FRIEDMAN ◽  
T. M. POHL
Keyword(s):  
Hydrogen Bond ◽  
Bond Formation ◽  
Hydrogen Bond Formation ◽  
Internal Hydrogen ◽  
Internal Hydrogen Bond

Influence of Hydrogen Bond Formation on the Photophysics ofN-(2,6-Dimethylphenyl)-2,3-naphthalimide

2004 ◽  
Vol 108 (19) ◽  
pp. 4357-4364 ◽  
Author(s):  
Attila Demeter ◽  
László Ravasz ◽  
Tibor Bérces
Keyword(s):  
Hydrogen Bond ◽  
Bond Formation ◽  
Hydrogen Bond Formation
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