The Inductive Mechanism of Dipole Interaction and the Estimation of Molecular Dipole Moments

1941 ◽  
Vol 9 (8) ◽  
pp. 653-658 ◽  
Author(s):  
A. Edward Remick
Keyword(s):  
Dipole Moments ◽  
Dipole Interaction ◽  
Molecular Dipole ◽  
Inductive Mechanism

Precise measurement of molecular dipole moments with a tunable far-infrared Stark spectrometer: application to HOCl

1996 ◽  
Vol 13 (8) ◽  
pp. 1645 ◽  
Author(s):  
G. Modugno ◽  
P. De Natale ◽  
M. Bellini ◽  
M. Inguscio ◽  
G. Di Lonardo ◽  
...  
Keyword(s):  
Precise Measurement ◽  
Dipole Moments ◽  
Far Infrared ◽  
Molecular Dipole

scholarly journals Synthesis of 4-Chloro-1,3-Diazobenzene Bent-Cores Liquid Crystals and Characterizations of Their Mesogenic Behaviors and Photoisomerization Phenomena

2020 ◽  
Author(s):  
Jinying Lu ◽  
Zelong Zhang ◽  
Daoren Yan ◽  
Zhiyong Zhang ◽  
Jintao Guan ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Nematic Phase ◽  
Dipole Moments ◽  
Intermolecular Forces ◽  
Acetate Solution ◽  
Molecular Dipole ◽  
Practical Applications ◽  
Nematic Phases ◽  
Terminal Chain

<p></p><p>Azobenzene-based bent-core liquid crystals demonstrate a variety of mesomorphic behaviors and photochromic properties which are desirable for optical switching. Nowadays azobenzene-based bent-core liquid crystal (ABLC) compounds usually exhibit at least one of the following traits which are unfavorable for practical applications: (1) narrow temperature windows of nematic phases, (2) high phase transition temperature, and (3) long period of light stimulation to reach photostationary states. In this study, a series of ABLC compounds <b>4a–4g</b> were synthesized by adding azo functional groups and chlorine substituent to the central bent-cores to form 4-chloro-1,3-dizaophenylene bent-cores. These ABLC compounds were characterized by i. fourier-transform infrared spectroscopy (FTIR), <sup>1</sup>H and <sup>13</sup>C nuclear magnetic resonance (NMR), and mass spectrometry (MS) for their structures, ii. differential scanning calorimetry (DSC) and polarized optical microscopy (POM) for their mesogenic properties, and iii. ultraviolet–visible spectroscopy (UV-Vis) and POM for their photosensitivity. The experimental results show that all compounds exhibited broad temperature windows of mesogenic phases. In particular, compound <b>4c</b> showed a broad temperature window of 63.8 °C for nematic phase. Molecular simulations indicate that the molecular dipole moments of compounds <b>4a–4g</b> are closely associated with the temperatures of Sm – N phase transition and temperature ranges of nematic phases. In addition, simulation results reveal that the terminal alkyl chains exhibit a diphasic effect on the molecular polarity: extending the terminal chain can initially reduce and then increase the molecular dipole moments due to the severe structural disorder of overly extended terminal chain. These findings indicate that the intermolecular forces play a vital role in shaping the mesogenic behavior of ABLCs. Comprehensive characterizations of photochromatic properties show that <b>4c</b> was highly photosensitive and displayed rapid photoisomerization processes. At room temperature, compound <b>4c </b>dissolved in ethyl acetate solution can reach photostationary state in 10 seconds. At 95 °C, compound <b>4c</b> in nematic phase became isotropic liquid under UV-irradiation in 3 seconds due to the forward <i>trans – cis</i> photoisomerization and can be restored to be nematic under natural visible light in 5 seconds because of the backward <i>cis – trans</i> photoisomerization. This study linking the mechanistic details with mesogenic properties provides valuable insights to improve future design of azobenzene bent-core liquid crystals for practical applications especially in photonic applications.</p><p><br></p><p>Pertinent molecular structure files (mol2) can be downloaded from</p><p><a href="https://github.com/er1czz/ABLC">https://github.com/er1czz/ABLC</a><br></p><p></p>

scholarly journals Deep insight into reasons for the mechanoluminescence phenomenon of triphenylamine-substituted imidazoles and their distinct mechano-fluorochromic behaviours

RSC Advances ◽  
2020 ◽  
Vol 10 (39) ◽  
pp. 23187-23195 ◽  
Author(s):  
Xiao-Jing Liu ◽  
Guan-Lei Gao ◽  
Hao Jiang ◽  
Yan-Rong Jia ◽  
Min Xia
Keyword(s):  
Dipole Moments ◽  
Deep Insight ◽  
Molecular Dipole ◽  
Insight Into

Three imidazole crystals with high molecular dipole moments exhibit remarkable ML effects that are attributed to the formation of polar molecular couples in crystals. Imidazole and benzimidazole crystals are MFC-active, but phenanthrimidazole one is MFC-inactive.

Designed Formation of Nanocomposites via Dipole Interaction

2006 ◽  
Author(s):  
David Salac ◽  
Wei Lu
Keyword(s):  
Molecular Diffusion ◽  
Field Model ◽  
Dipole Moments ◽  
Phase Field Model ◽  
Dipole Interaction ◽  
Intermolecular Forces ◽  
Molecular Organization ◽  
Layer By Layer ◽  
Alignment Structure ◽  
Combined Actions

The formation of designed nanocomposites by multiple layers of adsorbate molecules is studied. We consider the presence of two types of molecules in each layer, which are characterized by different dipole moments. The nanostructures are characterized by the non-uniform distribution of the two molecules. A phase field model is developed to simulate the molecular diffusion and patterning under the combined actions of dipole moments, intermolecular forces, entropy, and external electric field. The study reveals self-alignment, structure conformation and the possibility to reduce the domain sizes via a layer by layer approach. It is also shown that the structure in a layer may define the roadway for molecules to travel on top it. This combined with electrodes embedded in the substrate gives much flexibility to guide the molecular organization and fabrication of designed nanocomposites.

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