Zn (II)‐Schiff base covalently anchored to CaO@SiO
<sub>2</sub>
: A hybrid nanocatalyst for green synthesis of 4
<i>H</i>
‐pyrans
作者:Fatemeh Sameri、Mohammad Ali Bodaghifard、Akbar Mobinikhaledi
DOI:10.1002/aoc.6394
日期:2021.11
In this study, the Zn (II)-Schiff basecovalentlyanchored onto the surface of CaO@SiO2 nanoparticles. The structure of this hybrid nanomaterial (CaO@SiO2-NH2-Sal-Zn) was characterized using the analytical techniques such as Fourier transform infrared spectroscopy, field emission-scanning electron microscopy, X-ray powder diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscopy
Ag/TiO2 nano thin films was found to be efficient and green heterogeneous catalyst for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives via a one-pot three-component reaction between 3-methyl-1H-pyrazol-5(4H)-one or 3-methyl-1(phenyl)-pyrazol-5(4H)-one, aldehydes and malononitrile at room temperature. Ag/TiO2 and TiO2 films were prepared by spray pyrolysis technique and the effect of substrate temperature and silver incorporation on optical, morphological and structural properties were investigated by XRD, AFM, spectrophotometry and photoluminescent spectroscopy. The results of this study shows adding of Ag to TiO2 films increased the optical absorption due to plasmonic behavior of Ag free electrons. XRD analysis was revealed the Hexagonal structure with Anatase phase and 101 prefer crystal orientation which is prefer phase for photocatalyst applications.
Ag/TiO2 纳米薄膜被发现是一种高效且绿色的异相催化剂,可通过在室温下进行的三组分反应合成二氢吡喃[2,3-c]吡唑衍生物,该反应涉及 3-甲基-1H-吡唑-5(4H)-酮或 3-甲基-1(苯基)-吡唑-5(4H)-酮、醛和氨基乙腈。Ag/TiO2 和 TiO2 薄膜采用喷雾热解技术制备,研究了基底温度和银掺入对其光学、形态和结构性质的影响,采用X射线衍射(XRD)、原子力显微镜(AFM)、光谱光度法和荧光光谱法进行分析。本研究结果表明,向 TiO2 薄膜中添加 Ag 增加了光学吸收,这是由于 Ag 自由电子的等离子体行为。XRD 分析显示出六角结构,具有锐钛矿相和以101为优选晶体取向,这一相是光催化应用的优选相。
Nano-titania-supported Preyssler-type heteropolyacid: An efficient and reusable catalyst in ultrasound-promoted synthesis of 4H-chromenes and 4H-pyrano[2,3-c]pyrazoles
An efficient and convenient procedure has been described for one-pot multi-component synthesis of tetrahydrobenzo[b]pyrans known as 4H-chromenes and 1,4-dihydropyrano[2,3-c]pyrazole derivatives in the presence of nano-titania-supported Preyssler-type heteropolyacid, n-TiO2/H14[NaP5W30O110], as a heterogeneous catalyst. The reactions proceeded smoothly under ultrasound irradiation condition to afford the corresponding products in quantitative yields. The catalyst can be easily recovered and reused for several successive fresh runs with no significant loss of catalytic activity.
In this work, an efficient and straight procedure has been described for one-potthree-componentsynthesis of pyranopyrazole derivatives in the presence of a new cobalt Schiff-base complex immobilized on silica-coated Fe3O4 nanoparticles as a reusable catalyst. This new catalyst was characterized by different techniques, such as Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), field-emission
在这项工作中,已经描述了在固定在二氧化硅包覆的Fe 3 O 4上的新型钴席夫碱复合物存在下,一锅三组分合成吡喃并吡唑衍生物的有效而简单的方法。纳米颗粒作为可重复使用的催化剂。这种新催化剂的特征在于不同的技术,例如傅立叶变换红外(FT-IR),X射线粉末衍射(XRD),场发射扫描电子显微镜(FE-SEM),能量色散X射线光谱(EDX) ),电感耦合等离子体(ICP)和振动样品磁力计(VSM)。通过在室温下以短反应时间,高收率和TON的不同芳族醛,丙二腈和3-甲基-1-苯基-2-吡唑啉-5-酮的三组分缩合反应,对上述催化剂进行了吡喃并吡唑的合成进行了有效的测试。最高可达388。所考虑的催化剂可以重复使用几次,而不会损失其催化活性。最后,
Nano-titania sulfuric acid-promoted synthesis of tetrahydrobenzo[b]pyran and 1,4-dihydropyrano[2,3-c]pyrazole derivatives under ultrasound irradiation
作者:Davood Azarifar、Seyed-Mola Khatami、Mohammad Ali Zolfigol、Razieh Nejat-Yami
DOI:10.1007/s13738-013-0392-4
日期:2014.8
An efficient and convenient procedure has been described for one-pot synthesis of tetrahydrobenzo[b]pyran and 1,4-dihydropyrano[2,3-c]pyrazole derivatives in the presence of nano-titania sulfuric acid (15-nm TSA) as a heterogeneous catalyst. The catalyst is easily prepared from the reaction of nano-titania and chlorosulfonic acid in dichloromethane as solvent. The transmission electron microscopy image of the catalyst showed no detectable changes on the size of the nano-catalyst as a result of chemisorptions of the sulfuric acid. To examine the effect of minimizing the size of TSA particles, the pH analysis of the catalyst with different particle sizes was carried out. The catalyst can be easily recovered and reused for several successive fresh runs without significant loss of activity. Under ultrasound irradiation condition, the reactions proceed smoothly to afford the corresponding products in quantitative yields.