Synthesis and Structural Characterization of ... - Jacobs University

Chapter 3
Published Results
Na 8 Eu 2 [Eu 2 (H 2 O) 10 W 28 O 93 (OH) 2 ]·47H 2 O (NaEu-12)
10.00 g of Na 2 WO 4·2H 2 O (30.30 mmol) were dissolved in 20 mL H 2 O followed by dropwise
addition of 3 mL of concentrated HCl (local formation and redissolution of hydrated tungsten
oxide was detected). This was immediately followed by the dropwise addition of 0.81 g
EuCl 3·6H 2 O (2.20 mmol) dissolved in 5 mL H 2 O and the pH was adjusted to 3.2 with 6M
HCl. The mixture was vigorously stirred at room temperature for 1 hour. The white
precipitate formed was filtered off and the filtrate was kept in an open vial for crystallization.
Colorless crystals were obtained after several days, which were filtered off and air dried (yield
3.4 g, 41 %). IR data for NaEu-12: 946(m), 881(sh), 833(s), 801(s), 756(sh), 632(m), 595(m),
473(w), 458(w), 419(w) cm -1 (see Figure 3.11). Anal. Calcd (%) for NaEu-2: Na, 2.2; W,
60.6; Eu, 7.2. Found (%): Na, 1.3; W, 58.4; Eu, 7.4.
Na 14 [Ln 2 (H 2 O) 10 W 28 O 93 (OH) 2 ]·xH 2 O (Ln = La, Ce, Pr, Nd and Gd)
The same procedure as for Na-11 was followed, but using the respective lanthanide chloride
salt instead of SmCl 3·6H 2 O.
Figure 3.11. IR spectra of Na-11 (blue curve) and NaEu-12 (red curve) measured on KBr
pellets.
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