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

Abstract

Two MOF-like but all-inorganic polyoxometalate-based networks, [Na7X2W18Sn9Cl5O68·(H2O)m]n (1, X = Si, m = 35; 2, X = Ge, m = 41), and the molecular tetramer Na6[{Na(μ-OH2)(OH2)2}6{Sn6(B-SbW9O33)2}2]·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-) units and exhibits two highly unusual features, a long-range Sb···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.

Self-Assembly and Ionic-Lattice-like Secondary Structure of a Flexible Linear Polymer of Highly Charged Inorganic Building Blocks

“…Soluble components are routinely utilized as structural building units (SBUs) for the self-assembly of functional materials. − In this context, metal oxide cluster anions, or polyoxometalates (POMs), are used as SBUs for assemblies featuring the extensive and readily tunable electronic and catalytic properties of the POM building blocks themselves. − The challenge in these efforts generally is to develop methods based on rational design principles, which in turn requires detailed understanding of how interactions in solution lead to specific hierarchical organizations …”

Macrocyclic Inorganic Tin‐Containing Oxo Clusters: Heterometallic Strategy for Configuration and Catalytic Activity Modulation

“…[23][24][25] Therefore, the construction of non-organotin complexes is highly appealing. Although a few pyrazole stabilized non-alkyl tin-oxo clusters without SnÀ C bonds were recently prepared by us and several lacunary polyoxometalates stabilized inorganic SnÀ O moieties were known, [26][27][28][29][30][31] the preparation of pure inorganic tin-oxo clusters is still very challenging.…”

“…As indicated by Figures 3a and 3b, although the adjacent Sn 8 (SO 4 ) 16 and Ti 6 (SO 4 ) 9 macrocycles are both parallel, they stack in significantly different behaviors, possibly caused by the two encapsulated Sn 2 + ions with lone electron paris to act as structure-directing sites. [27,29] In TOC-34, two Sn 8 (SO 4 ) 16 macrocycles are firstly combined by hydrogen bonding interactions between the 17 th SO 4 in their central Sn 2 (SO 4 ) moieties. The dimerized Sn 8 (SO 4 ) 16 macrocycle pair is then surrounded by 18 EMIm cations to reach a charge balance for the whole structure.…”

Organic Molecule Modified Phosphotungstate with Helical Structure for Electrochemical Detection of Dopamine

“…[26,27] To maximize the benefit of HPAs, the design and synthesis of HPA-based crystalline materials have been developed as an efficient strategy that can realize a good dispersal of HPAs at the molecular level and can expose more accessible active sites. Based on extensive studies on crystalline HPA-based compounds, three different types (metal ions, [28][29][30] organic molecules [31,32] and metal-organic hybrids [33][34][35] for modify HPAs) can be available. As we all know, many biological molecules, such as proteins, nucleic acid, are the use of all kinds of intermolecular or intramolecular non-covalent bonds to achieve a high degree of orderly and advanced structure.…”