5,8-Bis(1,3-dithiol-2-ylidene)-5,8-dihydroquinoxalines: novel electron donors with low oxidation potentials

1991 ◽  
pp. 1132 ◽  
Author(s):  
Yoshiro Yamashita ◽  
Shoji Tanaka ◽  
Kenichi Imaeda ◽  
Hiroo Inokuchi ◽  
Mizuka Sano
Keyword(s):  
Electron Donors ◽  
Oxidation Potentials

ChemInform Abstract: 5,8-Bis(1,3-dithiol-2-ylidene)-5,8-dihydroquinoxalines: Novel Electron Donors with Low Oxidation Potentials.

ChemInform ◽  
2010 ◽  
Vol 23 (11) ◽  
pp. no-no
Author(s):  
Y. YAMASHITA ◽  
S. TANAKA ◽  
K. IMAEDA ◽  
H. INOKUCHI ◽  
M. SANO
Keyword(s):  
Electron Donors ◽  
Oxidation Potentials

Photophysical studies of supramolecular triads involving zinc naphthalocyanines and pyridylfullerenes with a second electron donor

2006 ◽  
Vol 10 (09) ◽  
pp. 1156-1164 ◽  
Author(s):  
Mohamed E. El-Khouly ◽  
Yasuyuki Araki ◽  
Osamu Ito ◽  
Suresh Gadde ◽  
Melvin E. Zandler ◽  
...  
Keyword(s):  
Electron Donor ◽  
Transient Absorption ◽  
Binding Constants ◽  
Primary Electron ◽  
Electron Donors ◽  
Stable Complex ◽  
Axial Coordination ◽  
Spectral Technique ◽  
Oxidation Potentials ◽  
Donor Ability

Supramolecular triads composed of zinc naphthalocyanine ( ZnNc ) as an electron donor, pyridylfullerenes as primary electron acceptors, and either ferrocene ( Fc ) or N , N -dimethylaminophenyl ( DMA ) entities as second electron donors were constructed via metal-ligand axial coordination. The formation of the supramolecular triads was monitored using optical absorption methods and the measured binding constants revealed a moderately stable complex formation. The B3LYP/3-21G(*) optimized structures showed the disposition of the three entities of the triads to be in a linear fashion. The redox behavior of the different components was studied using cyclic voltammetry in o-dichlorobenzene containing (n- C 4 H 9)4 NClO 4. The donor ability evaluated from the oxidation potentials of the electron donors followed the trend: ZnNc < Fc < DMA . Efficient electron transfer from the excited singlet state of zinc naphthalocyanine to the fullerene entity was observed in all of the studied triads in o-dichlorobenzene by fluorescence quenching measurements. Clear evidence, that the charge-separation process formed the radical ions in the triads, was obtained from a nanosecond transient absorption spectral technique, indicating the contribution of the second electron donor in prolonging the charge-separated states.

Electrochemical Behaviour of trans-[FeH(CN)(dppe)2] Adducts

2003 ◽  
Vol 68 (9) ◽  
pp. 1663-1676 ◽  
Author(s):  
Sílvia S. P. R. Almeida ◽  
M. Fátima C. Guedes Da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Electronic Communication ◽  
Electrochemical Behaviour ◽  
Mixed Valence ◽  
Electron Donors ◽  
Dinuclear Complexes ◽  
Ligand Parameters ◽  
Reduction Processes ◽  
Oxidation Potentials

Electrochemical behaviour of various metallo cyano adducts of trans-[FeH(CN)(dppe)2], viz. the dinuclear complexes [FeH(dppe)2(μ-CN)PdCl2(PPh3)], [FeH(dppe)2(μ-CN)NiCl2(PCy3)], and trinuclear [{FeH(dppe)2(μ-CN)}2(ReOCl3)], [{FeH(dppe)2(μ-CN)}2PtCl(Ph)] and [{FeX(dppe)2(μ-CN)}2WCl3(OH)] (X = Cl or OH, dppe = 1,2-diphenylphosphinoethane, PCy3 = P(C6H11)3), as well as the benzoylisocyanide mononuclear adduct trans-[FeH(CNCOPh)- (dppe)2], is reported. All of them exhibit FeII/FeIII-based oxidations (which are reversible, except for trans-[FeH(CNCOPh)(dppe)2]). The metallocyanide bridges C≡N-Re-N≡C and C≡N-W-N≡C in [{FeH(dppe)2(μ-CN)}2(ReOCl3)] and [{FeX(dppe)2(μ-CN)}2WCl3(OH)], respectively, allow electronic communication between the iron centres, with possible generation of mixed-valence FeII/FeIII complexes whose comproportionation constant could be estimated in the former case. From the values of the measured oxidation potentials, the electrochemical PL and EL ligand parameters have been estimated for the metallocyanide ligands that were shown to behave as stronger net electron donors than organoisocyanides, although weaker than cyanide itself. Ligand-centred reduction processes were also observed to lead, in the cases of complexes trans-[FeH(CNCOPh)(dppe)2] (CNCOPh-based reduction) and [FeH(dppe)2(μ-CN)PdCl2(PPh3)] (PdII-based reduction in the CNPdCl2(PPh3)- metallocyanide ligand), to the dissociation of the adduct, with regeneration of the parent cyano complex trans-[FeH(CN)(dppe)2], thus reflecting the reductive decrease of the electrophilic (or Lewis acidic) character of the benzoyl and {PdCl2(PPh3)} groups.

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

The interaction of electron donors and acceptors

1964 ◽  
Vol 61 ◽  
pp. 20-38 ◽  
Author(s):  
Robert S. Mulliken
Keyword(s):  
Electron Donors

The Influence of Disintegration of Hard Coal Varieties of Different Metamorphism Grade on the Amount of Sorbed Ethane / Wpływ rozdrobnienia odmian węgla kamiennego o różnym stopniu metamorfizmu na ilości sorbowanego etanu

2013 ◽  
Vol 58 (2) ◽  
pp. 449-463 ◽  
Author(s):  
Mieczysław Żyła ◽  
Agnieszka Dudzińska ◽  
Janusz Cygankiewicz
Keyword(s):  
Sorption Isotherms ◽  
Electron Donors ◽  
Hard Coal ◽  
Coal Surface ◽  
Compact Layer ◽  
Compact Structure ◽  
Small Surface ◽  
Mining Works ◽  
The Impact ◽  
Content Of Oxygen

Ethane constitutes an explosive gas. It most often accompanies methane realizing during exploitation and mining works. In this paper the results of ethane sorption have been discussed on three grain classes of six selected hard coal samples collected from active Polish coalmines. On the basis of obtained results, it has been stated that the tested hard coals prove differentiated sorption power with reference to ethane. Te extreme amount of ethane is sorbed by low carbonized hard coal from “Jaworzno” coalmine. This sort of coal shows great porosity, and great content of oxygen and moisture. The least amount of ethane is sorbed by hard coal from “Sośnica” coalmine. This sort of coal possesses relatively a great deal of ash contents. Together with the process of coal disintegration, the amount of sorbed ethane increases for all tested coal samples. Between tested coals there are three medium carbonized samples collected from “Pniówek”, “Chwałowice” “Zofiówka” coalmines which are characterized by small surface values counted according to model BET from nitrogen sorption isotherms determined at the temperature of 77.5 K. The samples of these three coals prove the highest, from between tested coals, increase of ethane sorption occurring together with their disintegration. These samples disintegrated to 0,063-0,075 mm grain class sorb ethane in the amount corresponding with the sorption quantity of low carbonized coal from “Jaworzno” coalmine in 0.5-0.7 mm grain class. It should be marked that the low carbonized samples collected from “Jaworzno” and Wesoła” coalmines possess large specific surface and great porosity and belong to coal group of “loose” spatial structure. Regarding profusion of sorbed ethane on disintegrated medium carbonized samples from “Pniówek”, “Zofiówka”, “Chwałowice” coalmines it can be supposed that in the process of coal disintegration, breaking their “compact’ structure occurs. Loosened structure of medium carbonized coals results in increasing accessibility of ethane particles to sorption centres both electron donors and electron acceptors which are present on hard coal surface. The surface sorption centre increase may result in formation a compact layer of ethane particles on coal surface. In the formed layer, not only the strengths of vertical binding of ethane particles with the coal surface appear but also the impact of horizontal strengths appears which forms a compact layer of sorbed ethane particles. The surface layer of ethane particles may lead to explosion.

Sulfonamides Are an Overlooked Class of Electron Donors in Luminogenic Luciferins and Fluorescent Dyes

2018 ◽  
Author(s):  
Deepak K. Sharma ◽  
Spencer T. Adams ◽  
Kate L. Liebmann ◽  
Adam Choi ◽  
Stephen Miller
Keyword(s):  
Fluorescent Dyes ◽  
Bright Light ◽  
Firefly Luciferase ◽  
Electron Donors ◽  
Light Emitting

Many fluorophores, and all bright light-emitting substrates for firefly luciferase, contain hydroxyl or amine electron donors. Here we show that sulfonamides can serve as replacements for these canonical groups. Unlike “caged” carboxamides, sulfonamide analogues enable bioluminescence, and sulfonamidyl luciferins, coumarins, rhodols, and rhodamines are fluorescent in water. Sulfonamide donors thus have previously unappreciated potential to expand the functional repertoire of luminescent molecules.

Sign in / Sign up

Export Citation Format

Share Document