Deliberate Charge Conjugation Symmetry Breaking for π-Conjugated Electron Acceptor Design

2015 ◽  
Vol 119 (23) ◽  
pp. 12808-12814 ◽  
Author(s):  
Yongwoo Shin ◽  
Xi Lin
Keyword(s):  
Symmetry Breaking ◽  
Electron Acceptor ◽  
Charge Conjugation

Charge-conjugation symmetry breaking and the absorption spectra of polyphenylenes

1995 ◽  
Vol 51 (8) ◽  
pp. 5546-5549 ◽  
Author(s):  
Yu. N. Gartstein ◽  
M. J. Rice ◽  
E. M. Conwell
Keyword(s):  
Symmetry Breaking ◽  
Absorption Spectra ◽  
Charge Conjugation

Absorption spectroscopy of charged excitations in α-sexithiophene: evidence for charge conjugation symmetry breaking

1996 ◽  
Vol 210 (1-2) ◽  
pp. 229-234 ◽  
Author(s):  
P.A. Lane ◽  
X. Wei ◽  
Z.V. Vardeny ◽  
J. Poplawski ◽  
E. Ehrenfreund ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Absorption Spectroscopy ◽  
Charge Conjugation

scholarly journals Влияние асимметричного переноса зарядана ИК спектры возбужденных квадрупольных молекул

2020 ◽  
Vol 128 (11) ◽  
pp. 1585
Author(s):  
В.Г. Ткачёв ◽  
А.И. Иванов
Keyword(s):  
Experimental Data ◽  
Charge Transfer ◽  
Symmetry Breaking ◽  
Ir Spectra ◽  
Electron Donor ◽  
Electron Acceptor ◽  
Physical Interpretation

The influence of charge transfer symmetry breaking in excited quadrupole molecules of the form D-π-A-π-D or A-π-D-π-A, where A and D are the electron-acceptor and electron-donor groups, on non-stationary spectra of characteristic vibrations is studied. In the framework of the previously developed theory of symmetry breaking and its manifestations in non-stationary IR spectra, the types of possible changes in IR spectra with an increase in the degree of asymmetry of molecules are classified. A physical interpretation of the revealed regularities is presented and their comparison with the currently available experimental data is carried out.

The Role of Twisting in Driving Excited-State Symmetry Breaking and Enhanced Two-Photon Absorption in Quadrupolar Cationic Pyridinium Derivatives

2021 ◽  
Author(s):  
Alessio Cesaretti ◽  
Anna Spalletti ◽  
Fausto Elisei ◽  
Paolo FOGGI ◽  
Raimondo Germani ◽  
...  
Keyword(s):  
Excited State ◽  
Symmetry Breaking ◽  
Electron Acceptor ◽  
Electron Donors ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon

Two symmetric quadrupolar cationic push-pull compounds with a central electron-acceptor (N+-methylpyrydinium, A+) and different lateral electron-donors, (N,N-dimethylamino and N,N-diphenylamino, D) in a D-π-A+-π-D arrangement, were investigated together with their dipolar...

Charge-conjugation symmetry breaking in poly (phenylenevinylene) derivatives

1996 ◽  
Vol 78 (3) ◽  
pp. 183-186 ◽  
Author(s):  
Yu.N. Gartstein ◽  
M.J. Rice ◽  
E.M. Conwell
Keyword(s):  
Symmetry Breaking ◽  
Charge Conjugation

Symmetry breaking in convergent-beam diffraction

1989 ◽  
Vol 47 ◽  
pp. 480-481
Author(s):  
D.J. Eaglesham
Keyword(s):  
Symmetry Breaking ◽  
Point Group ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
Space Groups ◽  
Atomic Displacements ◽  
Small Probe ◽  
Phase Sensitive ◽  
Convergent Beam

Convergent Beam Electron Diffraction is now almost routinely used in the determination of the point- and space-groups of crystalline samples. In addition to its small-probe capability, CBED is also postulated to be more sensitive than X-ray diffraction in determining crystal symmetries. Multiple diffraction is phase-sensitive, so that the distinction between centro- and non-centro-symmetric space groups should be trivial in CBED: in addition, the stronger scattering of electrons may give a general increase in sensitivity to small atomic displacements. However, the sensitivity of CBED symmetry to the crystal point group has rarely been quantified, and CBED is also subject to symmetry-breaking due to local strains and inhomogeneities. The purpose of this paper is to classify the various types of symmetry-breaking, present calculations of the sensitivity, and illustrate symmetry-breaking by surface strains.CBED symmetry determinations usually proceed by determining the diffraction group along various zone axes, and hence finding the point group. The diffraction group can be found using either the intensity distribution in the discs

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

A Symmetry-Breaking Theory of False Pop Out

2011 ◽  
Author(s):  
Kimberley D. Orsten ◽  
Mary C. Portillo ◽  
James R. Pomerantz
Keyword(s):  
Symmetry Breaking
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