Structure Of Imide Research Articles

Synthesis, electro‐optic properties, and performance of novel fluorinated polyurethaneimide

AbstractUrethane imide anhydride oligomers with terminal groups as anhydride groups were designed and synthesized using second‐order nonlinear optical chromophore molecule, bisphenol AF‐type diethylidene dianhydride, and toluene diisocyanate as monomers. Polyurethaneimide (PUI) second‐order nonlinear optical polymers with the structure of imide and amino ester chain segments were then synthesized by the polycondensation reaction between urethane imide anhydride oligomers and aromatic diamine monomers. The glass transition temperature (Tg) of PUI reached 186°C, and the 5% heat‐loss decomposition temperature was 320°C. The corona‐polarized PUI had an electro‐optic (EO) coefficient (γ33) of 82 pm/V tested by the reflection method. The loss of light transmission of the polymer waveguide prepared with PUI as electro‐optical material was 1.13 dB/cm at 1550 nm. Mach–Zehnder type polymer waveguide electro‐optical modulators have been prepared based on the properties of the electro‐optic material PUI. The fabricated polymer EO modulators had favorable electro‐optic modulation response performance for low‐frequency electrical signals. The good modulation characteristics of the manufactured electro‐optical modulators proved that the synthesized PUI was a waveguide polymer material with good comprehensive performance.Highlights Electro‐optic fluorinated polyurethaneimide was synthesized. Polyurethaneimide as core material, polymer waveguide EO modulators were fabricated. The prepared modulators had good electro‐optic modulation performance.

Synthesis of new imides and imidoamides of citraconopimaric acid

For the first time, a method has been developed for the synthesis of aromatic imides of citraconopimaric acid by the interaction of primary aromatic amines (aniline, p-toluidine) and citraconopimaric acid in p-xylene at reflux. New aliphatic imides have been synthesized by the reaction of citraconopimaric acid and primary aliphatic amines (octyl-, octadecylamine) in a melt at 125–150°C. For the first time, the synthesis of citraconopimaric acid imidoamides was developed by treating citraconopimaric acid N-octylimide with thionyl chloride and subsequent reaction of the resulting acid chloride with primary aromatic amines (aniline, p-bromoaniline). A method has been developed for the synthesis of aliphatic imides of the rosin-citraconic adduct (in the form of technical products) by its interaction with primary aliphatic amines (octyl- and octadecylamine) at 180–200°C for 8–12 hours.Together with Belarusian state technological university, the relationship between the structure of imides of rosin-citraconic adducts as modifiers of unfilled and filled industrial rubber compounds was studied, and the obtained additives were found to improve the technological properties of compositions while maintaining, and in some cases improving physical and mechanical parameters (increasing the resistance of compositions to thermal aging, bond strength of the cord with rubber, etc.).

Structure, morphology and energy storage properties of imide conjugated microporous polymers with different cores and the corresponding composites with CNT

Conjugated microporous polymers (CMPs) have attracted more and more attention owing to inherent pore and high specific area. However, the low conductivity for CMPs limits its application in energy storage. Herein, three kinds of imide conjugated microporous polymers (pNTCDA-TAPB, pNTCDA-TAPM and pNTCDA-TPAT) with different cores were achieved via the condensation reaction. Also, the corresponding composites (pNTCDA-TAPB@CNT, pNTCDA-TAPM@CNT and pNTCDA-TPAT@CNT) were prepared by the in-situ composition with CNT. Among the three polymers, pNTCDA-TPAT exhibits the highest specific capacity of 217.4 F g−1 at 0.5 A g−1 in the neutral electrolyte than that of others, which is a high value among the reported CMPs-based energy storage materials. FT-IR spectra at the applied voltages proved that the excellent energy storage capacity for pNTCDA-TPAT could be attributed to the involvement of the triazine central core except of imide units participating in the reduction of energy storage. However, the energy storage capacity of pNTCDA-TAPB after compositing with CNT has been greatly improved compared with the pure polymer while the energy storage capacity improvement for others two polymers with CNT (pNTCDA-TAPM@CNT and pNTCDA-TPAT@CNT) is not significant. SEM and HR-TEM results indicate that the distinct difference for the three polymers after composition with CNT could be attributed to the formation of unique core-shell structure for pNTCDA-TAPB@CNT system, which may be beneficial to the ion migration and electron transport.

A New N-Substituted 1H-Isoindole-1,3(2H)-Dione Derivative-Synthesis, Structure and Affinity for Cyclooxygenase Based on In Vitro Studies and Molecular Docking.

Isoindoline-1,3-dione derivatives constitute an important group of medicinal substances. In this study, nine new 1H-isoindole-1,3(2H)-dione derivatives and five potential pharmacophores were obtained in good yield (47.24–92.91%). The structure of the new imides was confirmed by the methods of elemental and spectral analysis: FT–IR, H NMR, and MS. Based on the obtained results of ESI–MS the probable path of the molecules decay and the hypothetical structure of the resulting pseudo-molecular ions have been proposed. The physicochemical properties of the new phthalimides were determined on the basis of Lipiński’s rule. The biological properties were determined in terms of their cyclooxygenase (COX) inhibitory activity. Three compounds showed greater inhibition of COX-2, three compounds inhibited COX-1 more strongly than the reference compound meloxicam. From the obtained results, the affinity ratio COX-2/COX-1 was calculated. Two compounds had a value greater than that of meloxicam. All tested compounds showed oxidative or nitrosan stress (ROS and RNS) scavenging activity. The degree of chromatin relaxation outside the cell nucleus was lower than the control after incubation with all test compounds. The newly synthesized phthalimide derivatives showed no cytotoxic activity in the concentration range studied (10–90 µM). A molecular docking study was used to determined interactions inside the active site of cyclooxygenases.

Unexpected reversal of stereochemistry observed in the addition of methallyltrimethylsilane to a chiral α-keto imide.

A Lewis acid-promoted nucleophilic addition of methallyltrimethylsilane to a chiral α-keto imide proceeded with stereoselectivity opposite to that predicted from Soai's report. The difference in the structure of α-keto imides between Soai's and our cases might have affected the diastereofacial selectivity.

Long-Term Lubrication at 500 °C Using Continuously Replenishable Solid Lubricating Film Polymerized In Situ by Gasified Monomers PA and PPD

Through the introduction of gas-phase monomers phthalic anhydride (PA) and p-phenylenediamine (PPD), replenishment of lubricants during high-temperature friction processes could be realized. According to Fourier transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC-MS) analyses, in a 10-min ball–disc friction test at 500 °C, the introduced monomers contacted and polymerized in the gas phase to form solid products with the structure of imides or long carbon chains, which provided superior thermal stability. Solid lubricating films were generated on the disc surface by the physical deposition of these polymerized products and then fall off and attach to the contact position of the ball to form a transfer film. Compared to nonlubricated friction, the coefficient of friction (COF) was reduced from 0.54 to 0.24, and the wear rates of the balls and disc were reduced from 8.32 × 10−6 to 0.65 × 10−6 mm3·N−1·m−1 and from 2.62 × 10−4 to 7.48 × 10−6 mm3·N−1·m−1, respectively. With continued friction but no further introduction of monomers, the solid lubricating film generated in the initial 10 min could provide even more remarkable lubrication for at least the next 15 min, with a minimum COF of 0.01. This could be related to the reinforcing and synergistic lubricating effect of carbonized product powders that gradually formed a continuous phase on the polymerized products’ matrix. After the COF increased, low friction could be re-attained by reintroduction monomers, but lubrication would be limited by the previous wear. This novel lubricating film shows potential in high-temperature lubrication, because it has both the effectiveness and stability of solid lubrication and the replenishability of gas lubrication.

Bioresearch of New 1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones.

The subject of the work was the synthesis of new derivatives of1H-pyrrolo[3,4-c]pyridine-1,3(2H)-dione with potential analgesic and sedative activity. Eight compounds werereceived. The analgesic activity of the new compounds was confirmed in the “hot plate” test and in the “writhing” test. All tested imides 8–15 were more active in the “writhing” test than aspirin, and two of them, 9 and 11, were similar to morphine. In addition, all of the new imides inhibited the locomotor activity in mice to a statistically significant extent, and two of them also prolonged the duration of thiopental sleep.On the basis of the results obtained for the previously synthesized imides and the results presented in this paper, an attempt was madeto determine the relationship between thechemical structure of imides and their analgesic and sedativeproperties.

FIRST-PRINCIPLE SIMULATION OF LITHIUM IMIDE CRYSTAL STRUCTURE IN THE LOW-TEMPERATURE PHASE

Low-symmetry structure of lithium imide, space group Ci, is established using the density functional method in the all-electron approach of the LCAO approximation. The obtained unit cell parameters are close to those of the low-temperature phase, space group $$Fd\bar{3}m$$ ; hydrogen atoms are uniformly distributed in the crystal lattice. The band structure and electron density maps are calculated, the nature of chemical bonding is analyzed.

Synthesis and electronic structure studies of a Cr-imido redox series.

The effect of metal identity, d-electron count, and coordination geometry on the electronic structure of a metal-ligand multiple bond (MLMB) is an area of active exploration. Although high oxidation state Cr imidos have been extensively studied, very few reports on low-valent Cr imidos or the interconversion of redox isomers exist. Herein, we report the synthesis and characterization of a family of dipyrrinato Cr imido complexes in oxidation states ranging from CrIII to CrV, showcasing the influence of the weak-field dipyrromethene scaffold on the electronic structure and coordination geometries of these Cr imides.

Synthesis and properties of cycloaliphatic epoxy resins containing imide and diphenyl sulfone

A novel variety of cycloaliphatic epoxy resins containing imide and diphenyl sulfone (named as 4,4′-bis[4-(4,5-epoxy-1,2,3,6-tetrahydro-phthalimido) phenoxy] diphenyl sulfone, BIES) is designed and synthesized through the three-step procedure. The mixtures of BIES and diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylate (TDE-85) are cured with methyl tetrahydrophthalic anhydride. Fourier transform infrared spectrum and proton nuclear magnetic resonance spectrum confirm that the BIES contains the chemical structure of imide and diphenyl sulfone. The measurements of glass transition temperature ( Tg), heat distortion temperature (HDT), and the 5% weight loss temperature ( T5%) show that the co-cured BIES/TDE-85 exhibits excellent heat resistance. For the BIES/TDE-85 with mass ratio of 0.2, Tg, HDT, and T5% of the co-cured epoxy are 175°C, 162°C, and 290°C, respectively. The impact strength increases from 117 J m−1 to 139 J m−1 with the increasing of the mass ratios of the BIES/TDE-85 from 0 to 0.2.

Isomer effect on the near-infrared electrochromism of anthraquinone imides

To deeply explore the interplay between molecular structure and near-infrared electrochromism of anthraquinone imides, two pairs of unsubstituted isomers (Ia and Ib) and nitro-substituted isomers (IIa and IIb) of anthraquinone imides were synthesized, in which the molecules Ia and IIa took more linear shapes than Ib and IIb. Cyclic voltammetry and spectroelectrochemistry were combined to investigate their electrochemical properties. Cyclic voltammetry showed that Ib and IIb revealed decreased first reduction potentials and low cyclic stability compared to their isomers, indicating that the isomerization weakened the stabilization effect. Upon one-electron reduction, both the absorption wavelengths and absorption intensities of radical anions were greatly dependent on the structures of isomers. The radical anions of Ia, IIa, and IIb illustrated NIR absorptions peaked at 820, 1260, and 1380nm, respectively, but that of Ib exhibited only weak absorption in the visible region centered at 660nm. Gaussian calculations suggested that the electrons were delocalized over the whole molecular skeletons of Ia and IIa radical anions, but the effective conjugation length was interrupted on the imide section in both Ib and IIb. The isomer effects on the effective conjugation length and electron density distribution were considered to rationalize the different electrochromic behaviors.

Structural Stability, Electronic Structure and Mechanical Properties of Li–N–H System

Ab initio calculations are performed to investigate the ground state properties, structural phase transition, electronic structure and mechanical properties of lithium nitride (Li3N), lithium imide (Li2NH) and lithium amide (LiNH2). The computed ground state properties like equilibrium lattice constant, cell volume, valence electron density, cohesive energy, bulk modulus and its derivatives are in good agreement with available experimental data. The structural phase transitions from α-P6/mmm to β-P63/mmc phase at a pressure of 17.5 GPa in Li3N and cubic (Fm3m) to hexagonal (P63/mmc) phase at a pressure of 102 GPa in lithium imide (Li2NH) are observed. A new high pressure hexagonal (P63/mmc) phase is predicted for Li2NH. Electronic structure reveals that Li3N and LiNH2 are semiconductors, whereas Li2NH is an insulator. The calculated elastic constants indicate that these materials are mechanically stable at ambient condition.

Unusual reaction of diazomethane with stereoisomeric 3-(benzylcarbamoyl)-5,6,7,8-tetrachloro-1,4-methano-1,2,3,4-tetrahydronaphthalene-2-carboxylic acids

Diazomethane is commonly used as efficient alkylating agent in the preparation of methyl esters and as a component in [2 + 3]-cycloaddition reactions [1]. However, there are no published data on dehydrating ability of diazomethane. With a view to accomplish cis–trans epimerization of cyclic amido acids I and II, an attempt was made to convert them into endo-cis and exo-cis amido esters III and IV by treatment with diazomethane in diethyl ether at 20°C. Unexpectedly, these reactions chemoselectively afforded the corresponding dicarboxylic acid imides V and VI, while even traces of esters III and IV were not detected. The structure of imides V and VI was confirmed by the H and C NMR spectra and independent synthesis from the corresponding anhydrides. It should be noted that known methods for the preparation of imides from amido acids require more severe conditions, in particular prolonged heating in high-boiling solvents (usually in DMF or Ac2O) in the presence of dehydrating agents [2]. rel-(1S,2R,3S,4R)-N-Benzyl-5,6,7,8-tetrachloro1,4-methano-1,2,3,4-tetrahydronaphthalen-2,3-dicarboximide (V). A solution of diazomethane in diethyl ether was added to a suspension of 0.9 g of amido acid I in diethyl ether until the mixture became homogeneous. The mixture was evaporated at 20oC, ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 10, pp. 1548–1549. © Pleiades Publishing, Ltd., 2013. Original Russian Text © S.A. Ismailov, 2013, published in Zhurnal Organicheskoi Khimii, 2013, Vol. 49, No. 10, pp. 1569–1570.

Perylene Imides for Organic Photovoltaics: Yesterday, Today, and Tomorrow

Perylene imides have been an object of research for 100 years and their derivatives are key n-type semiconductors in the field of organic electronics. While perylene diimides have been applied in many electronic and photonic devices, their use can be traced back to the first efficient organic solar cell. By functionalizing different positions of the in total 12 positions (four peri, four bay, and four ortho-positions) on the perylene core, perylene imides with significantly different optical, electronic and morphological properties may be prepared. Perylene imides and their derivatives have been used in several types of organic photovoltaics, including flat-, and bulk-heterojunction devices as well as dye-sensitized solar cells. Additionally perylene imides-based copolymers or oligomers play an important role in single junction devices. In this review, the relationship between the photovoltaic performance and the structure of perylene imides is discussed.

Magnesium Imide: Synthesis and Structure Determination of an Unconventional Alkaline Earth Imide from Decomposition of Magnesium Amide

Magnesium imide (MgNH) was produced by monitoring the decomposition process of magnesium amide with in situ neutron diffraction. Significant changes in the structure of magnesium amide are detected during heat treatment and eventually result in the formation of crystalline MgNH. A model for the crystal structure of magnesium imide (MgNH) is presented for the first time. Remarkably, magnesium imide offers unique structural features similar to the cyclosilicate class and can be described as a porous solid formed by a sequence of linked chains of face sharing Mg(6)N(6) hexagonal prism clusters.

The structural properties of amides and imides as hydrogen storage materials

AbstractWe discuss crystal structure of amides and imides, which are focusing on promising hydrogen storage materials. They are ionic crystal with anion of (NH2)–or (NH)2–and cation of Li+, Na+, Mg2+, Ca2+, and so forth. We also discuss reaction mechanisms on hydrogen ab/desorption of amide/imide hydrogen storage materials.

Effect of structure of aromatic imide–amines on curing behavior and thermal stability of diglycidyl ether of bisphenol‐A

AbstractThe curing behavior of diglycidyl ether of bisphenol‐A (DGEBA) with aromatic imide–amines having aryl ether, sulfone, and methylene linkages was studied using differential scanning calorimetry (DSC). Six imide–amines of varying structure were synthesized by reacting 1 mol of naphthalene 1,4,5,8‐tetracarboxylic dianhydride (N) or 4,4′‐oxodiphthalic anhydride (O) with excess (>2 mol) of 4,4′‐diaminodiphenylether [E] or 4,4′‐diaminodiphenyl methane [M] or 4,4′‐diaminodiphenyl sulfone [S]. The imide–amines prepared by reacting O or N with S, M, and E have been designated as OS/NS; OM/NM, and OE/NE, respectively. Structural characterization of imide–amines was done using FTIR, 1H NMR, 13C NMR, and elemental analysis. The curing behavior of DGEBA in the presence of stoichiometric amount of imide–amines was investigated by recording DSC scans. A broad exothermic transition was observed and the peak exotherm temperature was found to be dependent on the structure of imide–amines. The peak exotherm temperature (Tp) was lowest in case of imide–amines OE and highest in case of imide–amines NS/OS. Thermal stability of isothermally cured DGEBA in the presence of imide–amines was evaluated by dynamic thermogravimetry. The char yield was highest for resin cured with imide–amines NE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

First-principles study of cation and hydrogen arrangements in the Li-Mg-N-H hydrogen storage system

Recently it was discovered that a total of $5.6\phantom{\rule{0.3em}{0ex}}\mathrm{wt.}\phantom{\rule{0.2em}{0ex}}%$ ${\mathrm{H}}_{2}$ could be released from the 1:2 mixture of lithium amide and magnesium hydride at temperatures as low as $150\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$. With a reaction enthalpy of $44\phantom{\rule{0.3em}{0ex}}\mathrm{KJ}∕\mathrm{mol}$ ${\mathrm{H}}_{2}$, this system has high potential for on-board hydrogen storage applications. The fully desorbed product is believed to be a mixed lithium and magnesium imide ${\mathrm{Li}}_{2}\mathrm{Mg}{(\mathrm{N}\mathrm{H})}_{2}$. In this work, the crystal structure of this mixed imide is studied from total-energy density-functional calculations. Based on a recent experimentally established space group, possible ordered configurations are examined. Important local orderings are identified for the experimentally observed disordered phase at room temperature. These unique local arrangements are also connected with the observed structural transitions above room temperature. In addition, the local ordering in $\mathrm{Mg}{(\mathrm{N}{\mathrm{H}}_{2})}_{2}$ is analyzed. The similarity and difference of local arrangements among hydrogen, cations, and vacancies are discussed for the three amide (imide) systems: $\mathrm{Li}\mathrm{N}{\mathrm{H}}_{2}$, $\mathrm{Mg}{(\mathrm{N}{\mathrm{H}}_{2})}_{2}$, and ${\mathrm{Li}}_{2}\mathrm{Mg}{(\mathrm{N}\mathrm{H})}_{2}$. The identification of the cation and hydrogen local orderings are expected to facilitate the design of new mixed imides and amides as hydrogen storage materials with desired physical properties.

Synthesis of endo,exo-1,2,3,4,11,11-hexachlorotricyclo[6.2.1.05,10]-undec-2-en-7,8-dicarboxylic acid N-(2,4,6-tribromophenyl)imide

Apreparation method was developed for endo,exo-1,2,3,4,11,11-hexachlorotricyclo-[6.2.1.05,10]undec-2-ene-7,8-dicarboxylic acid N-tribromophenylimide by acylation of 2,4,6-tribromoaniline with this acid anhydride. The structure of imide obtained was proved by IR spectrum, TLC method, and by independent synthesis.

The molecular structure of N-fluorobis(trifluoromethanesulfonyl)imide, NF(SO2CF3)2, as studied in the gas phase by electron diffraction restrained by ab initio calculations

The structure of N-fluorobis(trifluoromethylsulfonyl)imide, prepared by a relatively safe and easy method, has been determined by gas-phase electron diffraction (GED), employing the SARACEN method, with flexible restraints based on the MP2/6-311G* structure, and by X-ray crystallography at 150 K. The strongly electron-withdrawing CF(3) and SO(2)CF(3) groups make the C-S and N-S distances long, averaging 187.7(3) and 171.7(3) pm, respectively, in the gas phase. The gas consists of two conformers, one (75%) with a CF(3) group on each side of the SNS plane, one anti-periplanar and one syn-periplanar to the further N-S bond (ap, sp), and the other with both CF(3) groups on the same side, i.e. denoted ap, ap. These conformers have very different SNS angles, 126.9(9) degrees and 117.1(17) degrees respectively. In the crystal all molecules have the ap, sp conformation, with parameters similar to those found for this conformer in the gas phase.