Double sandwich polyoxometalate and its Fe(III) substituted derivative, [As2Fe5Mo21O82]17– and [As2Fe6Mo20O80(H2O)2]16–.
A double sandwich polyoxometalate and its Fe(III) substituted derivative, [As(2)Fe(5)Mo(21)O(82)](17-) (1) and [As(2)Fe(6)Mo(20)O(80)(H(2)O)(2)](16-) (2), were synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, fluorescent spectroscopy, UV spectra, thermogravimetry-differential scanning calorimetry analyses, electrospray ionization mass spectrometry, and magnetism measurements. The polyoxoanion is composed of a central fragment FeMo(7)O(28) for 1 (Fe(2)Mo(6)O(26)(H(2)O)(2) for 2) and two external AsMo(7)O(27) fragments linked together by two distinct edge-sharing dimeric clusters Fe(2)O(10) to lead to a C(2v) molecular symmetry. The central FeMo(7)O(28) fragment and external AsMo(7)O(27) fragment have a similar structure, and both of them can be viewed as a monocapped hexavacant α-Keggin subunit with a central FeO(4) group or a central AsO(3) group. Both of the polyoxoanions contain a oxo-bridged Fe(III)(5) magnetic core with the angles of Fe-O-Fe in the range of 96.4(4)-125.7(5)°, and magnetism measurements show an overall ferromagnetic interactions among the five-nuclearity cluster Fe(5) with the spin ground state S = 15/2.
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Department of Chemistry, Northwest University, Xìan, 710069, China.
Xiangqian
X
Dong
Yanping
Y
Zhang
Bin
B
Liu
Yanzhong
Y
Zhen
Huaiming
H
Hu
Ganglin
G
Xue
D002152:Calorimetry, Differential Scanning; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017973:Tungsten Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D000099294:Polyoxometalates
D005290:Ferric Compounds; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates