A {Nb6 P2 W12 }-Based Hexameric Manganese Cluster with Single-Molecule Magnet Properties.
By deliberately using a metastable polyanion [(NbO2 )6 P2 W12 O56 ](12-) (1), which was formed in situ, we have discovered the unprecedented hexameric cluster {Mn15 (Nb6 P2 W12 O62 )6 } (2), in which the six polyanions [Nb6 P2 W12 O61 ](10-) are alternately connected by four intriguing trinuclear {Mn(III) 3 } moieties and four {Mn(II) } linkers. This discovery is the first in which the phosphoniobotungstate has been made accessible by using transition-metal ions; furthermore, polyanion 2 represents the largest niobotungstate cluster reported to date. Analysis by means of electrospray ionization mass spectrometry (ESI-MS) provides insight into the self-assembly process, and the peaks observed relate to the different charge states of the parent cluster, thus confirming the stability of 2. In addition, magnetic-susceptibility measurements reveal that each {Mn(III) 3 } subunit is a separate single-molecule magnet (SMM). This discovery results from the exploration of the reverse effect of metastable polyanion 1 possessing high reactivity, thereby turning a disadvantage into an advantage. This finding could define a new synthetic strategy for the design and synthesis of magnetic polyoxometalate (POM) clusters.
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (P.R. China).
Dongdi
D
Zhang
State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (P.R. China).
Fan
F
Cao
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (P.R. China).
Pengtao
P
Ma
Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 361005 (P.R. China).
Chao
C
Zhang
State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (P.R. China).
You
Y
Song
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (P.R. China).
Zhijie
Z
Liang
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (P.R. China).
Xiaojing
X
Hu
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (P.R. China). niujy@henu.edu.cn.
Jingping
J
Wang
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (P.R. China). wjp@henu.edu.cn.
Jingyang
J
Niu
heterometallic cages; magnetic properties; molecular magnetism; polyoxometalates; transition metals