New Polythiophene(keto-amine)s Based on Cyclopentanone Moiety, Synthesis, Characterization and Selective Metal Ions Uptake
Khalid A. Alamry, Mahmoud A. Hussein*, Hadi M. Marwani, Abdullah M. Asiri, Mona A. Abdel- Rahman
1 Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah, Saudi Arabia 21589
New category of polythiophene (keto-amine)s (PTKA) 3a-e containing thiophene-arylidene-thiophene tri blocks moieties in polymers backbones was synthesized by the interaction of the monomer 2 with different aromatic, cyclic and aliphatic diamines. The polymerization had occurred using polycondensation process in dry benzene as solvent. A new monomer namely, 2,5-bis[4-choloroacetyl(thiophen-2-ylmethylene)]cyclopentanone 2 was firstly synthesized using the normal condition of Friedel-Crafts reaction by the reaction of 2,5-bis(thiophen-2-ylmethylene)cyclopentanone 1 with chloroacetyl chloride in the presence of aluminum chloride anhydrous. The structure of the new monomer as well as polymers was confirmed by elemental and spectral analyses. Furthermore, solubility, viscometry, SEM and thermal characteristics for the new polymers were tested. All the polymers were freely soluble in formic acid as good example for polar protic solvents. PDTmax and FDT for all the polymers were detected and were in the range 434 – 467 ºC and 487 – 533 ºC respectively. On the other hand, the analytical competition of newly synthesized PTKA polymers 3a and 3c was also evaluated for a selective extraction of metal ions prior to their determination by inductively coupled plasma-optical emission spectrometry. The selectivity of PTKA 3a and PTKA 3c towards different metal ions, including Cd (II), Co(II), Cu(II), Cr(III), Fe(III), Ni(II) and Zn(II), was studied. Results of the selectivity study demonstrated that 3a and 3c polymers was the most selective towards Cr (III) and Co(II). Adsorption capacity of 3a for Cr(III) was improved by 38.37% in comparison to that of 3c for Co(II) after only 1 h contact time. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on homogeneous adsorbent surfaces of both PTKA 3a and PTKA 3c.
Keywords: Polythiophene(keto-amine)s; Thiophene; Synthesis; Characterization; Adsorption capacity; Co(II); Fe(III).
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