Molecular dipole moments of hypochlorous acid and monochloramine from microwave spectroscopy

1971 ◽  
Vol 67 ◽  
pp. 601 ◽  
Author(s):  
D. G. Lister ◽  
D. J. Millen
Keyword(s):  
Hypochlorous Acid ◽  
Dipole Moments ◽  
Microwave Spectroscopy ◽  
Molecular Dipole

Some Molecular Dipole Moments Determined by Microwave Spectroscopy

1951 ◽  
Vol 82 (1) ◽  
pp. 95-95 ◽  
Author(s):  
James N. Schoolery ◽  
A. Harry Sharbaugh
Keyword(s):  
Dipole Moments ◽  
Microwave Spectroscopy ◽  
Molecular Dipole

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>

Preferred Rotameric Conformations of Isobutyraldehyde, Their Dipole Moments and Vibrationally Excited States by Microwave Spectroscopy

1986 ◽  
Vol 41 (3) ◽  
pp. 483-490 ◽  
Author(s):  
O. L. Stiefvater
Keyword(s):  
Oxygen Atom ◽  
Excited States ◽  
Ground State ◽  
Dipole Moments ◽  
Microwave Spectroscopy ◽  
Centrifugal Distortion ◽  
Gauche Conformation ◽  
Vibrationally Excited ◽  
Trans Conformation ◽  
Centrifugal Distortion Constants

The earlier prediction of the preferred and the less stable rotameric conformations of isobutyraldehyde, (CH3)2CHCHO, has been confirmed experimentally by microwave spectroscopy. The compound exists mainly in a gauche conformation, in which one of the methyl groups is eclipsed by the oxygen atom, and the less stable rotamer is the trans conformation, in which the oxygen atom eclipses the isopropyl hydrogen.Ground state rotational constants (in MHz) and centrifugal distortion constants (in kHz), together with dipole moments (in D), are:Rotation spectra due to three torsionally excited states of each rotamer have been identified, along with satellites arising from CH3 internal rotation and CC2 wagging.

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.

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