| مستخلص: |
[Display omitted] Four polyoxoniobate-based compounds, namely [Cu(en) 2 ] 4 [Cu(en) 2 (H 2 O)][VNb 12 V 4 O 44 ]·2.25H 2 O·3OH– (1), [Cu(en) 2 ] 4 [ Cu (en) 2 (H 2 O)] 3 [Cu(en) 2 (H 2 O) 2 ] 3 {[SiNb 12 Sb 2 O 40 ] 2 }·25H 2 O (2), [Cu(en) 2 ] 2 [ Cu (en) 2 (H 2 O) 2 ] 4 [SiNb 12 V 2 O 42 ]·7H 2 O (3), and [Cu(en) 2 ] 3 {[Cu(en) 2 ][H 2 V 4 Nb 6 O 30 ]}·12H 2 O (4) have been successfully synthesized and characterized by using FT-IR, XRD, and single crystal X-ray diffraction analyses, etc. Out of the four compounds, compound 1 is based on a rare four V capped polyoxoniobate cluster [VNb 12 V 4 O 44 ]7−, [Cu(en) 2 ]2+, and [Cu(en) 2 (H 2 O)]2+ complexes, forming a 1-D chain structure with Cu complexes as bridges. Compound 2 contains a Keggin polyoxoniobate with double Sb caps, and forming a network structure based on Sb capped polyoxoniobates and copper complexes with two different large parallelogram channels. Compounds 3 and 4 have been reported previously by Wang et al[1] and Hu et al[2], respectively. In this work, we not only reported the syntheses, structures and characterizations of these compounds, but also we further investigated the catalytic properties of these four compounds for styrene epoxidation. [ABSTRACT FROM AUTHOR] |
