scholarly journals Synthesis and Characterization of Fully Conjugated Ladder Naphthalene Bisimide Copolymers

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 790 ◽  
Author(s):  
Feng Liu ◽  
Yonggang Wu ◽  
Chao Wang ◽  
Junshu Ma ◽  
Fan Wu ◽  
...  

Fully conjugated ladder copolymers have attracted considerable attention due to their unique fused-ring structure and optoelectronic properties. In this study, two fully conjugated ladder naphthalene diimide (NDI) copolymers, P(NDI-CZL) and P(NDI-TTL) with imine-bridged structures are presented in high yields. Both of the two copolymers have good solubility and high thermal stability. The corresponding compounds with the same structure as the copolymers were synthesized as model system. The yields for each step of the synthesis of the model compounds are higher than 95%. These results suggest that P(NDI-CZL) and P(NDI-TTL) can be synthesized successfully with fewer structural defects. The structures and optoelectronic properties of compounds and copolymers are investigated by NMR, fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), and cyclic voltammetry (CV). Both in solution and as a thin film, the two copolymers show two UV-vis absorption bands (around 300–400 nm and 400–750 nm) and a very weak fluorescence. The collective results suggest that the two fully conjugated ladder copolymers can be used as potential acceptor materials.

2013 ◽  
Vol 781-784 ◽  
pp. 499-502
Author(s):  
Chun Hua Qi ◽  
Xiao Long Lei ◽  
Xiao Xia Sun ◽  
Yu Hu

A simple and efficient synthetic procedure of 2',7'-dibromo-2,3,6,7-tetraethoxy-9,9'-spirobi [fluoren has been developed. The new monomer of 2',7'-dibromo-2,3,6,7-tetraethoxy-9,9'-spirobi [fluoren has been synthesized in high yields over five steps from readily available starting materials. The new monomer has good solubility in organic solvents such as chloroform, methylene chloride, tetrahydrofuran, ethyl acetate and so on.


2013 ◽  
Vol 781-784 ◽  
pp. 444-447 ◽  
Author(s):  
Xiao Xia Sun ◽  
Xiao Xiao Zhuang ◽  
Yu Hu

Monomers based on 2,1,3-benzothiadiazole bearing solubilizing side chains have been synthesized in high yields over four steps from readily available starting materials. A multistep synthesis of the electron-poor 5,6-bis (heptyloxy) benzo [[1,2,thiadiazole are presented. The new deficient acceptor has good solubility in organic solvents to permit an appropriate coating process.


2012 ◽  
Vol 174-177 ◽  
pp. 692-696 ◽  
Author(s):  
Xiao Xia Sun ◽  
Xiao Xiao Zhuang ◽  
Yu Hu

Heterocyclic monomers based on 2,1,3-benzothiadiazole bearing solubilizing side chains have been synthesized in high yields over four steps from readily available starting materials. The new dificient acceptor has good solubility in organic aolvents to permit an appropriate coating process. Two soluble donor-acceptor π-conjugated oligomers comprising electron-rich thiophenes the electron-deficient EDOBT have been carefully investigated.


Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.


Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.


2018 ◽  
Vol 21 (7) ◽  
pp. 526-532 ◽  
Author(s):  
Zahra Abdi Piralghar ◽  
Mohammad Mahmoodi Hashemi ◽  
Ali Ezabadi

Aim and Objective: In this work, we synthesized and characterized a novel Brönsted acidic ionic liquid from the reaction of N, N, N’, N’-tetramethylethylenediamine with chlorosulfonic acid and explored its catalytic activity in 1, 8-dioxo-octahydroxanthenes synthesis. Materials and Methods: Dimedone, aryl aldehydes, and the ionic liquid as the catalyst were reacted under solvent-free conditions. The progressive of the reaction was monitored by a thin layer of chromatography (ethyl acetate/n-hexane = 1/5). All products were characterized as the basis of their spectra data and melting point by comparison with those reported in the literature. Results: The prepared ionic liquid was successfully applied in the synthesis of 1, 8-dioxooctahydroxanthenes in good to high yields on the reaction of aryl aldehyde and dimedone at 120oC under solvent-free conditions. Conclusion: This research demonstrates that the catalyst is impressive for 1, 8-dioxo-octahydroxanthenes synthesis under solvent-free conditions.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Adolfo Bucio ◽  
Rosario Moreno-Tovar ◽  
Lauro Bucio ◽  
Jessica Espinosa-Dávila ◽  
Francisco Anguebes-Franceschi

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.


BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi Bi Fatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi

AbstractNano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.


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