Multinuclear coordination polymers based on Ag⋯Ag interaction: syntheses, structures, and luminescence properties

A series of coordination polymers based on Ag⋯Ag interactions, namely, [Ag2(hpyb)0.5(L1)0.5(NO3)]·H2O (1), [Ag4(hpyb)(HL2)(NO3)2]·2H2O (2), [Ag3(hpyb)0.5(L3)(NO3)] (3), [Ag6(hpyb)(L4)2(NO3)]·NO3·2H2O (4), [Ag5(hpyb)0.5(L5)2(NO3)]·H2O (5), {Ag4(hpyb)[L6(CH3)2]2} (6), {Ag6(hpyb)(HL7)2[L7(CH3)]} (7) and [Ag3(hpyb)0.5(HL8)]·H2O (8) (H2L1 = p-phthalic acid, H3L2 = 1,2,3-benzenetricarboxylic acid, H2L3 = cis-2-butenedioic acid, H2L4 = 2,3-pyridinedicarboxylic acid, H2L5 = m-phthalic acid, H4L6 = 1,2,4,5-benzenetetracarboxylic acid, H3L7 = 1,2,4-benzenetricarboxylic acid and H4L8 = 4,4′-oxydiphthalic acid) has been synthesized. For compounds 1–4, the polycarboxylate anions bridge multinuclear Ag(I) units to form 1D chains, respectively. The chains are extended by π–π interactions into a 2D supramolecular layer for compound 3 and 3D supramolecular architectures for compounds 1, 2 and 4. Compound 5 displays a 3D (4,8)-connected (34·42)(34·412·58·64)2 framework. Compounds 6–8 exhibit 2D layers, where the layers of 6 and 8 are further linked by π–π interactions to yield 3D supramolecular architectures. In the solid state, compounds 1–8 exhibit strong fluorescence emission bands at room temperature.