Organic-Inorganic Two-Dimensional Hybrid Networks Constructed from Pyridine-4-Carboxylate-Decorated Organotin-Lanthanide Heterometallic Antimotungstates.

Six organic-inorganic hybrid pyridine-4-carboxylate-decorated organotin (OT)-lanthanide (Ln) heterometallic antimotungstates [Ln(H2O)6(pca)]H[Sn(CH3)2(H2O)]3[B-β-SbW9O33]·12H2O [Ln = La3+ (1), Ce3+ (2), Pr3+ (3), Nd3+ (4), Sm3+ (5), Eu3+ (6); Hpca = isonicotinic acid] have been prepared with the help of the structure-directing effect of the trivacant [B-α-SbW9O33]9- segment toward [(CH3)2Sn]2+ and Ln3+ ions in an acidic water medium. The prominent architecture characteristic is that their structural units consist of a trivacant [B-β-SbW9O33]9- segment stabilized by three [Sn(CH3)2(H2O)]2+ groups and a [Ln(H2O)6(pca)]2+ cation, which are interconnected to propagate an intriguing two-dimensional (2D) network. For all we know, 1-6 stand for the first 2D OT-Ln heterometallic polyoxometalates. Furthermore, luminescence performances of solid-state 3-6 were deeply surveyed at ambient temperature. Energy migration from [B-β-SbW9O33]9- and pca- to Sm3+ centers in 5 was also studied. Comparative studies demonstrate that the contribution of [B-β-SbW9O33]9- sensitizing the emission of Sm3+ is prominently larger than that of pca- sensitizing the emission of Sm3+ in the emission process of 5. Most interestingly, 6 as a fluorescence probe exhibits high selectability and sensitivity for recognizing Zn2+ and Cu2+ in water.