روشن خوشنوازی

The title complexes were synthesized at room temperature by the reaction of A--GeW9O10 34 with MCl3 (M¼Y3þ, Sm3þ, and Yb3þ) in 0.1 mol L1 sodium carbonate solution and characterized by elemental analysis, FT-IR, UV, 13C- and 183W-NMR spectroscopies, and thermogravimetric analysis (TGA). Two-line 183W-NMR spectrum with 2 : 1 intensity ratio confirms that [(A--GeW9O34)2(MOH2)3CO3]13 contains an anion of D3h symmetry. The difference of the two chemical shifts D¼30.56 affirms the presence of A--GeW9O10 34 . The chemical shift of the single-line 13C-NMR spectrum of [(A--GeW9O34)2 (MOH2)3CO3]13 and frequencies of stretching vibrations of all three complexes affirm the presence of coordinated carbonate. TGA shows that the complexes are thermally stable up to 430C.