Imide Carbonyl Group Research Articles

Origin of the Conformational Stability of Dirhodium(II) Tetrakis[N-phthaloyl-(S)-tert-leucinate] and Its Halogenated Derivatives.

In order to elucidate the origins of the stable structures of dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate] and the four derivatives with halogenated aromatic rings, the conformational stability and intramolecular interactions were investigated by DFT calculations. In all of these complexes, the conformation in which all ligands face in the same direction is the most stable. When adjacent ligands are in the same orientation, destabilization due to exchange repulsion is larger than that when they are in opposite orientations. However, this destabilizing effect is reversed by the sum of the stabilizing effects of the electronic and charge transfer interactions. The imide carbonyl group plays an important role in these stabilizing interactions. The negatively charged site and bond orbitals in the imide carbonyl group interact with the positively charged sites and bond orbitals in the aromatic ring, the carboxylate group, and the α-position of the carboxylate group in the adjacent ligands. In addition, the lone-pair orbitals of the halogen atoms contribute to conformational stabilization by interacting with the vacant orbitals in the adjacent ligands. However, the combinations of these charged sites or bond orbitals, which effectively contribute to the stabilization, are different for each complex.

Control over rotary motion and multicolour switching in 3-hydroxyphthalimide fluorophores: An interplay between AIE and ESIPT

In this paper, we demonstrate the ability of N-substituted 3-hydroxyphthalimides with pyridine and isoquinoline rings to perform multicolour switching by different stimuli. Restriction of the C–N rotary motion of the heterocycles allows control over their photoluminescence performance (PLQY = 54–65%) in water-induced aggregation by an additive interplay of excited-state proton-mediated processes in the aggregates. Restriction of the rotations by the affinity of the heterocyclic nitrogen atoms to Zn2+ and switching to new emission bands (PLQY = 8–29%) in solution and solid state were also achieved. Protonation of the pyridine/isoquinoline rings allows the formation of intramolecular hydrogen bonds with the imide carbonyl groups, resulting in restricted rotations. The protonated forms switch to strong blue emission due to local excitation of the protonated heterocycles, which are unable to undergo proton transfer. Understanding the interplay between both photophysical processes would allow the switching of emissions by multistimuli.

High-temperature adhesive properties of CF/PEKK composites applied fusion bonding and adhesive bonding

The chemical bonding of substrate and adhesive occurs in thermoplastic adhesive bonding, and the molecular deformation caused by the difference in chemical bonding affects the adhesive properties. Therefore, it is essential to investigate the correlation between the molecular deformation of interphase and the strength change behavior. As adhesive bonding involves the combination of two materials with different coefficients of thermal expansion, it is important to analyze the behavior at high temperatures. Therefore, to determine the effects of the molecular deformation of the interphase caused by differences in the adhesive type on the high-temperature performance when adhesive bonding is applied to thermoplastic composites, fusion and adhesive bonding were applied to carbon fiber/polyetherketoneketone thermoplastic composites. The lap shear strength test was conducted at three different temperatures to evaluate the adhesive performances. Scanning electron microscopy was used to determine the fracture mode and the molecular deformation of the interphase was analyzed by Fourier transform infrared spectroscopy. Temperature does not affect the strength of fusion bonded composites. When polyetheretherketone is used as an adhesive, the strength decreases as the temperature increases. When polyetherimide is used as an adhesive, the strength first increases at [Formula: see text]C and then decreases at [Formula: see text]C. The amount of C–O–C and C=C bond formation, diphenyl ketone group, and imide carbonyl group in the interphase followed the same trend as the strength.

A High-Rate Two-Dimensional Polyarylimide Covalent Organic Framework Anode for Aqueous Zn-Ion Energy Storage Devices

Rechargeable aqueous Zn-ion energy storage devices are promising candidates for next-generation energy storage technologies. However, the lack of highly reversible Zn2+-storage anode materials with low potential windows remains a primary concern. Here, we report a two-dimensional polyarylimide covalent organic framework (PI-COF) anode with high-kinetics Zn2+-storage capability. The well-organized pore channels of PI-COF allow the high accessibility of the build-in redox-active carbonyl groups and efficient ion diffusion with a low energy barrier. The constructed PI-COF anode exhibits a specific capacity (332 C g-1 or 92 mAh g-1 at 0.7 A g-1), a high rate capability (79.8% at 7 A g-1), and a long cycle life (85% over 4000 cycles). In situ Raman investigation and first-principle calculations clarify the two-step Zn2+-storage mechanism, in which imide carbonyl groups reversibly form negatively charged enolates. Dendrite-free full Zn-ion devices are fabricated by coupling PI-COF anodes with MnO2 cathodes, delivering excellent energy densities (23.9 ∼ 66.5 Wh kg-1) and supercapacitor-level power densities (133 ∼ 4782 W kg-1). This study demonstrates the feasibility of covalent organic framework as Zn2+-storage anodes and shows a promising prospect for constructing reliable aqueous energy storage devices.

Brønsted acid-mediated cyclization-dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines.

An efficient and alternative synthetic approach has been developed to prepare various N-(arylethyl)piperazine-2,6-diones from 4-benzenesulfonyliminodiacetic acid and primary amines using carbonyldiimidazole in the presence of a catalytic amount of DMAP at ambient temperature. Piperazine-2,6-diones are successfully transformed to pharmaceutically useful pyridopyrazines or pyrazinoisoquinolines and ene-diamides via an imide carbonyl group activation strategy using a Brønsted acid. Subsequent dehydrosulfonylation reactions of the ene-diamides, in a one pot manner, smoothly transformed them to substituted pyrazinones. A concise synthesis of praziquantel (1) has also been achieved through this method.

Why chiral tartaric imide derivatives give large helical twisting powers in nematic liquid crystal phases: substituent-effect approach to investigate intermolecular interactions between dopant and liquid crystalline molecules

ABSTRACTNovel C2-symmetric chiral dopant derivatives, namely, N-substituted (2R, 3R)-2,3-bis(4-(4-octyloxyphenyl)benzoyloxy)succinimides1a-h, were synthesised, and the effects of the N-substituent and imide-carbonyl groups on the helical twisting powers (HTPs) were investigated in two nematic liquid crystalline compounds, 4-n-pentyl-4ʹ-cyanobiphenyl (5CB) and N-(4-ethoxybenzylidene)-4-n-butylaniline (EBBA). As a result, it was clarified that the bulkiness of the N-substituents has a significant correlation with the HTPs, and the imide-carbonyl group interacts strongly with the cyano group of 5CB to give high HTPs in the nematic phases. However, it is assumed that the imide-carbonyl groups of the dopants do not have strong electrostatic attractive interactions with EBBA molecules in the nematic phase to afford the moderate HTPs.

ChemInform Abstract: Synthesis of (+)‐Harmicine.

A facile convergent access to the important indole alkaloid (+)-harmicine is described, starting from tryptamine and (R)-acetoxysuccinic anhydride via the corresponding acetoxysuccinimide in very good overall yield. Regioselective reduction of an unsymmetrical imide carbonyl group and acid-catalyzed stereoselective intramolecular cyclization were the key features involved. The directing group to induce asymmetry was finally detached via the corresponding iodide by using tributyltin hydride chemistry.

Thermally stimulated spontaneous current investigations in 75 MeV oxygen-ion-irradiated kapton-H polyimide

Thermally stimulated spontaneous currents in 75 MeV oxygen-ion-irradiated kapton-H polyimide samples sandwiched between similar (M–P–M) and dissimilar (M1–P–M2) electrodes in the temperature range of 20–250°C have been studied. Metals used as electrodes in the present investigations are having different work functions (Bi: 4.22, Al: 4.28, Cr: 4.37, Cu: 4.70 and Au: 5.1 eV). One maxima in the temperature region 30–60°C and other in the temperature region 100–120°C have been observed, termed as γ and β relaxations, respectively. γ-Relaxation is associated with the water absorption and β-relaxation is associated with the presence of dipoles in the material. The magnitude of the current depends on the type of electrode combinations used: either similar (M–P–M) or dissimilar (M1–P–M2) electrode systems. The value of current in M1–P–M2 combinations is more in comparison with M–P–M systems, as the internal potential difference developed in dissimilar electrodes is more as compared with the similar electrode system. The carbonyl groups present in the structure of kapton-H polyimide are the most affected group, due to the contact electrode system and ion irradiation. Aluminum atoms interact with imide carbonyl groups in kapton-H polyimide form carbonyl (>C═O)-metal complex. As a result of ion irradiation, demerization of carbonyl groups and formation of some new polar–subpolar groups take place. The moisture in ion-irradiated samples promotes the current magnitude via helping in transport or conduction of charge carriers through polyimide.

Synthesis of (+)-Harmicine

A facile convergent access to the important indole alkaloid (+)-harmicine is described, starting from tryptamine and (R)-acetoxysuccinic anhydride via the corresponding acetoxysuccinimide in very good overall yield. Regioselective reduction of an unsymmetrical imide carbonyl group and acid-catalyzed stereoselective intramolecular cyclization were the key features involved. The directing group to induce asymmetry was finally detached via the corresponding iodide by using tributyltin hydride chemistry.

Regulating Nucleation Kinetics through Molecular Interactions at the Polymer–Solute Interface

Heterogeneous nucleation is ubiquitous both in nature and in industrial practice; therefore, the ability to inhibit or enhance the kinetics of a crystallization process is essential in many scientific and technological areas. In order to better understand the role of surface functionality in regulating the nucleation rate, six commercially available polymers have been used as heteronucleants of acetaminophen (ACM) molecules: polydimethylsiloxane (PDMS) with siloxane functional groups Si–O–Si forming the backbone of silicones, partially fluorinated elastomer polyvinylidenedifluoride (PVDF), polystyrene (PS) having weak electron-donor phenyl rings, poly(n-buthyl methacrylate) (PnBMA) showing ester functionality, polyimide (PI) that includes both hydrogen-bond acceptor imide functionality and carbonyl groups, ethylene/acrylic acid (EAA) copolymer with carboxyl moiety. Experimental results from induction time statistics, van Oss–Chaudhury–Good model of surface energetics, and powder X-ray diffraction (PXRD) a...

N-(3-Chloro-1,4-dioxo-1,4-di-hydro-naph-thalen-2-yl)-N-propionylpropionamide.

In the title mol­ecule, C16H14ClNO4, the four essentially planar atoms of the imide group [r.m.s. deviation = 0.0286 (11) Å] form a dihedral angle of 77.36 (13)° with the naphtho­quinone group [maximun deviation = 0.111 (2) Å for the carbonyl O atom in the naphthalene 1-position] and the two imide carbonyl groups are oriented anti with respect to each other. In the crystal, mol­ecules are connected by weak C—H⋯O hydrogen bonds, as well as π–π stacking inter­actions [centroid–centroid distance = 3.888 (3) Å], forming a three-dimensional network.

N-Butanoyl-N-(3-chloro-1,4-dioxonaphthalen-2-yl)butanamide

In the title compound, C18H18ClNO4, the imide group with its two alkyl substituents is approximately perpendicular to the plane of the naphtho­quinone ring system [dihedral angle = 78.5 (1)°]. Further, the imide carbonyl groups are oriented in an anti sense. In the crystal, the substituted naphtho­quinone rings form π–π stacks in the a-axis direction [perpendicular centroid–centroid distance = 3.209 (2) Å and slippage = 4.401 Å].

Extended π-Conjugated Molecules Derived from Naphthalene Diimides toward Organic Emissive and Semiconducting Materials

In this paper, a new synthetic way to modify naphthalene diimide (NDI) at "shoulder" positions is reported. The key step of the transformation is the intramolecular cyclization involving ethynyl and imidecarbonyl groups. The structure of the intermediate pyrylium cation was confirmed by X-ray crystal structural analysis. New conjugated molecules 1a-g were successfully synthesized in acceptable yields. Their absorption and fluorescence spectra were measured. Among them 1c-f are strongly emissive in solutions. Furthermore, 1b-f are also fluorescent in their solid states; in particular, 1b exhibits a typical aggregation-induced enhanced emission feature. Yellow-emissive microfibrils of 1d show potential optical waveguide behavior. HOMO/LUMO energies of 1a-f were determined based on their cyclic voltammograms. The results also reveal that HOMO/LUMO energies of these new conjugated molecules are influenced by the two flanking moieties. Notably, the thin film of 1c that is emissive shows p-type semiconducting behavior with hole mobility up to 0.0063 cm(2) V(-1) s(-1) based on the transfer and output characteristics of the OFET (organic field effect transistor).

Construction of tetrahydro-β-carboline skeletons via Brønsted acid activation of imide carbonyl group: syntheses of indole alkaloids (±)-harmicine and (±)-10-desbromoarborescidine-A

Indole, a π-nucleophile, reacts with Brønsted acid activated imide carbonyl group in an intramolecular fashion via a 6-exo-trig cyclization, to deliver a condensed tetrahydro-β-carboline unit. This methodology is effectively applied to assemble the tetrahydro-β-carboline skeleton containing alkaloids such as harmicine and 10-desbromoarborescidine-A.

Brønsted acid assisted activation of imide carbonyl group: regioselective synthesis of isoindoloisoquinolinone alkaloid (±)-nuevamine

Activation of imide carbonyl group with trifluoromethanesulfonic acid facilitates the intramolecular cyclization of phenethylphthalimides to give a fused isoindoloisoquinolinone skeleton. The first one pot regioselective synthesis of isoindoloisoquinolinone alkaloid (±)-nuevamine has been successfully executed using this methodology.

ChemInform Abstract: An Unusual Reactivity of BBr3: Accessing Tetrahydroisoquinoline Units from N‐Phenethylimides.

AbstractA simple methodology to construct the tetrahydroisoquinoline containing skeleton through electrophilic activation of imide carbonyl group of N‐phenethylimides using BBr3 as Lewis acid is developed.

Excited-State Intramolecular Proton Transfer in Imide Compounds and its Application to Control the Emission Colors of Highly Fluorescent Polyimides

A new molecular design concept for colorless and multicolor light-emitting polyimides (PIs) based on excited-state proton transfer is proposed. The ultraviolet−visible optical absorption spectra and fluorescence spectra of PIs containing hydroxy groups in their anhydride moieties and their corresponding imide compounds were extensively investigated. N-Cyclohexyl-3-hydroxyphthalimide (3HNHPI), which forms intramolecular hydrogen bonding between the hydroxy group and imide carbonyl group, exhibited an excited-state intramolecular proton transfer (ESIPT) emission at 534 nm with excitation at 332 nm having a large Stokes’ shift of 11394 cm−1. The highly fluorescent PIs, prepared from 4,4′-oxidiphthalic dianhydride (ODPA) and 4,4′-diaminocyclohexylmethane (DCHM) end-capped with 3-hydroxyphthalic anhydride, are colorless and exhibited two characteristic fluorescence peaks at 400 and 530 nm with excitation at 340 nm. These PIs showed gradated multicolor emission (blue, light-blue, white, and light-green) depending on the amount of fluorescent termini while maintaining colorless and transparence. It was clarified that ESIPT emission is a useful tool for controlling the absorption and fluorescence properties of PIs.

Comparative Diels−Alder Reactivities within a Family of Valence Bond Isomers: A Biomimetic Total Synthesis of (±)-UCS1025A

A synthesis of the structurally fascinating fungal metabolite UCS1025A (1) was accomplished. It features a likely biomimetic approach to the octalin subunit via an intramolecular Diels-Alder (IMDA) reaction of a putative triene precursor (2), preceded by an efficient construction of the bisheteratriquinane subunit within that compound. Specifically, an intramolecular silyl triflate-induced cyclization of an in situ-generated silyl ketene acetal onto an imide carbonyl group (e.g., 7 to 8) was developed. The IMDA relative reactivities of a family of valence bond isomers, each differing in the precise nature of the dienophilic subunit, were determined. Under biologically relevant conditions (D2O, pH 7.2 buffer, ca. 25 degrees C), triene 2, via its lactone ring-opened congener, underwent very fast (t1/2 = 10 min) conversion to the ring-opened forms of 1 (i.e., 5a) and the tetraepimeric, alternative endo-adduct, 3 [i.e., (tetraepi)-5a].

Diastereoselective synthesis of 10b-substituted hexahydropyrroloisoquinolines from l-tartaric acid. Creation of a quaternary carbon stereocentre via N-acyliminium ion cyclization

A simple, three-step synthesis of 10b -substituted-hexahydropyrroloisoquinolines 12– 17 starting from an L-tartaric acid derived imide is described. The methodology presented employs the addition of a Grignard reagent to the imide carbonyl group, followed by a one-pot acetylation–cyclization sequence. The crucial step, an acid-catalyzed carbon–carbon bond forming reaction via an N-acyliminium ion offers moderate to high stereoselectivity, which has been shown to be strongly dependent on the size of the R-substituent. The mixtures of pyrroloisoquinolines obtained can be separated as enantiomerically pure 2-silyloxy-derivatives.

(5S,6R)-4,5-Dimethyl-6-phenyl-3-trimethylacetyl-2H-1,3,4-oxadiazinan-2-one

The crystal structure of the title compound, C16H22N2O3, was undertaken in the course of a study on an acyl­ated pseudoephedrine-derived 1,3,4-oxadiazinan-2-one. The conformation adopted by this heterocycle is a contorted half-chair, in which the imide carbonyls are arranged with the carbonyl groups oriented approximately syn to each other. The torsion angle between the imide carbonyl groups is 37.6 (2)°.