Phthalimide Moieties Research Articles

Volatile Electrical Switching and Static Random Access Memory Effect in a Functional Polyimide Containing Oxadiazole Moieties

A solution-processable functional polyimide, P(BPPO)-PI, containing oxadiazole moieties (electron donors) and phthalimide moieties (electron acceptors) was synthesized. A switching device, based on a solution-cast thin film of P(BPPO)-PI sandwiched between an indium−tin oxide (ITO) bottom electrode and an Al top electrode, exhibits two accessible conductivity states and can be switched from the low-conductivity (OFF) state to the high-conductivity (ON) state when swept positively or negatively, with an ON/OFF current ratio on the order of 1 × 104. The device exhibits ON state “remanence”, with the ON state retainable for a period of about 4 min after turning off the power. The ON state can be electrically sustained either by a refreshing voltage pulse of −1 V or by a continuous bias of −1 V. The “remanent” but volatile nature of the ON state and the ability to write, read, and sustain the electrical states with bias are characteristic features observed in a static random access memory (SRAM). The mechanis...

Synthesis, photophysics, electrochemical and electroluminescent properties of divinylene compounds with phthalimide moieties

Three new divinylene compounds F, C and P which contained fluorene, carbazole and phenylene as central unit, respectively, and terminal phthalimide groups were synthesized by Heck coupling. The alkyl or alkoxy chains attached to the central unit as well as the cyclohexyl ring attached to the terminal phthalimides render the samples very soluble in common organic solvents. They had relatively low glass transition temperatures ( T g's), being in the range of 54–81 °C. P was stable up to about 200 °C while F and C were stable up to 300 °C. The absorption maximum was located at 387–440 nm with optical band gap of 2.48–2.56 eV. They emitted blue-green light with emission maximum at 484–562 nm. P showed the most red-shifted absorption and emission maximum. The HOMO and LUMO levels of the compounds, estimated from their cyclic voltammograms, were −6.42 to −5.58 eV and −3.06 to −2.99 eV, respectively, from which their band gaps were estimated to be 3.36 eV, 2.68 eV, and 2.52 eV. The emission spectra and performance of the EL devices, using blends of the compounds and PVK as emitting layer, also depended strongly on the compounds. The P device emitted green light (530 nm) with maximal luminance and current efficiency being at 1358 cd/m 2 and 0.57 cd/A, while those of the F device were green-blue (490 nm), 593 cd/m 2 and 0.22 cd/A.

Volatile electrical switching in a functional polyimide containing electron-donor and -acceptor moieties

A solution-processable functional polyimide (PYTPA-PI), containing triphenylamine-substituted diphenylpyridine moieties (PYTPA, electron donors) and phthalimide moieties (PI, electron acceptors), was synthesized. The copolymer exhibits a high glass transition temperature of 342 °C. A switching device, based on a solution-cast thin film of PYTPA-PI sandwiched between an indium-tin oxide (ITO) bottom electrode and an Al top electrode, exhibits two accessible conductivity states and can be switched from the low-conductivity (OFF) state to the high-conductivity (ON) state, with an ON/OFF current ratio of more than 103, at the threshold voltage of about 2.7 V. The ON state is volatile and relaxes readily to the OFF state. However, it can be electrically sustained by a refreshing voltage pulse of 2 V. The ON state can also be reset to the initial OFF state by a reverse bias of −0.9 V. The ability to write, erase, read, and refresh the electrical states fulfills the functionality of a dynamic random access memory. The electronic transitions and transport mechanisms associated with the memory effect were elucidated from molecular simulation. In comparison with that of other functional polyimides, the electrical switching performance in PYTPA-PI illustrates the possibility of tuning memory properties in imide polymers via molecular design and synthesis.

One-pot polyamidation reaction of optically active aromatic diacid containing methionine and phthalimide moieties with aromatic diamines under microwave irradiation and traditional heating

An optically active diacid containing phthalimide and l-methionine moiety was prepared in three steps, and was polymerized with several aromatic diamines to obtain a new series of optically active polyamides (PAs) through direct polyamidation using triphenyl phosphite/pyridine/ N-methyl-2-pyrrolidone/CaCl 2 system as condensing agent. The polymerization reactions were carried out under both conventional heating and microwave-assisted irradiation. The data obtained by these methods indicate that, high yields and similar inherent viscosities are resulted. It is worth to mention that in the case of microwave conditions, a drastic decrease in reaction time (3 min vs. 5 h) and cleaner reaction have been achieved. These polymers are readily soluble in polar organic solvents such as N, N-dimethyacetamide, N, N-dimethyformamide, dimethyl sulfoxide. The obtained polymers were characterized by FT-IR, specific rotation measurements, elemental analysis and 1H NMR techniques. The thermal stability of the resulting PAs were evaluated with thermogravimetric analysis and differential scanning calorimetry techniques under a nitrogen atmosphere which indicate they are moderately stable.

Room Temperature Ionic Liquids as Replacements for Organic Solvents: Direct Preparation of Wholly Aromatic Polyamides Containing Phthalimide and S-valine Moieties

Ionic liquids (IL)s are often considered as green solvents capable of replacing traditional organic solvents and have extensively studied in material chemistry and catalysis. In this work a new class of wholly aromatic and optically active polyamides (PAs) having phthalimide and S-valine pendent groups were prepared by the reaction of 5-(2-phthalimidyl-3-methylbutanoylamino)isophthalic acid as a diacid monomer with various aromatic diamines. ILs media in the presence of triphenyl phosphite was used as a condensing agent. The resulting novel optically active PAs with inherent viscosities ranging from 0.35–0.71 dLg−1, were obtained in excellent yields. This method of polymerization was also compared with direct polyamidation using conventional phosphorylation reaction. Introduction of bulky and flexible clusters in these polymers pendent group, make them readily soluble in most organic solvents. The resulting polymers show optical rotation, therefore, are optically active.

Crystal structure of 3,5-bis(phtalimidomethyl)benzene-tert-butyldimethylsilyl ether, C30H30N2O5Si

Article Crystal structure of 3,5-bis(phtalimidomethyl)benzene-tert-butyldimethylsilyl ether, C30H30N2O5Si was published on June 1, 2007 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 222, issue 2).

A novel potent non-nucleoside reverse transcriptase inhibitor acylthiocarbamate derivative with extensive intramolecular π–π interactions

In the crystal structure of the novel acylthiocarbamate derivative O-[2-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)ethyl] N-(4-methylphenyl)-N-(3-nitrobenzoyl)thiocarbamate, C25H19N3O6S, intra- and intermolecular pi-pi interactions occur between the phthalimide and N-benzoyl moieties. The partial atomic charges, calculated by ab initio methods, are consistent with the observed structure.

Synthesis and structure of unusually stable linear copper(I) complexes with blue fluorescence

A new fluorescent ligand 2-(4′-aminophthalimidoethyl)pyridine ( L 2 ) has been synthesized. Solid state structures of L 2 and 2-(4′-aminophthalimidomethyl)pyridine ( L 1 ) have been determined by X-ray crystallography. While L 1 crystallizes in the non-centrosymmetric orthorhombic space group Fdd2, L 2 crystallizes in the monoclinic space group C2/c. The molecular packing in both systems is dominated by intermolecular N–H⋯O and N–H⋯N hydrogen bonds and relative bending of the planes defined by the pyridine and phthalimide moieties. An unusually stable two-coordinate complex of copper(I) with L 2 , Cu(L 2 ) 2 , has been synthesized upon in situ reduction of copper(II) at room temperature. This complex, which has been characterized by X-ray crystallography, crystallizes in the centrosymmetric space group C2/c with a linear N–Cu–N geometry. The Cu–N bond distance (1.89 Å) in Cu(L 2 ) 2 is found to be similar to that in Cu(L 1 ) 2 . Both the complexes display interesting structural feature, arising from weak Cu⋯O interactions (3.12 Å in Cu(L 1 ) 2 and 2.71 Å in Cu(L 2 ) 2 ) between the copper and oxygen atoms of the ClO 4 - counteranion, leading to a linear network with alternate ClO 4 - and Cu + ions. A 2-D network determined by intermolecular N–H⋯O hydrogen bonding is also observed. These complexes are found to be highly resistant toward oxidation both in the solid state and in solution. The new complex Cu(L 2 ) 2 , in which the metal center is more separated from the 4-aminophthalimide moieties, exhibits lesser stability than Cu(L 1 ) 2 . Close contact between copper and one of the imide oxygen atoms of the ligand framework was detected as 3.03 Å in Cu(L 1 ) 2 and 4.0 Å in Cu(L 2 ) 2 , indicating a relatively weaker electronic interaction in the later complex. Thus, the exceptional stability of these complexes is attributed to the electronic environment provided by the 4-aminophthalimide and perchlorate moieties on the metal center.

Synthesis and anticonvulsant evaluation of N-substituted-isoindolinedione derivatives.

A series of N-substituted-1,3-isoindolinedione derivatives (2-16) were synthesized for the purpose of defining the effect of N-substitution on the anticonvulsant activity of these derivatives. The target compounds (2-16) were obtained by condensation of phthalic anhydride with the corresponding amine derivative. The structures of the synthesized derivatives (2-16) were confirmed by means of IR, 1H-NMR, 13C-NMR, MS and elemental analyses. The anticonvulsant activity of all compounds (2-16) were evaluated by subcutaneous pentylenetetrazole seizure threshold test at doses of 0.2, 0.4 and 0.8 mmol/kg compared with sodium valproate as a positive control. Their neurotoxicity were determined by the rotorod test. Many of the present series of compounds showed good anticonvulsant activity at the tested doses, as compared to sodium valproate. Three of them (4, 6 and 11) exhibited 100% protection against convulsions, neurotoxicity and death at all tested doses. Out of the series, two compounds (12 and 13) were completely inactive with 100% mortality. 3-(p-chlorophenyl)-4-(1,3-dioxo-2,3-dihydro-1H-2-isoindolyl)butanoic acid derivative (11) has emerged as the most active compound which is 20 times more active than valproate with ED50 8.7, 169 mg/kg; TD50 413, 406 mg/kg and PI 47.5, 2.4. The results revealed the importance of the combination of baclofenic and phthalimide moieties (compound 11) as a promising anticonvulsant candidate.

Synthesis and characterization of novel polyimides with 2,2‐bis[4(4‐aminophenoxy)phenyl]phthalein‐3′,5′‐bis(trifluoromethyl)anilide

Abstract2,2‐Bis[4(4‐aminophenoxy)phenyl]phthalein‐3′,5′‐bis(trifluoromethyl)anilide (6FADAP), containing fluorine and phthalimide moieties, was synthesized via the Williamson ether condensation reaction from 1‐chloro‐4‐nitrobenzene and phenolphthalein‐3′,5′‐bis(trifluoromethyl)anilide, which was followed by hydrogenation. Monomers such as 2,2‐bis[4(4‐aminophenoxy)phenyl]phthalein‐anilide containing phthalimide groups and 2,2‐bis[4(4‐aminophenoxy)phenyl]phthalein containing only phthalein moieties were also synthesized for comparison. The monomers were first characterized by Fourier transform infrared (FTIR), 1H NMR, 19F NMR, elemental analysis, and titration and were then used to prepare polyimides with 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride. The polyimides were designed to have molecular weights of 20,000 g/mol via off‐stoichiometry and were characterized by FTIR, NMR, gel permeation chromatography (GPC), differential scanning calorimetry, and thermogravimetric analysis. Their solubility, water absorption, dielectric constant, and refractive index were also evaluated. The polyimides prepared with 6FADAP, containing fluorine and phthalimide moieties, had excellent solubility in N‐methylpyrrolidinone, N,N‐dimethylacetamide, tetrahydrofuran, CHCl3, tetrachloroethane, and acetone, and GPC analysis showed a molecular weight of 18,700 g/mol. The polyimides also exhibited a high glass‐transition temperature (290 °C), good thermal stability (∼500 °C in air), low water absorption (1.9 wt %), a low dielectric constant (2.81), a low refractive index, and low birefringence (0.0041). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3361–3374, 2003

Unusual molecular conformation in dissymmetric propylene-linker compounds containing pyrazolo[3,4-d]pyrimidine and phthalimide moieties.

The crystal structure of 4,6-bis(methylsulfanyl)-1-phthalimidopropyl-1H-pyrazolo[3,4-d]pyrimidine, C(18)H(17)N(5)O(2)S(2), (VI), reveals an unusual folded conformation due to an apparent intramolecular C-H.pi interaction between the 6-methylsulfanyl and phenyl groups. However, the closely related compound 6-methylsulfanyl-1-phthalimidopropyl-4-(pyrrolidin-1-yl)-1H-pyrazolo[3,4-d]pyrimidine, C(21)H(22)N(6)O(2)S, (VII), exhibits a fully extended structure, devoid of any intramolecular C-H.pi or pi-pi interactions. The crystal packing of both molecules involves intermolecular stacking interactions due to aromatic pi-pi interactions. In addition, (VI) exhibits intermolecular C-H.O hydrogen bonding and (VII) exhibits dimerization of the molecules through intermolecular C-H.N hydrogen bonding.

Poly(arylene ether)s Containing 1,2,4-Triazole and Phthalimide or Naphthalimide Moieties Joined by a N−N Linkage

The synthesis and characterization of new monomers and polymers containing the 1,2,4-triazole group are described. A model reaction of 4-N-amino-3,5-diphenyltriazole with phthalic and naphthalic anhydride demonstrated the preparation of the 1,2,4-triazole-imide compounds containing a N−N linkage. From 4-amino-3,5-bis(4-hydroxyphenyl)triazole four new bisphenols with pendent phthalimide or naphthalimide moieties linked through a N−N linkage were prepared in a one-step reaction in high yield. Poly(aryl ether)s were synthesized from these bisphenols, or their carbamate derivatives, by reaction with various activated arylene difluorides. The reactions were carried out in DMSO in the presence of potassium carbonate to yield high molecular weight, amorphous, and thermally stable polymers with pendent imide moieties joined by a N−N linkage. A new bisphenol with a pendent 3,5-diphenyl-1,2,4-triazole was prepared by an imidization reaction of an anhydride bisphenol with 4-amino-3,5-diphenyltriazole. Polymerization with activated difluoro compounds gave poly(aryl ether)s with a pendent 1,2,4-triazole moiety. These polymers had high Tg's, from 222 to 283 °C. Copolymers containing the 1,2,4-triazole in the polymer backbone as well as pendent were also prepared. Using decafluorobiphenyl as coreactant, extremely high molecular weight polymers were obtained at lower polymerization temperature, 90−100 °C, in a shorter reaction time. The polymers formed clear, transparent, flexible, and tough films from DMF solution. Many of the polymers showed strong blue to greenish-yellow fluorescence from 428 to 510 nm in solution and in the solid state under UV, depending upon the monomer composition of the polymer.

Elevation of ligand binding to muscarinic M(2) acetylcholine receptors by bis(ammonio)alkane-type allosteric modulators.

Bis(ammonio)alkane-type compounds are archetypal muscarinic allosteric modulators. Phthalimido-substituted hexane-bis-ammonium agents were methylated in the phthalimide moieties and the lateral propyl side chains. All compounds retarded allosterically the dissociation of the orthosteric ligand [(3)H]N-methylscopolamine ([(3)H]NMS) from porcine heart M(2) receptors. [(3)H]NMS equilibrium binding was reduced, left unaltered, or elevated, depending on the degree and position of methylation. This is the first time that an allosteric elevation of ligand binding is demonstrated for bis(ammonio)alkane-type compounds.

Structure-activity relationships in a series of bisquaternary bisphthalimidine derivatives modulating the muscarinic M(2)-receptor allosterically.

Hexane-bisammonium-type compounds containing lateral phthalimide moieties are well-established ligands of the common allosteric binding site of muscarinic M(2) receptors. Previous structure-activity relationships (SAR) revealed two positively charged centers and two lateral phthalimide moieties in a defined arrangement to be essential of a high allosteric potency. The purpose of this study was to replace one carbonyl group of the phthalimides with hydrogens, hydroxy, alkoxy, phenyl, benzyl, and benzylidene groups in order to check the influence of these substituents on the allosteric activity in antagonist-linked receptors. The analysis of the quantitative SAR indicated that a high allosteric potency is related to a certain amount of rigidity as well as polarizibility and the ability to form hydrophobic interactions.

Ligands for the common allosteric site of acetylcholine M2-receptors: development and application

Ligands for the allosteric site of acetylcholine M2 receptors are able to retard the dissociation of simultaneously bound ligands for the orthosteric site. This effect promotes receptor occupation by the orthosteric ligand. The allosteric effect opens various therapeutic perspectives, e.g., in organophosphorus poisoning. The aim of our studies was to optimize the affinity of the modulators for the common allosteric binding site of muscarinic M2 receptors, the orthosteric site of which was liganded with the N-methylscolopamine. The phthalimido substituted hexane-bisammonium compound W84 served as a starting point. Previous molecular modelling studies revealed two positive charges and two aromatic imides in a sandwich-like arrangement to be essential for a high allosteric potency. A three-dimensional quantitative structure activity relationship (3D QSAR) analysis predicted compounds with substituents of increasing size on the lateral imide moieties to enhance the affinity for the allosteric binding site. Thus, we synthesized and pharmacologically evaluated compounds bearing “saturated” phthalimide moieties as well as phthalimidines with substituents of systematically increasing size in position 3 or on the aromatic ring at one or both ends of the molecule. Within each series, QSAR could be derived: 1. “Saturation” of the aromatic ring of the phthalimide moiety results in less potent compounds. 2. Increasing the size of the substituents in position 3 of the phthalimide enhances the potency. 3. Putting substituents on the aromatic part of the phthalimide increases the potency more effectively: the introduction of a methyl group in position 5 gave a compound with a potency in the nanomolar concentration range which was subsequently developed as the first radioligand for the allosteric binding site.

Probing the size of a hydrophobic binding pocket within the allosteric site of muscarinic acetylcholine M 2-receptors

Hexane-bisammonium-type compounds containing lateral phthalimide moieties are known to have a rather high affinity for the allosteric site of muscarinic M 2 receptors. In order to get more insight into the contribution of the lateral substituents for alloster binding affinity, a series of compounds with unilaterally varying imide substituents were synthesized and tested for their ability to retard allosterically the dissociation of [ 3H]N-methylscopolamine from the receptor protein (control t 1 2 = 2 min; 3 mM MgHCO 4, 50 mM Tris, pH 7.3, 37 °C). Among the test compounds, the naphthalimide containing agent (half maximum effect at EC 50,diss = 60 nM) revealed the highest potency. Apparently, its affinity for the allosteric site in NMS-occupied receptors is 20fold higher compared with the phthalimide containing parent compound W 84. Analysis of quantitative structure-activity relationships yielded a parabolic correlation between the volume of the lateral substituents and the allosteric potency. The maximal volume was determined to be approximately 600 Å 3 suggesting that the allosteric binding site contains a binding pocket of a defined size for the imide moiety.

Synthesis of phthalimide-based alkali-dischargeable azo disperse dyes and analysis of their alkali--Hydrolysis mechanism

Three alkali-dischargeable azo disperse dyes containing phthalimide moieties were synthesized. 4-Aminophthalimide which was used as a diazo component was prepared from phthalimide and coupled with three coupling components. Some physico-chemical properties of the synthesized dyes were also measured. The alkali dischargeable properties of the synthesized dyes were verified through analysis of the dye hydrolysis under alkali discharge conditions by IR, mass and UV--Visible spectrophotometry. These phthalimide based dyes could thus obviate the need for the use of hydrosulfite, which places a very high BOD on the effluent system, but they liberate no carcinogenic amine and thus should significantly reduce the cost of effluent treatment.