Two MOF-like but all-inorganic polyoxometalate-based networks, [Na7X2W18Sn9Cl5O68 center dot(H2O)(m)](n) (1, X = Si, m = 35; 2, X = Ge, m = 41), and the molecular tetramer Na-6[{Na(mu-OH2)(OH2)(2)}(6){Sn-6(B-SbW9O33)(2)}(2)]center dot 50H(2)O (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 center dot center dot center dot 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.