Six-membered Imide Research Articles

Extension of Highly Efficient Alcohol-promoted Rearrangement into One-pot Domino Palladium-catalyzed Carbonylation for Sterically Crowded Aromatic Six-membered Imides

Extension of Highly Efficient Alcohol-promoted Rearrangement into One-pot Domino Palladium-catalyzed Carbonylation for Sterically Crowded Aromatic Six-membered Imides

Autocatalytic one-step high-temperature synthesis of carboxylated polyimides for in-situ high performance applications

Carboxylated polyimides (CxPIs) represent a great potential for gas separation membranes, highly thermostable coatings and fibers, ion-conducting materials, aerogels, (nano)composites, etc. However a prolonged and expensive two-stage method proceeding through the formation of an unstable poly(amic acid) and subsequent thermal or chemical imidization is traditionally used for the synthesis of CxPIs. Herein a new strategy consisting in one-step high-temperature synthesis of CxPIs based on 3,5-diaminobenzoic acid (DABA), the carboxyl groups of which provide an autocatalytic effect, in N-methyl-2-pyrrolidone (NMP) is presented. The effect of DABA content on the formation and properties of CxPIs is studied. It is established that high-molecular-weight CxPIs (Mw = 158–356 kDa) with five- and more stable six-membered imide rings from various dianhydrides of aromatic tetracarboxylic acids and diamines as comonomers are synthesized within 1–4 h of the reaction even with 25 mol% of DABA content. Additional catalyst-free synthesis of CxPIs in NMP allows to use the solutions obtained in situ for the production of various materials. In particular, CxPI-varnishes form the primary protective coating of the optical fiber superior to the commercial analogue in terms of its manufacturing technology, thermal and hydrolytic stability, which provides more reliable and long-term operation.

Naphthalenothiophene Imide-Based Polymer Donor for High-Performance Polymer Solar Cells

Naphthalenothiophene imide (NTI), bearing six-membered imide and a five-membered aromatic ring, was synthesized by a one-step Suzuki reaction in high yield. NTI is an electron-deficient monomer tha...

Naphthalenothiophene imide-based polymer exhibiting over 17% efficiency

Summary Developing novel electron-deficient monomers is crucially important for the future development of non-fullerene organic solar cells. Here, we report a new electron-deficient monomer naphthalenothiophene imide (NTI) and NTI-based copolymers PNTB and PNTB-2T. The strong electron-withdrawing ability of NTI could effectively lower the HOMO level of the polymer that facilitates the tuning of the polymer’s physical properties while simultaneously maintaining the low-lying HOMO value. Polymer chains modification by introducing extra thiophenes results in the closed π−π stacking and ordered polymer chain packing of PNTB-2T and is proven to be an effective strategy to increase the device performance. Thus, solar cell devices for PNTB-2T:Y6 exhibit an efficiency of 16.72%, which is further enhanced to 17.35% by the third component PC71BM, whereas that for PNTB:Y6 is only 3.81%. Importantly, PNTB-2T-based devices exhibit excellent batch-to-batch reproducibility. These features make this family of polymer donors very promising and the design strategies will enlighten future development of high-performance polymer donors for organic solar cells (OSC).

Synthesis, structures and stereodynamic behavior of pentacoordinate (O→Si)-Chelate Difluoro(methyl)silylmethyl derivatives of amides and imides

The structures and stereodynamic behavior of (O→Si)-chelate methyldifluorosilanes in solutions were studied by multinuclear (1H, 13C, 19F, 29Si) and 2D (COSY, HETCOR 1H, 13C) NMR spectroscopy. The range of studied complexes included amides RC(O)N(R')CH2SiMeF2 [R = Ph, R' = H (1a); R = R' = Me (1b); R = Me, R' = CHMePh (1c)], lactams LCH2SiMeF2 (L = 2-oxoazepan-1-yl (2a), 2,2-dimethyl-4-oxo-2H-benzo[1,3]oxazin-3-yl (2b) or 4-methyl-2-oxoquinolin-1-yl (2c)] and the six-membered imide Im6CH2 [2,6-dioxopiperidin-1-yl (3)]. The pentacoordination of silicon atoms in all studied compounds was confirmed by NMR study in solutions and single-crystal X-ray studies of complexes 1c, 2a, 2c and 3. The temperature dependency observed for the 19F NMR signals in solution was explained by the ligand exchange in the coordination environment of silicon atoms (permutational isomerization) and used for determining the activation parameters of this process by 19F DNMR. Quantum-chemical calculations for various isomers of complexes 1c, 2a, 2c and 3 suggested the "turnstile rotation" as the most likely mechanism for the observed stereodynamic processes.

Aminoketyl Radicals in Organic Synthesis: Stereoselective Cyclization of Five- and Six-Membered Cyclic Imides to 2-Azabicycles Using SmI2-H2O.

Synthetic application of aminoketyl radicals [R-C(•)(O(-))NR'R″] formed by a direct electron capture into the amide bond is limited. Herein, we demonstrate addition of aminoketyl radicals to unactivated alkenes using SmI2-H2O as a crucial promoter based on the generic five- and six-membered imide template. Notably, this method enables direct access to aminoketyl radicals with wide-ranging applications in synthesis for the formation of C-C bonds adjacent to nitrogen via polarity reversal.

Photo-optical and electrochemical behavior of novel heterocyclic copoly(naphthylimide-amide)s

This study is concerned with the synthesis and properties of new soluble quinoxaline-containing copoly(naphthylimide-amide)s having different flexible units such as ether, hexafluoroisopropylidene or diphenylsilane, in which the six-membered imide cycle is directly connected to the amide unit through a N-N bond. The polymers were successfully synthesized through the Yamazaki-Higashi polycondensation reaction of a mixture 1:1 of naphthalene-N,N’-bis(imido-amine) and 4,4′-{1,4-phenylene-bis[(3-phenyl-2,7-quinoxalinediyl)oxy]}dianiline or 4,4′-{oxy-bis[4,1-phenylene(3-phenyl-2,7-quinoxalinediyl)oxy]}dianiline with 4,4′-hexafluoroisopropylidene-bis(benzoic) acid, 4,4′-diphenylsilane-bis(benzoic) acid or with 4,4′-oxy-bis(benzoic) acid. These poly(imide-amide)s exhibited good solubility in common aprotic solvents, and the resulting polymer solutions were processed into amorphous thin films with homogeneous and neat surfaces. Their thermal characterization indicated a moderate to high thermal stability and no glass transition. The photoluminescence study of polymers both in solution and film state showed their ability for blue light color emission. The HOMO and LUMO energy levels were calculated by using cyclic voltammetry and UV–vis spectroscopy data, showing good electron injection and transport characteristics.

Electron-Transfer Reduction Properties and Excited-State Dynamics of Benzo[ghi]peryleneimide and Coroneneimide Derivatives

A series of benzo[ghi]perylene and coronene derivatives substituted by electron-withdrawing imide and ester groups were systematically synthesized considering (i) number of imide and ester groups, (ii) five- and six-membered imide groups, and (iii) the peripheral positions. The spectroscopic, electrochemical, and photophysical properties of these molecules were investigated in full detail by steady-state and time-resolved spectroscopy, cyclic voltammetry, quantum yield measurements of fluorescence and intersystem crossing, electron spin resonance (ESR), and density functional theory calculations. The synthetic introduction of proper substituents on the polycyclic aromatic hydrocarbon ring therefore enables us to successfully control the electrochemical and photophysical behaviors. The steady-state absorption and fluorescence spectra also become red-shifted and broadened as compared to those of reference unsubstituted benzo[ghi]perylene and coronene. Regarding the electrochemistry, with an increase in the ...

New azomethine-phthalic diimides: Synthesis and thermal, optical and electrochemical characterization

A new diamine with phthalic diimide moiety, i.e. N,N′-bis(4-amino-2,3,5,6-tetramethylphenyl)phthalene-1,4-dicarboxyimide was synthesized and applied for condensation with 4-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoroundecyloxy)benzaldehyde and 4-octadecyloxybenzaldehyde, which resulted in two new azomethine-phthalic diimides (AZ-PDIs). Thermal, optical and electrochemical properties of AZ-PDIs were discussed in relation to their analogous containing instead of five-membered six-membered imide rings (AZ-NDIs) described in our previous work. The phase behavior of AZ-PDIs examined by differential scanning calorimetry (DSC) and polarized optical microscopy (POM) confirms their liquid crystalline properties in wide range of temperatures. AZ-PDIs do not show decomposition below 400°C as was found based on thermogravimetric analyses (TGA). Optical properties of the prepared compounds were investigated by UV–vis and photoluminescence (PL) measurements. Azomethine-phthalic diimides emitted blue light with emission maximum (λem) at ca. 446–492nm contrary to azomethine-naphthalene diimides which emitted green light and λem was at 536 and 540nm. The obtained compounds are electrochemically active and undergo reversible reduction and oxidation as evidenced by differential pulse voltammetry (DPV). The azomethine-phthalic diimides exhibited low electrochemical band gap ca. 1.68eV being promising for optoelectronic applications.

Synthesis and Characterization of 2,8-Diazaperylene-1,3,7,9-tetraone, a New Anthracene Diimide Containing Six-Membered Imide Rings

A successful synthesis of novel diimides, namely anthracene diimide containing six-membered imide rings, with potential application in organic electronics is reported. The single crystal of 5a exhibits a close interplanar spacing of 3.45 Å between molecules in a stack.

Synthesis of unexpected six-membered imides by free-radical carbocyclisation on carbohydrate templates

Free-radical reactions of amido-esters anchored to a carbohydrate derived from methyl α- d-glucopyranoside afforded unexpected six-membered cyclic imides. Their structures were elucidated by ESI-MS/MS and NMR spectral analyses, and a mechanism for the formation of these imides is proposed.

The photodecomposition of cyclic N-bromo imides: evidence for stereoelectronic control in intramolecular hydrogen transfer in imidyl radicals

In order to examine the reactivities and configurations of imidyl radicals, several cyclic N-bromo imides possessing five- or six-membered imide rings have been photolytically decomposed in the presence of 1,1-dichloroethene in methylene chloride in order to scavenge bromine atoms and bromine. The five-membered N-bromo imides and (±)-N-bromocamphorimide undergo ring opening to afford products derived from C-bromo acyl isocyanates. While the corresponding imidyl radicals abstract a hydrogen atom from methylene chloride, none of them undergo intramolecular H-atom abstraction to effect an intramolecular hydrogen–bromine exchange reaction, even when there are suitably located C–H bonds at a fifth (or sixth) position that can overlap the π-orbital of the imidyl radicals. This phenomenon clearly reveals the presence of Stereoelectronic controls on the intramolecular H-abstraction of imidyl radicals, and indicates that the reactive state of imidyl radicals does not possess the Π-electronic configuration. We conclude that imidyl radicals possess the Iµ-electronic configuration in their reactive state (which is probably the ground state). The intramolecular addition of a C-radical centre to an isocyanate group is established; this indicates that the reversibility of the ring-opening reaction of imidyl radicals is controlled by steric strains among other factors. Because of the presence of reactive allylic hydrogens, the N-bromo imide (10) upon photolysis forms the C-bromo compounds (11) efficiently by a bromine atom chain process which is retarded by the presence of a better Br˙ scavenging alkene.

ChemInform Abstract: THE SULFENYLATION OF SUBSTITUTED IMINES

AbstractAus (I) werden die Sulfenylierungsprodukte (II) hergestellt; aus (IIIa) erhält man analog (IIIb).

Synthesis and investigation of poly(benzimidazole imides) based on new di-imidodicarboxylic acids

Members of a new class of compounds, di-imidodicarboxylic acids, containing six-membered imide rings, have been synthesized by reacting 4-carboxynaphthalic anhydride with aromatic diamines. Polycondensation of these acids with aromatic tetramines in polyphosphoric acid produced poly(benzimidazole imides), notable for their high resistance to acids and bases. Some properties of these polymers were investigated.

ChemInform Abstract: MODEL EXPERIMENTS ON THE CONSTRUCTION OF THE ABE RING SYSTEM OF HETISINE TYPE DITERPENE ALKALOIDS

AbstractDurch Alkylierung der Nitrile (I) werden die Methyl‐ (IIIa) bzw. Allyl‐Derivate (IIIb) erhalten.