Synthesis and characterization of β-lactam functionalized superparamagnetic Fe₃O₄@SiO₂ nanoparticles as an approach for improvement of antibacterial activity of β-lactams

Abstract

Preparation of magnetic β-lactam functionalized Fe3O4@SiO2 nanoparticles has a synergic effect to improve the antibacterial activity.

Copper(II) Complex Supported on Fe3O4@SiO2 Coated by Polyvinyl Alcohol as Reusable Nanocatalyst in N‐Arylation of Amines and N(H)‐ Heterocycles and Green Synthesis of 1H‐Tetrazoles

“…Reflections observed at 30.1°, 35.4°, 43.1°, 53.4°, 57.0°, and 62.6° are belong to the (220), (311), (400), (422), (511), and (440) crystallographic planes of the cubic spinel structure of the magnetite (reference JCPDS card no. 19–629) ,. After being coated by SiO 2 , the diffraction intensity of the magnetite phase decreased obviously (Figure b).…”

“…Then, the reaction of TCT with Fe 3 O 4 @SiO 2 -N(OH) 2 NPs (2) is resulted in 3 that its reaction with polyvinyl alcohol (PVA) and then with Cu(OAc) 2 in THF give Fe 3 O 4 @SiO 2 -TCT-PVA-Cu(II) NPs (4). In addition to absorption bands at 3410 and 1612 cm À1 , which are related to physical absorption of OH group (stretching and bending), the occurring characteristic absorption peak at around 570 cm À1 , which is belong to the stretching FeÀO ( Figure 1a), [12] and a strong peak of SiO 2 at 1091 cm À1 , which is allocated to the stretching Si-OÀSi, [38,39] confirm the presence of magnetic core-shell of Fe 3 O 4 @SiO 2 in the structure of all nanoparticles synthesized in Scheme 1 (Figure 1b The presence of peaks at 702 cm À1 (stretching CÀCl), 1444 cm À1 (bending CH 2 ), and 2954 cm À1 (stretching CÀH) clearly show the surface functionalization of core-shell by (3chloropropyl)trimethoxysilane ( Figure 1c). The existent of a peak at 1354 cm À1 (stretching CÀN) and disappearing of CÀCl peak exhibit the successful reaction between 3-(3-Hydroxypropylamino)-propan-1-ol and Fe 3 O 4 @SiO 2 -Cl and confirms the formation of Fe 3 O 4 @SiO 2 -(OH) 2 NPs.…”

“…The crystalline structure of (a) Fe 3 . [38,40] After being coated by SiO 2 , the diffraction intensity of the magnetite phase decreased obviously ( Figure 2b). As shown in Figure 2b and 2c, a wide diffraction of amorphous SiO 2 can be found between 2V values of 108 and 258 which reveals the surface modification of Fe 3 O 4 nanoparticles has not been resulted in the phase change in Fe 3 O 4 @SiO 2 -TCT-PVA-Cu(II) nanoparticles and is only transferred slightly to lower angles because of the synergetic effect of amorphous silica and polymer ( Figure 2c).…”

Green, cost‐effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst

“…In Figure , the relatively strong diffraction peaks at 2 ϴ = 10–90° can be assigned to the (220), (311), (400), (422), (511) and (440) planes, which agreed with the crystallographic planes of magnetite as well and indicates the presence of an Fe 3 O 4 core with highly crystalline cubic spinel structure (reference JCPDS card no. 19–629) …”

“…. [63] The characteristic peaks of Fe 3 O 4 can be detected in the XRD pattern of Fe 3 O 4 @SiO 2 and Fe 3 O 4 @SiO 2 -TCT-PVA-Pd(0) NPs but with slight decrease in intensity (Figure 2b, c), suggesting the successful wrapping of Fe 3 O 4 NPs with SiO 2 and PVA.…”