Contrasting Behaviour of Exciplex Ensembles in the Diastereodifferentiating Paternò–Büchi Reaction of Chiral Cyanobenzoate with Naphthyl- and Phenylethenes on Direct or Charge-Transfer Excitation

2015 ◽  
Vol 68 (11) ◽  
pp. 1693 ◽  
Author(s):  
Keisuke Nagasaki ◽  
Yoshihisa Inoue ◽  
Tadashi Mori
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Charge Transfer Complex ◽  
Small Temperature ◽  
Acceptor Interaction ◽  
Subtle Change ◽  
Excited Species ◽  
Donor Acceptor ◽  
Charge Transfer Excitation ◽  
The Difference

The diastereodifferentiating Paternò–Büchi reaction of chiral cyanobenzoate with 1-(1-naphthyl)-1-phenylethene was compared with those with 1,1-diphenylethene on direct and charge-transfer excitations. By desymmetrization of the donor, four diastereomeric oxetane products were formed on photolysis in excellent combined yields. Increase in donor strength induced a stronger charge-transfer interaction both in ground and excited states. Thus, the difference in diastereoselectivities with two different excitation modes (i.e. direct versus charge-transfer) became less significant with a naphthyl derivative as donor. A subtle change of donor–acceptor interaction was shown to have profound effect on the nature of the excited-state complexes and thus the product (stereo)selectivities. Despite a small temperature dependence, an Eyring-type study on the diastereoselectivities confirmed that the excited charge-transfer complex is an excited species distinct from the conventional exciplex.

Complexation par transfert de charge de la chlorpromazine en présence d'iode; action thyroïdienne sécondaire de cette molécule

1984 ◽  
Vol 62 (9) ◽  
pp. 1807-1811 ◽  
Author(s):  
Anne-Catherine Absil ◽  
Jacques Buxeraud ◽  
Claude Raby
Keyword(s):  
Charge Transfer ◽  
Thermodynamic Parameters ◽  
Molecular Interaction ◽  
Electron Spectroscopy ◽  
Formation Constant ◽  
Charge Transfer Complex ◽  
Tertiary Amines ◽  
Acceptor Interaction ◽  
Donor Acceptor ◽  
A Charge

Molecular interaction between iodine and chlorpromazine is investigated by electron spectroscopy. Iodine forms a charge transfer complex with chlorpromazine, with 1:1 stoichiometry and of the n–σ type. The values of the formation constant (Kc at20 °C = 3166 ± 19 L mol−1) and thermodynamic parameters (ΔH0 = −11.22 ± 0.11 kcal mol−1, ΔS0 = −22.29 ± 0.38 cal mol−1 K−1) show a strong donor–acceptor interaction, comparable to that obtained with tertiary amines. The formation constant is compared to those obtained with antithyroid molecules. Chlorpromazine appears to have no effect on the intrathyroid cycle of iodine.

Homeotropic alignment through charge-transfer-induced columnar mesophase formation in an unsymmetrically substituted triphenylene derivative

2010 ◽  
Vol 82 (11) ◽  
pp. 1993-2003 ◽  
Author(s):  
Juanjuan Li ◽  
Zhiqun He ◽  
Huan Zhao ◽  
Hemant Gopee ◽  
Xiangfei Kong ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Mesophase Formation ◽  
Homeotropic Orientation ◽  
Donor Acceptor ◽  
Homeotropic Alignment ◽  
Spectroscopy Optical

An unsymmetrically substituted triphenylene, with two adjacent chloroethoxyethyl lateral flexible chains, was synthesized and characterized. Although this compound showed no mesomorphic behavior, it formed a donor–acceptor charge-transfer complex with 2,4,7-trinitrofluorenone (TNF). The resulting 1:1 complex has been investigated using UV–vis and IR spectroscopy, optical microscopy, thermal analysis, and X-ray diffraction. A columnar mesophase with hexagonal symmetry was found. More interestingly, this charge-transfer complex can be easily aligned on a glass surface in a homeotropic orientation, which is stable at room temperature (RT) and over a wide temperature range.

scholarly journals Rational Design of TADF Polymers Using a Donor-Acceptor Monomer with Enhanced TADF Efficiency Induced by the Energy Alignment of Charge Transfer and Local Triplet Excited States

2016 ◽  
Vol 4 (4) ◽  
pp. 597-607 ◽  
Author(s):  
Roberto S. Nobuyasu ◽  
Zhongjie Ren ◽  
Gareth C. Griffiths ◽  
Andrei S. Batsanov ◽  
Przemyslaw Data ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Rational Design ◽  
Donor Acceptor ◽  
Triplet Excited States

Charge Transfer Complexes of Aromatic Nitrocompounds with Disubstituted Naphthalenes. I.Spectroscopic Investigation of the Donor Behaviour of the 2,6- and 23-Dimethylnaphthalene

1984 ◽  
Vol 39 (12) ◽  
pp. 1274-1278 ◽  
Author(s):  
M. H. Abdel-Kader ◽  
R. M. Issa ◽  
M. M. Ayad ◽  
M. S. Abdel-Mottaleb
Keyword(s):  
Charge Transfer ◽  
Spectral Characteristics ◽  
Charge Transfer Complexes ◽  
Element Analysis ◽  
H Nmr ◽  
Aromatic Nitrocompounds ◽  
Donor Acceptor ◽  
The Difference ◽  
Donor Behaviour ◽  
Ct Complexes

The charge transfer complexes of 2,3- (I) and 2,6-Dimethylnaphthalenes (II) as electron donors with tri- and di-nitrobenzenes as electron acceptors are prepared and investigated by element analysis, IR. 1H nmr and electronic absorption spectroscopy. The results showed that I yields CT complexes of 1:1 type only while II is capable of forming 1 : 1 and 1 : 2 (donor: acceptor) compounds. The spectral characteristics of the CT complexes are pointed out and discussed. The difference in the donor behaviour between I and II is explained in the light of PPP-MO calculations.

scholarly journals Charge-transfer excited states in the donor/acceptor interface from large-scale GW calculations

2019 ◽  
Vol 151 (11) ◽  
pp. 114109 ◽  
Author(s):  
Takatoshi Fujita ◽  
Yoshifumi Noguchi ◽  
Takeo Hoshi
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Large Scale ◽  
Donor Acceptor

scholarly journals Fermi level pinned molecular donor/acceptor junctions: reduction of induced carrier density by interfacial charge transfer complexes

2020 ◽  
Vol 8 (43) ◽  
pp. 15199-15207
Author(s):  
Paul Beyer ◽  
Eduard Meister ◽  
Timo Florian ◽  
Alexander Generalov ◽  
Wolfgang Brütting ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Fermi Level ◽  
Carrier Density ◽  
Charge Transfer Complex ◽  
Charge Transfer Complexes ◽  
Interfacial Charge Transfer ◽  
Fermi Level Pinning ◽  
Donor Acceptor ◽  
Interfacial Charge

Charge transfer complex (CPX) formation at a donor–acceptor interface reduces the amount of Fermi-level pinning induced interfacial charge transfer.

scholarly journals Electronic interactions in 1D-π-assemblies from TLS analysis of thermal motion

2014 ◽  
Vol 70 (a1) ◽  
pp. C659-C659
Author(s):  
Sergey Lindeman ◽  
Marat Talipov ◽  
Shriya Wadumethrige ◽  
Oleg Dolomanov ◽  
Rajendra Rathore
Keyword(s):  
Charge Transfer ◽  
Graphical Representation ◽  
Electronic Materials ◽  
Variable Temperature ◽  
Supramolecular Assemblies ◽  
Thermal Motion ◽  
Theoretical Interpretation ◽  
Electronic Shell ◽  
Donor Acceptor ◽  
The Difference

Advanced features of TLS analysis within Olex2 program package allow for a detailed analysis of electronic redistribution in supramolecular systems. Particularly, the possibility of calculating TLS tensors in user-defined coordinate systems along with qualitative graphical representation of difference thermal motion are especially useful for analysis of atomic asphericity and intra- and inter-molecular electron redistribution. In addition, these features allow for a directional dynamic analysis of intermolecular motions from variable-temperature experiments. We explored the exciting new possibilities analyzing supramolecular assemblies closely resembling modern electronic materials for a series of electron donor-acceptor complexes and ion-radical salts based on aromatic octamethyl-anthracene and anti-aromatic octamethyl-biphenylene substrates. The difference TLS analysis revealed intimate details of chemical bond polarization and electronic shell expansion for acceptor components along with electronic shell contraction for donor components of the complexes indicative of intra- and intermolecular charge transfer. Also, the variable-temperature analysis of relative thermal motion of the complex components in the crystals revealed some widening of the potential-energy minima in direction of the electronic overlap as a result of intermolecular pi-orbital coupling both in charge-transfer and charge-resonance supramolecular assemblies. A theoretical interpretation of the observed peculiarities was undertaken supported by respective spectroscopic data.

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