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···O interactions as linkers. Complexes 1–4 represent rare examples of 4d–4f coordination polymers containing two kinds of organic ligands. Moreover, thermal gravimetric analysis and luminescence properties studies of selected complexes were also investigated.