Immobilized different amines on modified magnetic nanoparticles as catalyst for biodiesel production from soybean oil

Fe₃O₄ nanoparticles were modified with tetraethylorthosilicate (TEOS) and (3-chloropropyl)trimethoxysilane (CPTMS) followed by immobilization with different amines such as guanine, piperazine, methylamine, morpholine, aniline, ethylenediamine, 3-aminopropyltriethoxysilane, and melamine, designated as Fe₃O₄@SiO₂@CPTMS@amine (nanocatalyst). The prepared nanocatalysts were characterized by means of FTIR, XRD, VSM, SEM, and TEM. Trans-esterification reactions of soybean oil with methanol were then carried out in the presence of the Fe₃O₄@SiO₂@CPTMS@amine as a nanocatalyst. Optimization of the reaction parameters revealed that the fatty acid methyl esters (FAMEs or biodiesel) is obtained in 6–96% yields by using methanol to oil molar ratio of 36 in the presence of 6% of nanocatalysts containing melamine and guanine, respectively, at 160 °C within 3 h. The stability and reusability of the catalyst as well as the effect of reaction parameters on the FAME yield are described in this paper.     

Synthesis and Antibacterial Activity of Pyranopyrimidinedione Derivatives

Russian Journal of Organic Chemistry - Four pyranopyrimidinedione derivatives were prepared through a one-pot pseudo-three-component acetic acid-catalyzed reaction of 6-amino-1,3-dimethyluracil...     

Synthesis,characterization and immobilization of a novel mononuclear vanadium (V) complex on modified magnetic nanoparticles as catalyst for epoxidation of allyl alcohols

The 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine (tptz) undergoes hydrolysis in the presence of VO(SO₄) in an alkaline solution, affording mainly the bis(2‐pyridyl carbonyl)amid ) VO₂ complex, designated as [VO₂(bpca)]. Single‐crystal X‐ray crystallography revealed that the coordination of V in complex is a distorted square‐pyramid coordinated with three nitrogen of bis(2‐pyridyl carbonyl)amid ) ligand and two binding oxygen atoms. The prepared complex which successfully supported on modified Fe₃O₄ nanoparticles using tetraethylorthosilicate (TEOS) and (3‐aminopropyl)trimethoxysilane(APTMS)was designated as Fe₃O₄@SiO₂@APTMS@[VO₂(bpca)] complex (nanocatalyst). The complex and nanocatalyst were characterized by means of FT‐IR, XRD, VSM, SEM and TEM. The catalytic activity of [VO₂(bpca)] complex and Fe₃O₄@SiO₂@APTMS@complex as catalysts 1 and 2 were evaluated by the epoxidation of geraniol , 3‐methyl‐2‐buten‐1‐ol , trans‐2‐hexen‐1‐ol and 1‐octen‐3‐ol with 70–98% conversions and 95–100% selectivities. Based on the obtained results, the heterogeneity and reusability of the catalyst seems promising. In addition, the in vitro antibacterial activity of [VO₂ (bpca)] complex have also been evaluated and compared to the activities of other vanadium complexes, tptz ligand and two standard antibacterial drugs, Nalidixic acid and Vancomycin.