The effect of molecular polarity on nem/catic phase stability in 12-vertex carboranes

Pecyna, Jacek; Denicola, Richard P.; Gray, Harrison; Ringstrand, Bryan; Kaszyński, Piotr

doi:10.1080/02678292.2014.911371

Cited by 17 publications

(32 citation statements)

References 24 publications

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“…63 Among a number of important topics not specifically covered are nonlinear optical materials, [166][167][168][169][170][171][172] liquid crystals, [173][174][175][176][177][178][179] and ionic liquids, 180 among others. I have barely scratched the surface of the burgeoning field of biomedical applications, on which a formidable literature has accumulated.…”

Section: Resultsmentioning

confidence: 99%

Carboranes in the chemist's toolbox

2015

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Once seldom encountered outside of a few laboratories, carboranes are now everywhere, playing a role in the development of a broad range of technologies encompassing organic synthesis, radionuclide handling, drug design, heat-resistant polymers, cancer therapy, nanomaterials, catalysis, metal-organic frameworks, molecular machines, batteries, electronic devices, and more. This perspective highlights selected examples in which the special attributes of carboranes and metallacarboranes are being exploited for targeted purposes in the laboratory and in the wider world.

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Section: Resultsmentioning

confidence: 99%

Carboranes in the chemist's toolbox

2015

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“…The T NI of the series of x O-PPyPMe compounds (230, 230, 220, 218, 211, and 207 °C for x = 3–8, respectively) at heating were comparable to those of n O-PPPyMe compounds (232.8, 232.9, 220.9, 217.7, 209.9, and 206.9 °C for n = 3–8, respectively). If the T NI was considered as an indicator of nematic phase stability [ 35 ], the nematic phase stabilities of the two series of compounds ( x O-PPyPMe and n O-PPPyMe) were nearly identical. In other words, nematic phase stability was independent of the bending position (the position of pyridine moiety) in the teraryl mesogenic core.…”

Section: Resultsmentioning

confidence: 99%

Effect of Pyridine on the Mesophase of Teraryl Liquid Crystals: A New Series of Nematic Liquid Crystals Named 2-(4-Alkoxybiphen-4′-yl)-5-methylpyridines

Chia

Huang

2016

IJMS

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A new series of teraryl 2-(4-alkoxybiphen-4′-yl)-5-methylpyridines (nO-PPPyMe, n = 3–8) nematic liquid crystal compounds, bearing a biphenylene core and a picoline terminus, were synthesized using a short two-step reaction, and overall yields between 34% and 38% were obtained. Spectral analysis results were in accordance with the expected structures. The thermotropic behavior of the teraryl liquid crystal compounds was investigated through polarized optical microscopy and differential scanning calorimetry. All compounds exhibited a solely enantiotropic nematic phase at the medium–high temperature range of 162.4–234.2 °C. Furthermore, the results for the nO-PPPyMe series were analyzed relative to three other compound series, mO-PPPyCN (m = 2–8), iO-PPQMe (i = 3–8) and xO-PPyPMe (x = 1–10). Consequently, the effect of pyridine on the mesophase of teraryl liquid crystals was demonstrated.

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“…Experiments with various amounts of NaOH demonstrated that at least three equivalents per one equivalent of the alcohol is required and five equivalents is optimum for the reaction to be completed overnight at 80 o C. Monitoring progress of these test reactions with stoichiometric amounts of reagents (4•HCl : 6[9]: NaOH, 1:1:5) with 1 H NMR spectroscopy demonstrated that within the first hour about 33% of 1 [9] is formed, which increases to 71% after an additional 2 h, but does not change significantly overnight.…”

Section: Synthesismentioning

confidence: 99%

“…There is a rapidly growing interest in 4-alkoxypyridines 1[n] (n ≥ 3) as intermediates for soft materials such as liquid crystals [1][2][3][4][5] (including polar, [6][7][8][9][10][11] ionic [12][13][14][15] and quadrupolar species, such as 2[n] 10 in Figure 1), molecular electronics, 16 bio-active derivatives, [17][18][19] and also for research on organometallic complexes, [2][3][4][20][21][22] weak intermolecular interactions, 1,5 and various other aspects of organic chemistry. [23][24][25] Some 4-alkoxypyridines 1[n] have been shown to exhibit biological activity, such as inhibition of cytochrome P-450-catalyzed aniline hydroxylation 26,27 or gastric antisecretory activity.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 4-alkoxypyridines as intermediates for zwitterionic liquid crystals

Hajhussein¹,

Abuzahra²,

Pietrzak³

et al. 2018

Arkivoc

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A series of 4-alkoxypyridines with n = 5-18 was obtained in typical yields of 75-80% by reacting 4-chloropyridine hydrochloride with the appropriate alcohol in DMSO in the presence of powdered NaOH. The reported synthesis is compared to other methods for preparation of 4-alkoxypyridines, and their uses are reviewed. 4-Tridecyloxypyridine is converted into the bis-zwitterionic derivative of [closo-B10H10] 2-, which exhibits liquid crystalline and soft crystalline phases. The solid-state structures of two pyridines and the biszwitterion are established by the single crystal XRD method. The effect of N-atom coordination on the pyridine ring geometry is investigated.

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The effect of molecular polarity on nem/catic phase stability in 12-vertex carboranes

Cited by 17 publications

References 24 publications

Carboranes in the chemist's toolbox

Carboranes in the chemist's toolbox

Effect of Pyridine on the Mesophase of Teraryl Liquid Crystals: A New Series of Nematic Liquid Crystals Named 2-(4-Alkoxybiphen-4′-yl)-5-methylpyridines

Synthesis of 4-alkoxypyridines as intermediates for zwitterionic liquid crystals

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