99-98-9Relevant articles and documents
-
Livingston,Pariser
, p. 2944,2948,2949 (1956)
-
Developments in Dynamic Covalent Chemistries from the Reaction of Thiols with Hexahydrotriazines
Wojtecki, Rudy J.,Jones, Gavin O.,Yuen, Alexander Y.,Chin, Willy,Boday, Dylan J.,Nelson, Alshakim,García, Jeannette M.,Yang, Yi Yan,Hedrick, James L.
, p. 14248 - 14251 (2015)
Dynamic covalent chemistries have garnered significant attention for their potential to revolutionize technologies in the material fields (engineering, biomedical, and sensors) and synthetic design strategies as they provide access to stimuli responsiveness and adaptive behaviors. However, only a limited number of molecular motifs have been known to display this dynamic behavior under mild conditions. Here, we identified a dynamic covalent motif - thioaminals - that is produced from the reaction of hexahydrotriazines (HTs) with thiols. Furthermore, we report on the synthesis of a new family of step-growth polymers based on this motif. The condensation efficiently proceeds to quantitative yields within a short time frame and offers versatility in functional group tolerance; thus, it can be exploited to synthesize both small molecule thioaminals as well as high molecular weight polymers from the step-growth polymerization of HTs with dithiols. Careful evaluation of substituted HTs and organic thiols supported by DFT calculations led to a chemically diverse library of polymers based on this motif. Finally, dynamic substitution reactions were employed toward the facile preparation of functional oligomers and macromolecules. This dynamic covalent motif is particularly attractive for a range of applications that include material design and drug delivery due to the economic feasibility of synthesis.
Naphthalimide-Based Azo-Functionalized Supramolecular Vesicle in Hypoxia-Responsive Drug Delivery
Sarkar, Deblina,Chowdhury, Monalisa,Das, Prasanta Kumar
, p. 3480 - 3492 (2022/03/27)
Supramolecular materials that respond to external triggers are being extensively utilized in developing spatiotemporal control in biomedical applications ranging from drug delivery to diagnostics. The present article describes the development of self-assembled vesicles in 1:9 (v/v), tetrahydrofuran (THF)-water by naphthalimide-based azo moiety containing amphiphile (NI-Azo) where azo moiety would act as the stimuli-responsive junction. The self-assembly of NI-Azo took place through H-type of aggregation. Microscopic and spectroscopic analyses confirmed the formation of supramolecular vesicles with a dimension of 200-250 nm. Azo (-N=N-) moiety is known to get reduced to amine derivatives in the presence of the azoreductase enzyme, which is overexpressed in the hypoxic microenvironment. The absorbance intensity of this characteristic azo (-N=N-) moiety of NI-Azo (1:9 (v/v), THF-water) at 458 nm got diminished in the presence of both extracellular and intracellular bacterial azoreductase extracted from Escherichia coli bacteria. The same observation was noted in the presence of sodium dithionite (mimic of azoreductase), indicating that azoreductase/sodium dithionite induced azo bond cleavage of NI-Azo, which was confirmed by matrix-assisted laser desorption ionization time-of-flight spectrometric data of the corresponding aromatic amine fragments. The anticancer drug, curcumin, was encapsulated inside NI-Azo vesicles that successfully killed B16F10 cells (cancer cells) in CoCl2-induced hypoxic environment owing to the azoreductase-responsive release of drug. The cancer cell killing efficiency by curcumin-loaded NI-Azo vesicles in the hypoxic condition was 2.15-fold higher than that of the normoxic environment and 2.4-fold higher compared to that of native curcumin in the hypoxic condition. Notably, cancer cell killing efficiency of curcumin-loaded NI-Azo vesicles was 4.5- and 1.9-fold higher than that of noncancerous NIH3T3 cells in normoxic and hypoxic environments, respectively. Cell killing was found to be primarily through the early apoptotic pathway.
Synthesis and characterization of polyaniline/nickel oxide composites for fuel additive and dyes reduction
Jamil, Saba,Ahmad, Zunaira,Ali, Muhammad,Rauf Khan, Shanza,Ali, Sarmed,Amen Hammami, Mohamed,Haroon, Muhammad,Saleh, Tawfik A.,Ramzan Saeed Ashraf Janjua, Muhammad
, (2021/05/13)
Polyaniline (PANI) and Polyaniline/Nickel oxide (PANI/NiO) composites are prepared to use as a potential catalyst, by Chemical oxidation method using ammonium persulfate (NH4)2S2O8)) as an oxidant. Nickel oxide (NiO) nanopartiles are prepared by Sol-gel method. The synthesized products were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction technique (XRD). The prepared PANI/NiO composites are used as additive with different concentrations in diesel to investigate their efficiency as fuel additive. The catalytic properties are studied by using the synthesized products as catalyst for reduction of dyes in aqueous media. Sodium borohydride (NaBH4) is used as reducing agent. Linear relationships are obtained between time and ln(A0/At) for Methyl orange and Methylene blue. Kapp values were obtained for three catalysts showed the increasing trend of reduction for both dyes as, PANI NiO PANI/NiO composites. Experimental data analysis proved PANI/NiO composites to be efficient catalysts and fuel additive as compared to PANI and NiO.
Green synthesized AgNPs decorated on Ketjen black for enhanced catalytic dye degradation
Ramaraghavulu, Rajavaram,Rao, V. Koteswara,Devarayapalli,Yoo, Kisoo,Nagajyothi,Shim, Jaesool
, p. 637 - 648 (2020/10/15)
The green synthesis of nanoparticles using plant-based materials as an alternative to chemical and physical routes provides economic and environmental benefits. In the present study, silver nanoparticles (AgNPs) were fabricated using Pseudocydonia sinensis fruit extract. The fabricated NPs were then decorated on commercial Ketjen black-300 (AgNPs@KB-300) and Ketjen black-600 (AgNPs@ KB-600). The synthesized materials were characterized via XRD, FTIR, XPS, SEM-EDX, and HR-TEM studies. The SEM and HR-TEM results revealed that the synthesized AgNPs were spherical and successfully decorated on KB-300 and KB-600. Additionally, the catalytic ability of the synthesized samples during the degradation of methyl orange in the presence of NaBH4 was studied. Notably, the catalytic activity of AgNPs@ KB-600 was higher than that of AgNPs@ KB-300.