All-Inorganic Networks and Tetramer Based on Tin(II)-Containing Polyoxometalates: Tuning Structural and Spectral Properties with Lone-Pairs

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• 作者：Chongchao Zhao ; Elliot N. Glass ; Bryant Chica ; Djamaladdin G. Musaev ; Jordan M. Sumliner ; R. Brian Dyer ; Tianquan Lian ; Craig L. Hill
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：August 27, 2014
• 年：2014
• 卷：136
• 期：34
• 页码：12085-12091
• 全文大小：443K
• ISSN：1520-5126

文摘

Two MOF-like but all-inorganic polyoxometalate-based networks, [Na₇X₂W₁₈Sn₉Cl₅O₆₈路(H₂O)_m]_n (1, X = Si, m = 35; 2, X = Ge, m = 41), and the molecular tetramer Na₆[{Na(渭-OH₂)(OH₂)₂}₆{Sn₆(B-SbW₉O₃₃)₂}₂]路50H₂O (3) have been prepared and characterized by X-ray diffraction and spectroscopic methods. All three compounds exhibit unique structural features, and networks 1 and 2 incorporate the highest nuclearity of Sn(II)-containing POMs to date. Tetramer 3 comprises bridging Sn(II) ions with [B-SbW₉O₃₃]^{9鈥?/sup> units and exhibits two highly unusual features, a long-range Sb路路路Sb interaction and an intramolecular charge-transfer transition involving donation of the lone-pair electron density on both Sb(III) and Sn(II) to the POM. The electronic structure and excited-state dynamics have been studied by transient spectroscopy, spectroelectrochemistry, DFT calculations, and resonance Raman spectroscopy. The synergistic effect of two types of stereoactive lone-pairs on Sb(III) and Sn(II) is critical for the charge-transfer absorption feature in the visible.}