Three rare-earth incorporating 6-peroxotantalo-4-selenates and catalytic activities for imidation reaction.
Weixin DuYufeng LiuJunjun SunHaiying WangGuoping YangDongdi ZhangPublished in: Dalton transactions (Cambridge, England : 2003) (2022)
Functionalization with belt lanthanide groups allows for the crystallization and structural characterization of homometallic selenotantalates, CsK[Ln(H 2 O) 6 Se 4 (TaO 2 ) 6 (OH) 3 O 18 ]· n H 2 O (Ln = Eu/Gd, n = 14 (STD-Eu, STD-Gd) and Ln = Lu, n = 12 (STD-Lu)). The basket-shaped {Se 4 (TaO 2 ) 6 } archetype is assembled in a simple one-pot reaction of Na 2 SeO 3 and K 8 [Ta 6 O 19 ]·17H 2 O in acidic aqueous medium (pH 2) and in the presence of hydrogen peroxide. This unit has been proven to be an effective precursor for the preparation of a range of new POMs containing the {Se 4 (TaO 2 ) 6 } unit. The lanthanide derivatives STD-Eu, STD-Gd and STD-Lu have been fully characterized with single-crystal X-ray diffraction, IR spectroscopy, TG analysis and PXRD in the solid state. The photoluminescence and lifetime decay behaviours of STD-Eu have been studied at room temperature, and the photoluminescence spectrum displays the characteristic emission of the Eu 3+ cation. In addition, the catalytic activities of STD-Eu, STD-Gd and STD-Lu on the reaction of phthalic anhydride with phenylamines have been investigated. STD-Eu shows good catalytic activities for imidation reactions.