A new soluble Schiff base polymer with a double azomethine group synthesized by oxidative polycondensation

In this study, the new oligomer Schiff base oligo-N,N -bis (2,4-dihydroxybenzylidene) ethylenediamine (O-DHBEDA), with a double azomethine group, was synthesized by oxidative polycondensation (OP) of N,N -bis (2,4-dihydroxybenzylidene) ethylenediamine (DHBEDA) with NaOCl as an oxidant in an aqueous alkaline medium at 90 • C. About 69.3% DHBEDA was converted to O-DHBEDA. The structures of the products were studied by UV-Vis, FT-IR, 1 H-NMR, 13 C-NMR and elemental analysis. According to gel-permeation chromatography (GPC) analysis of O-DHBEDA, the number-average molecular weight (M n ), weight-average molecular weight (M w ) and PDI values were found to be 5255 g/mol, 9116 g/mol and 1.73, respectively. During the polycondensation reaction, a part of the azomethine (-CH=N-) groups oxidized to aldehyde (CHO) groups (approx. 4%). Oligomer-metal complexes of oligo-N,N -bis (2,4-dihydroxybenzylidene) ethylenediamine (O-DHBEDA) with Co (II) and Mn (II) were synthesized and characterized by FT-IR, UV-Vis, TG-DTA and atomic absorption spectroscopy (AAS). TG/DTA analyses were shown to be stable of O-DHBEDA against thermo-oxidative decomposition. The residue values of DHBEDA, O-DHBEDA, O-DHBEDA-Co and O-DHBEDA-Mn were found to be 0%, 7.1%, 14% and 13.4%, respectively, at 1000 • C.

Section: Structure Of Dhbeda O-dhbeda and O-dhbeda-metal Complexesmentioning

confidence: 89%

Section: Structure Of Dhbeda O-dhbeda and O-dhbeda-metal Complexesmentioning

confidence: 99%

Synthesis, Characterization and Thermal Properties of Oligo-N,N′-bis (2,4-dihydroxybenzylidene) ethylenediamine and Its Cobalt (II) and Manganese (II) Complexes

Demetgül

Karakaplan

Serın

2008

“…The bands at 330-450 nm were attributed to the n-π * transition of the non-bonding electrons present on the nitrogen of the azomethine group in the Schiff base. As being different from monomers, the polymers' absorption region in 450-600 nm can be caused by their long polymer structure systems [24]. In the spectra of the complexes the bands of the azomethine n-π * transition are shifted to lower frequencies, indicating that the azomethine nitrogen atoms are involved in coordination to the metal ions [25].…”

Section: Structures Of the Polymers And Polymer-metal Complexesmentioning

confidence: 99%

Schiff Base Polymers Obtained by Oxidative Polycondensation and Their Co(II), Mn(II) and Ru(III) Complexes: Synthesis, Characterization and Catalytic Activity in Epoxidation of Styrene

Demetgül

Delikanlı

Sarıbıyık

et al. 2012

In this paper, Schiff base monomers having double azomethine groups, N,N -bis(4-hydroxybenzylidene)1, 4-phenylenediamine (M 1 ) and N,N -bis(4-hydroxysalicylidene)1,4-phenylenediamine (M 2 ), were prepared by a common condensation reaction between 4-hydroxybenzaldehyde and 4-hydroxysalicylaldehyde with 1,4-phenylenediamine, respectively. The new Schiff base polymers, poly(N,N -bis(4-hydroxybenzylidene)1,4-phenylenediamine) (P 1 ) and poly(N,N -bis(4-hydroxysalicylidene)1,4-phenylenediamine) (P 2 ) were synthesized from the oxidative polycondensation of monomers with NaOCl in an aqueous alkaline medium. The characterization of synthesized monomers and polymers was carried out by FT-IR, UV-Vis, 1 H-NM, 13 C-NMR and elemental analysis. The new polymer-metal complexes were prepared by using polymers and Co(II), Mn(II) and Ru(III) metal salts. Thermal properties of the compounds were studied by TG-DTA techniques. In addition, the catalytic properties of the polymers and their metal complexes were investigated in epoxidation reactions of styrene. The results of the catalysis studies were monitored by GC-MS.

“…Also, after the demetallation step the band in the 600 cm −1 range disappeared. The vibrational mode (both stretching and bending) due to the C-N bond appears at 1328 and 1124 cm −1 in the metal complex of thiourea compounds [33][34][35][36][37][38][39].…”

Section: Synthesismentioning

confidence: 99%

Synthesis, Characterization and Catalytic Investigation of Novel Polymeric Thiourea

Sarıbıyık

Serın

2011

Self Cite

In this study, in order to obtain polymeric thiourea compounds which have unsolubulity properties and higher metal content, new reaction pathways based on the use of the template effect were investigated. For this purpose, the reactions between different diamines, such as ethylendiamine, ortho (o-) and para (p-) phenylenediamine, and carbon disulfide (CS 2 ) were investigated and optimized by using the template effect of Ni(II). Catalytic activity of the polymeric structure on oxidation of styrene was also investigated in terms of different parameters such as heat (25 and 80 • C), time (4 and 8 h), oxidant hydrogen peroxide (H 2 O 2 ), tert-butyl hydroperoxide (TBHP), di-tert-butyl peroxide (DtBP) and solvent (acetonitrile and benzene). The products have been characterized on the basis of analytical and spectral method, Fourier transform infrared spectroscopy, 1 H-and 13 C-nuclear magnetic resonance, gel-permeation chromatography, elemental analysis, thermogravimetric analysis, atomic adsorbtion spectrometry, gas chromatography and gas chromatography mass spectrometry.