Divergent Structural Transformations in 3D Ag(I) Porous Coordination Polymers Induced by Solvent and Anion Exchanges

Two series of ten 3D porous coordination polymers (PCPs), [Ag(L434)](BF4)(DMF)2 (1·BF4·DMF), [Ag(L434)](BF4)(CH3CN)2 (1·BF4·CH3CN), [Ag(L434)](BF4)(DMA)(CH3OH) (1·BF4·DMA/CH3OH), [Ag(L434)](ClO4)(DMF)2 (1·ClO4·DMF), [Ag(L434)](CF3SO3)(DMF) (1·CF3SO3·DMF), [Ag(L434)](ClO4)(CH3CN)2 (1·ClO4·CH3CN), [Ag(L434)](PF6)(CH3CN)2 (1·PF6·CH3CN), [Ag(L434)](CH3SO3)(DMA) (1·CH3SO3·DMA), [Ag(L434)](CF3SO3)(DMA) (1·CF3SO3·DMA), and [Ag2(L434)2](BF4)2(CH3OH)2 (2·BF4·CH3OH), have been prepared via assembling 3,5-bis(4-pyridyl)-4-(3-pyridyl)-1,2,4-triazole (L434) with Ag(I) salts in different solvent media. All these PCPs possess 3D porous cationic frameworks, exhibiting irl topology for 2·BF4·CH3OH and sra topology for others (1·anion·solvent) with the same point symbol of (42.63.8). Solvent-induced structural transformations between the topo-isomeric 1·BF4·solvent and 2·BF4·CH3OH show drastic deformations of the 3D host frameworks and concomitant solvent exchanges. Three cycles of anion-induced structural conversions involving 1·anion·DMF, 1·anion·CH3CN, and 1·anion·DMA isoreticular structures are also observed, in which the mother frameworks are almost unchanged during the anion exchanges. These two types of structural transformations occur upon different external stimuli (solvent and anion), which are accompanied by significant changes in the shape of channels and the volume of voids.