Liquid Cis Research Articles

Thermal Conductivity of Liquid cis- and trans-Isomers of Hyrofluorochlorine Derivatives of Olefins on the Saturation Line

Thermal Conductivity of Liquid cis- and trans-Isomers of Hyrofluorochlorine Derivatives of Olefins on the Saturation Line

Healable azopolymer coatings with photoinduced reversible solid-to-liquid transitions for trenchless rehabilitation of pipelines

The development of healable polymers is crucial for the maintenance of underground pipeline systems during trenchless rehabilitation. While photocurable resins are commercial materials for this purpose, we introduce an innovative option: azobenzene-containing polymers (azopolymers) with photoinduced reversible solid-to-liquid transitions. The newly developed azopolymer comprises a methacrylate backbone and side chains incorporating hexyl spacers, azobenzene moieties, and dodecyl tails. We compared the thermal stability, efficiency of photoinduced solid-to-liquid transition, and adhesive strength among azopolymers with varying molecular weights. Subsequently, we identified the most suitable azopolymer for PVC pipe lining. The robust trans azopolymer inner layer maintains a solid state at ambient temperatures. Upon pipe damage, UV irradiation triggers trans-to-cis isomerization, leading to the conversion of the solid trans azopolymer into a liquid cis state. This flowing cis azopolymer effectively repairs cracks and can be reverted to its trans isomer via visible light irradiation or thermal relaxation. Unlike commercial photocurable resins, the developed azopolymers offer the advantage of multiple repair cycles. This study highlights the potential of azopolymers with photoinduced reversible solid-to-liquid transitions as innovative healable materials in trenchless rehabilitation technology.

Polyacrylate Backbone Promotes Photoinduced Reversible Solid-To-Liquid Transitions of Azobenzene-Containing Polymers

The development of polymers with efficient photoinduced reversible solid-to-liquid transitions is desirable for the design of healable materials, reconfigurable devices, and switchable adhesives. Herein, we demonstrate that an azobenzene-containing polyacrylate P-H exhibits more efficient photoinduced reversible solid-to-liquid transitions than its polymethacrylate analogue P-Me. The side chain of P-H or P-Me contains a hexamethylene spacer, a photoresponsive azobenzene group, and an n-decyl tail. Both P-H and P-Me show reversible cis–trans photoisomerization. Solid transP-H and P-Me change to liquid cis ones via UV-light-induced trans-to-cis isomerization; liquid cisP-H and P-Me revert to solid trans ones via visible-light-induced cis-to-trans back isomerization. Differential scanning calorimetry and rheology measurements revealed that photoinduced reversible solid-to-liquid transitions occur because P-H and P-Me have photoswitchable glass transition temperatures. Although P-Me exhibits a slightly faster rate for trans-to-cis photoisomerization than P-H due to fewer aggregates in solid state, cisP-H flows 20 times faster than cisP-Me because P-H has a more flexible polymer backbone. The low viscosity of cisP-H makes photoinduced solid-to-liquid transition efficient and enables the design of rapidly healable coatings. Our study shows that the design of a flexible backbone is a new strategy to develop rapidly healable polymers with more efficient photoinduced solid-to-liquid transitions.

Photoswitchable Adhesives Using Azobenzene-Containing Materials.

Photoinduced reversible solid-to-liquid transitions of azobenzene-containing materials can control adhesion. Photoswitchable adhesives based on azobenzene-containing small molecules and polymers are under intense investigation. The melting points or glass transition temperatures of such azobenzene-containing materials in trans and cis forms are above and below room temperature, respectively. Photoswitching of these materials results in reversible trans-cis isomerization and solid-to-liquid transitions. The solid trans azobenzene-containing materials have strong adhesion and the liquid cis azobenzene-containing materials have weaker adhesion. In this Minireview, we introduce adhesives based on azobenzene-containing small molecules and polymers. The remaining challenges and perspectives in the field of photoswitchable adhesives using azobenzene-containing materials are also discussed.

Thermodynamic characteristics of phase conversion of structural isomers for volatile complex of ruthenium (III) trifluoroacetylacetonate

The comprehensive analysis of volatile β-diketonate compound—ruthenium(III) trifruoroacetylacetonate (Ru(tfac)3)—was carried out. By means of flow method in quasi-equilibrium conditions and static method the temperature dependencies of saturated vapor pressure have been measured over solid and liquid cis- and trans-modifications of Ru(tfac)3 and isomer mixture. The thermodynamic characteristics of sublimation, evaporation, melting, and phase conversion have been calculated for structural isomers. Also by differential-scanning calorimetry the temperature meanings and the thermodynamic characteristics of melting have been determined for individual isomers of Ru(tfac)3 and their mixtures. By XRD the structures for cis- and trans-modifications have been determined. Both structures consist of neutral molecules arranged in pseudo layers.

Synthesis and Characterization of the First Liquid Single-Source Precursors for the Deposition of Ternary Chalcopyrite (CuInS2) Thin Film Materials

Molecular engineering of ternary single source precursors based on the [{PBu3}2Cu(SR')2In(SR')2] architecture have afforded the first liquid CIS ternary single source precursors (when R = Et, n-Pr), which are suitable for low temperature deposition (< 350 C). Thermogravimetric analyses (TGA) and modulated-differential scanning calorimetry (DSC) confirm their liquid phase and reduced stability. X-ray diffraction studies, energy dispersive analyzer (EDS), and scanning electron microscopy (SEM) support the formation of the single-phase chalcopyrite CuInS2 at low temperatures.

Reversible Reactions of Cycloalkane Solvent Holes. 2. Scavenging of cis- and trans-Decalin•+ by Benzene

Solvent holes in liquid cis- and trans-decalin form metastable complexes with benzene, which are probably solvation complexes of monomer radical cations of benzene. At 25 °C, the rate constants of formation of the complexes are, for trans- and cis-decalin respectively 1.1 × 1011 and 3.6 × 1010 M-1 s-1, and the natural lifetime of the complex is 7 ns for trans- and 50 ns for cis-decalin. Thermodynamic potentials for the complexation are determined. The heat of the complex formation is ≈−26 kJ/mol for trans- and ≈−18 kJ/mol for cis-decalin. In cis-decalin, the complexes are more stable because of near-zero entropy of the complex formation. The complex decays by proton or H atom transfer with activation energy ≈10 kJ/mol (which yields a benzonium cation) or in a reactive encounter with a second benzene molecule (which yields a benzene dimer cation). Laser excitation of the dimer cation with a 1.165- or 2.33 eV photon causes valence band electron transfer and injection of a free solvent hole.

ChemInform Abstract: Singlet and Triplet Excited‐State Formation in High‐Energy Electron Tracks in Liquid cis‐ and trans‐Decalin as Studied by Product Formation in Radiolysis and Photolysis.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Singlet and triplet excited-state formation in high-energy electron tracks in liquid cis- and trans-decalin as studied by product formation in radiolysis and photolysis

The yields of products formed as a result of irradiation of liquid cis- and trans-decalin with γ-rays and 3 MeV electrons as well as with 7.6 eV photons have been determined by means of gas–liquid chromatography (GLC). The major products for both cis- and trans-decalin are hydrogen, unsaturated C10 products and dimers; in the case of cis-decalin, cis–trans isomerization takes place via a chain reaction. Singlet and triplet excited states are formed by direct excitation and by charge recombination in the tracks of high-energy electrons. The product formation resulting from the singlets is determined by the photolysis. From a knowledge of the total yield of singlets from the radiolysis, the contribution of the singlet excited states to product formation during radiolysis is calculated and the remaining products are assigned to the triplets.For the sum of the yields of singlets and triplets a value of 6.4 (100 eV)–1(= 6.6 × 10–7 mol J–1) is found for cis-decalin and 6.0 (100 eV)–1(= 6.2 × 10–7 mol J–1) for trans-decalin and for the singlet fractions 0.53 and 0.47 in cis- and trans-decalin, respectively. The probability of C—H bond breakage in the singlet and triplet states is 0.42 and 0.82, respectively, for cis-decalin and 0.50 and 0.94, respectively, for trans-decalin.

Holes in hydrocarbons

Experimental evidence shows that rapid transfer of charge between parent positive ions and neutral molecules in liquid cis- and trans-decalin and cyclohexane (electron-hole migration) takes place. The existence of two conformations of the parent positive ion of cyclohexane, of which one does not transfer charge, is suggested.

Vibrational spectra and structure of halogen‐substituted cyclopropanes. III—cis‐ and trans‐1, 2‐diiodocyclopropane

AbstractThe infrared spectra of liquid cis‐ and trans‐1, 2‐diiodocyclopropane were measured from 4000 to 200 cm−1. Raman spectra between 4000 and 50 cm−1 of the two compounds as liquids and of the solid cis isomer were also obtained. All of the 21 normal vibrations of the two molecules were convincingly assigned on the basis of Raman depolarization ratios and group frequency correlations. Comparisons are made with the normal modes of related compounds. There is excellent agreement with those assignments previously proposed for the two isomers of 1, 2‐dibromocyclopropane, cis‐1, 2‐dichlorocyclopropane and related modes of iodocyclopropane.

Molecular Relaxation Study by Ultrasonic Spectroscopy

The ultrasonic velocity and absorption were measured over the frequency range from 3 MHz to 5 GHz at 20° and 30°C in liquid cis and trans-dichloroethylene. Two relaxation regions were found in the velocity-dispersion spectrum of trans-dichloroethylene, one centered at 450 MHz and the other around 20 GHz, and were analyzed in terms of vibrational-translational relaxation effect. All the fundamental vibrational modes of this molecule are categorized into two groups with different relaxation times of ∼10 ps and 430 ps. The relaxation was found also in cis-dichloroethylene.

Formation of fluorescent excited states of liquid cis- and trans-decalin by high energy radiation

The formation of fluorescent excited states of liquid cis- and trans-decalin by high-energy radiation has been investigated. The fluorescence resulting from pulsed irradiation in the presence and absence of solutes as well as the reaction of the solutes with the geminately recombining charged species is studied. The efficiency of formation of the fluorescent excited states as a result of recombination of excess electrons and electron holes in cis-decalin is 0.85. The delayed formation of fluorescent excited states as a result of charge recombination after a 30 ps pulse is observed and compared with calculations.

Raman spectral studies of cis‐2‐butene‐benzene mixtures

AbstractRaman spectra of neat liquid cis−2‐butene and cis−2‐butene‐benzene mixtures, covering the accessible composition range at 20°C and atomospheric pressure, have been obtained. Parameters of the benzene bands at 605.6, 1178 and 991.6 cm−1 and cis−2‐butene bands at 395.5, 871.5 and 1660 cm−1 are reported. Changes in the parameters as a function of concentration are interpreted in terms of a weak dipole‐induced dipole interaction and the consequent effect on rotational motions and resonance energy transfer.

VIBRATION SPECTRA OF CIS AND TRANS DICHLOROETHYLENE-d1

The infrared spectra of the vapor and the liquid, and the Raman spectra of liquid cis and trans C2HDCl2 have been obtained in the region 400–3300 cm−1 The observed spectra are in accordance with the assignment of Bernstein and Ramsay for cis and trans C2H2Cl2 and C2D2Cl2.

Raman Spectra of Cis- and Trans-2-Butene in the Gaseous and Liquid States*

The Raman spectra of gaseous and liquid cis- and trans-2-butene have been obtained with a three-prism glass spectrograph of linear dispersion 15A/mm at 4358A, together with polarization data for these compounds in the liquid state. For each compound six or seven fundamentals have been added to previous assignments, and one change has been made in the latter. The observed spectra have been interpreted in detail.

Vibration Spectra of Cis and Trans C2H2Cl2 and C2D2Cl2

The infra-red spectra of gaseous and liquid cis and trans C2H2Cl2 and C2D2Cl2 have been obtained in the region 3500 to 400 cm−1. The fine structure of a ⊥ band in trans C2H2Cl2 was also resolved and the least moment of inertia obtained. An assignment of all the fundamentals for the four molecules has been made. Calculations of potential functions and of the equilibrium constants for the reaction cis⇌trans support the assignment.

The Dielectric Properties of Solid and Liquid cis- and trans-Decahydronaphthalene

The Dielectric Properties of Solid and Liquid cis- and trans-Decahydronaphthalene