Synthesis and Characterization of Cobalt(II) Salicylaldimine Complex Supported on Silica Covered Magnetite

Cobalt Schiff base complex is widely used in many reactions such as reduction process, carbonylation of alcohol and oxidation of alkenes. Generally, this catalyst is in the powder form. It is difficult to separate the catalyst from the reaction mixture due to the small particles size of the catalyst. One way to easily separate the catalyst is by applying external magnetic field. However these catalysts would have to possess magnetic properties for this method to work on. One of the strategies to solve this problem is by adding magnetic material into the catalysts. Magnetite is a common magnetic material used as a support material which can be synthesized by the co-precipitation method of Fe2+ andFe3+. Normally, magnetite is covered by silica in order to stabilize and reduce its toxicity. This can be done by using the sol-gel approach. Silica coated magnetite is widely used as a support material because of its high surface area and easy catalyst separation after the reaction simply by applying an external magnetic field. In this research, cobalt Schiff base complex/silica@magnetite was synthesized from the condensation of cobalt (II) salicylaldehyde with 3-aminopropyltrimethoxy silane on the surface of silica@magnetite. The catalysts were characterized using Fourier transform infrared spectrometer, scanning electron microscopy and diffuse reflectance ultra-violet visible spectrometry.

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Synthesis and Magnetic Properties of Poly(Schiff Base) Complex Containing 4,7-Disubstituted-1,10-Phenanthroline

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.1043 ◽

2011 ◽

Vol 399-401 ◽

pp. 1043-1047

Author(s):

Ren Hua Zheng ◽

Hua Jiang Jiang ◽

Qun Shen ◽

Hai Chang Guo

Keyword(s):

Magnetic Field ◽

Magnetic Properties ◽

Schiff Base ◽

Field Strength ◽

Magnetic Field Strength ◽

Elemental Analysis ◽

Schiff Base Complex ◽

Polymeric Complex ◽

Base Complex ◽

H Nmr

A novel poly(Schiff base) containing 4,7-disubstituted-1,10-phenanthroline (BAPcBDA) was synthesized by the polycondensation of 4,7-Bis(4-aminophenoxy)-l, l0-phenanthroline (BAP) with 4,4'-Biphenyldicarboxaldehyde (BDA). The polymeric complex was first prepared by the reaction of polymer (BAPcBDA) with NiSO4. The structures of the monomer and polymer were characterized by IR,1H-NMR, and elemental analysis. The magnetic behaviors of the complex were measured as a function of magnetic field strength (0-50 kOe) at 5 K and as a function of temperature (5-300 K) at a magnetic field strength of 30 KOe. The results show that BAPcBDA-Ni2+exhibited the features of an antiferromagnet.

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Synthesis of Bis (Benzoyl Acetone Ethylene Diimine) Schiff Base Complex of Nickel (II) Supported on Magnetite Silica Nano-Particles (Fe3O4@Sio2/Schiff-Base Of Ni (II)) and Using it as an Efficient Catalyst for Green Synthesis of 1-Amidoalkyl-2-Naphthol.

10.21203/rs.3.rs-700894/v1 ◽

2021 ◽

Author(s):

Moslem Setoodehkhah ◽

Amin Mazraati ◽

Mohsen Moradian

Keyword(s):

Schiff Base ◽

Condensation Reaction ◽

Schiff Base Complex ◽

Nano Particles ◽

Precipitation Method ◽

Efficient Catalyst ◽

Nano Structure ◽

Base Complex ◽

Nano Catalyst ◽

Ft Ir

Abstract In this research, magnetite nano-particles as the core are fabricated by co-precipitation method from Fe(II) and Fe(III) chloride salts and then the surfaces of the nano-particles are modified to improve their performance. These modifications include the coating of silica and then the second layer by 3-amino propyl triethoxy silane (APTES) which causes the functionalization of magnetite nanoparticles with –NH2 groups. In the next step, an aliphatic tetra-dentate N2O2 Schiff base was synthesized by condensation reaction between benzoyl acetone and ethylenediamine. Then this Schiff base is immobilized on the magnetite silica surfaces. This immobilized Schiff base was converted to the Ni (II) Schiff base complex by the reaction with Ni(II) acetate tetrahydrate. This Ni (II) Schiff base complex is immobilized on magnetite silica and shown as Fe3O4@SiO2/Schiff base of Ni (II). This cor-shell nano-structure is fully characterized by techniques such as FT-IR, VSM, XRD, FE-SEM, EDX, TGA-DTA, AAS, BET, and BJH. In the last step, this nano-catalyst is used as an efficient catalyst for the solvent-free synthesis of amido alkyl naphthols by the condensation reaction between an aldehyde, 2-naphthol, and an amide. The reaction was monitored by TLC. At the end of the reaction, the nano-catalyst was removed easily from the reaction mixture by an external magnet. The products of amido alkyl naphthols were identified by FT-IR and 1HNMR techniques. Finally, the percentage yield of the reaction is calculated by measuring the mass of 1-amidoalkyl-2-naphthol synthesized in the presence of the catalyst.

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