Construction of Ag(I)–Ln(III) Heterometallic Coordination Polymers Based on Binuclear Ag2(DSPT)2 (H2DSPT = 4′-(2,4-Disulfophenyl)-2,2′:6′2″-terpyridine) Rings and Ln(III) Dimeric Molecular Building Blocks

Four new 4d–4f heterometallic coordination polymers, namely, {[LnAg(DSPT)(mBDC)(H2O)2]·H2O}n [Ln = Sm, (1); Ln = Er, (2); H2DSPT = 4′-(2,4-disulfophenyl)-2,2′:6′2″-terpyridine); H2mBDC = 1,3-benzenedicarboxylic acid], {[CeAg(DPST)(mBDC)(H2O)2]·H2O}n (3), and {[TbAg3(DPST)2(INC)2(H2O)]}n [HINC = isonicotinic acid, (4)], have been successfully synthesized under hydrothermal conditions and structurally characterized. The four components, including Ln(III) ions, Ag(I) ions, and the two organic ligands, are successfully incorporated into a single framework. They are all heterometallic complexes based on two kinds of molecular building blocks (MBBs), the Ag2(DSPT)2 ring (MBB I) and Ln2(COO)2 dimeric unit (MBB II). Complexes 1 and 2 are isostructural and exhibit a 2D network constructed by MBBs I and II, and further linked by Ag···π interactions to a 3D supramolecular framework. Complexes 3 and 4 are 3D frameworks with sqc-21 and sqc-495 topologies by considering MBB I and II as nodes and coordination bonds/Ag··...