Acetylacetone was successfully used as a precursor of 4-aminomethylpyrazoles and 4-aminomethylisoxazoles in a two step process at ambient temperature. In the first step, acetylacetone was transformed to the corresponding hexahydropyrimidines (1,3-diazinanes) via two consecutive one-pot Mannich aminomethylations. Hexahydropyrimidines were then treated with hydrazine, phenylhydrazine, and hydroxylamine, respectively, to obtain the corresponding 4-aminomethylpyrazoles and 4-aminomethylisoxazoles in good yields. The hexahydropyrimidine ring decomposed providing the title compounds and a reasonable mechanism has been proposed. 相似文献
The recent global pandemic and its tremendous effect on the price fluctuations of crude oil illustrates the side effects of petroleum dependency more evident than ever. Over the past decades, both academic and industrial communities spared endless efforts in order to replace petroleum-based materials with bio-derived resources. In the current study, a series of shape memory polymer composites (SMPC's) was synthesized from epoxidized vegetable oils, namely canola oil and castor oil fatty acids (COFA's) as a 100% bio-based polyol and isophorone diisocyanate (IPDI) as an isocyanate using a solvent/catalyst-free method in order to eventuate polyurethanes (PU's). Thereafter, graphene oxide (GO) nanoplatelets were synthesized and embedded in the neat PU in order to overcome the thermomechanical drawbacks of the neat matrix. The chemical structure of the synthesized components, as well as the dispersion and distribution levels of the nanoparticles, was characterized. In the following, thermal and mechanical properties as well as shape memory behavior of the specimens were comprehensively investigated. Likewise, the thermal conductivity was determined. This study proves that synthesized PU's based on vegetable oil polyols, including graphene nanoparticles, exhibit proper thermal and mechanical properties, which make them stand as a potential candidate to compete with traditional petroleum-based SMPC's. 相似文献
Let be a minimal monomial Togliatti system of forms of degree d. In [4], Mezzetti and Miró-Roig proved that the minimal number of generators of lies in the interval . In this paper, we prove that for and , the integer values in cannot be realized as the number of minimal generators of a minimal monomial Togliatti system. We classify minimal monomial Togliatti systems of forms of degree d with or 3n (i.e. with the minimal number of generators reaching the border of the non-existence interval). Finally, we prove that for , and there exists a minimal monomial Togliatti system of forms of degree d with . 相似文献
Co–Fe bimetallic nanoparticles-affixed polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) nanofiber membrane is fabricated using the electrospinning and chemical reduction techniques. The semicrystalline polymeric backbone decorated with the highly crystalline Co–Fe bimetallic nanoparticles enunciates the mechanical integrity, while the incessant and swift electron mobility is articulated with the consistent dissemination of bimetallic nanoparticles on the intersected and multi-layered polymeric nanofibers. The diffusion and adsorption of glucose are expedited in the extended cavities and porosities of as-formulated polymeric nanofibers, maximizing the glucose utilization efficacy, while the uniformly implanted Co4+/Fe3+ active centers on PVdF-HFP nanofibers maximize the electrocatalytic activity toward glucose oxidation under alkaline regimes. Thus, the combinative sorts including nanofiber and nanocomposite strategies of PVdF-HFP/Co–Fe membrane assimilate the enzyme-less electrochemical glucose detection concerts of high sensitivity (375.01 μA mM?1 cm?2), low limit of detection (0.65 μm), and wide linear range (0.001 to 8 mM), outfitting the erstwhile enzyme-less glucose detection reports. Additionally, the endowments of high selectivity and real sample glucose-sensing analyses of PVdF-HFP/Co–Fe along with the binder-less and free-standing characteristics construct the state-of-the-art paradigm for the evolution of affordable enzyme-less electrochemical glucose sensors.
Molecular Diversity - In the present work, a series of bisbenzazole derivatives were designed and synthesized as antiproliferative agents. The antiproliferative activity of these compounds was... 相似文献
A recently discovered 2D transition titanium metal carbides also called as MXenes (Ti3C2Tx)-based nanocomposite was prepared with Cu2O through wet precipitation technique, and these materials were further developed as the electrode for sensing glucose by chronoamperometry technique. The prepared MXene-Cu2O (Ti3C2Tx-Cu2O) nanocomposite was characterized by XRD, FTIR, UV–Vis spectroscopy, FE-SEM, EDAX, and Raman spectroscopy. Morphological studies of the composites revealed that the micro-octahedral shape of Cu2O is distributed on the surface of MXene with size larger than bare Cu2O. Further, the prepared composite material was fabricated as a sensing probe, and the electrochemical activities were examined by cyclic voltammetric analysis (CV) and chronoamperometric (CA) methods. From the CV and CA investigation, the current response was higher for the composite than the bare material (Cu2O & MXene) in the presence of glucose. The amperometric investigation of MXene-Cu2O composite for the detection of glucose shows a broad linear range (0.01–30 mM) with a sensitivity of 11.061/μAmM cm?2 and a detection limit of 2.83 μM. Further, the fabricated sensor exhibits good selectivity with interfering species like NaCl, fructose, sucrose, urea, ascorbic acid, lactose, short response time, stability, good reproducibility, and compatibility with human serum sample. From the investigation, the prepared MXene-Cu2O composite is a good candidate for the direct detection of glucose molecules and is also well suitable for clinical diagnosis. 相似文献