N,N’-Bis(salicylidene)ethylenediamine was purchased from Merck (Kenilworth, NJ, USA). Its selected properties are presented in Table 1 .
The standard solutions of metal ions (Ni(II), Cu(II), and Zn(II)) were purchased from Sigma Aldrich (Poznan, Poland), while the aqueous solutions of metal ions (Ni(NO3)2, Cu(NO3)2, and Zn(NO3)2) were made from their analytical reagent grade salts (Avantor, Gliwice, Poland) in double-distilled water. The concentration of these solutions was standardized using the atomic absorption spectrometry method. The solution of analytical reagent grade nitric acid (Avantor, Gliwice, Poland) was standardized against anhydrous sodium carbonate. Ammonia was obtained from Avantor (Gliwice, Poland). Methanol, chloroform, and tetrahydrofuran (analytical reagent grade, Avantor, Gliwice, Poland) were used without further purification. Polyvinyl chloride (PVC) with an average molecular weight of 72,000 was obtained from ANWIL (Wloclawek, Poland). Bis(2-ethylhexyl)adipate (DAO) was purchased from Sigma-Aldrich (Poznan, Poland).
The standard solutions of metal ions (Ni(II), Cu(II), and Zn(II)) were purchased from Sigma Aldrich (Poznan, Poland), while the aqueous solutions of metal ions (Ni(NO3)2, Cu(NO3)2, and Zn(NO3)2) were made from their analytical reagent grade salts (Avantor, Gliwice, Poland) in double-distilled water. The concentration of these solutions was standardized using the atomic absorption spectrometry method. The solution of analytical reagent grade nitric acid (Avantor, Gliwice, Poland) was standardized against anhydrous sodium carbonate. Ammonia was obtained from Avantor (Gliwice, Poland). Methanol, chloroform, and tetrahydrofuran (analytical reagent grade, Avantor, Gliwice, Poland) were used without further purification. Polyvinyl chloride (PVC) with an average molecular weight of 72,000 was obtained from ANWIL (Wloclawek, Poland). Bis(2-ethylhexyl)adipate (DAO) was purchased from Sigma-Aldrich (Poznan, Poland).