|
Z. Naturforsch. 2012,
67b, 495 – 498
doi:10.5560/ZNB.2012-0077
Synthesis and Structural Characterization of a Tetra-Cobalt(II)-substituted Sandwich-type Tungstophosphate, (1,3-H2dap)2H4[Co4(1,3-Hdap)2(α-B-PW9O34)2]·3H2O
1 College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475001, P. R. China
2 Henan Quality Polytechnic, Pingdingshan 467000, P. R. China
Reprint requests to Zi Liang Wang. E-mail:
zlwang@henu.edu.cn
Received March 15, 2012 / published online May 31, 2012
A sandwich-type tungstophosphate, (1,3-H2dap)2H4[Co4(1,3-Hdap)2(α-B-PW9O34)2]·3H2O (1,3-dap = 1,3-diaminopropane), was hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental and thermo-gravimetric analysis, and IR and UV spectroscopy. The compound presents a classical tetra-transition metal-substituted sandwich framework, [Co4(1,3-Hdap)2(α-B-PW9O34)2]8−, which contains two lacunary α-B-[PW9O34]9− Keggin units linked by a rhomb-like
Co4O14(1,3-dap)2 cluster lying across an inversion center. The Co2+ ions are coordinated by a mono-protonated dap ligand. Isolatedly protonated 1,3-dap units act as counter-ions interacting with the [PW9O34]9− polyanions via hydrogen bonds forming a three-dimensional framework.
Key words: Polyoxometalate, Crystal Structure, Tungstophosphate, Sandwich, Keggin