Assembling silver(i) coordination polymers of an NS4-macrocycle via an endo/exocyclic coordination mode

Abstract

Networking of molecular hosts via non-covalent interactions has become one of the central topics in crystal engineering. We herein report the self-assembly of silver(i) coordination polymers with an NS4-macrocycle (L) whose connectivity patterns depend on anion types. First, a one-pot reaction of L with AgPF6 yielded an endo/exocyclic one-dimensional (1D) coordination polymer {[Ag3L2](PF6)3·2CH2Cl2}n (1) in which two silver(i) atoms (endoAg)2 are sandwiched by two L ligands to form an L(endoAg)2L unit. Further, the disilver(i) sandwich units are linked by one exocyclic silver(i) atom (exoAg), giving rise to a polymeric loop chain array of 1 without anion coordination. When L was reacted with AgCF3SO3 and AgCF3CO2, again, endo/exocyclic 1D coordination polymers {[Ag4L2(CF3SO3)2](CF3SO3)2·CH2Cl2}n (2) and {[Ag4L2(CF3CO2)2](CF3CO2)2·4CH3OH}n (3) with a similar connectivity pattern were obtained, respectively. In both 2 and 3, one endoAg atom and one exoAg atom link three L ligands to form a double-stranded array with one anion coordinated to the exoAg atom. In the anion exchange experiments, the formation of 2 (CF3SO3− form) is relatively favourable over 1 (PF6− form) or 3 (CF3CO2− form) mainly due to the anion access-friendly conformation and moderate binding affinity of CF3SO3− which can easily gain entry. © 2023 The Royal Society of Chemistry.