Do perfluoroarene⋯arene and C–H⋯F interactions make a difference to the structures of 4,2′:6′,4′′-terpyridine-based coordination polymers?

The consequences for the structures of coordination polymers of introducing fluoro substituents into the terminal phenyl domain of 4′-(biphenyl-4-yl)-4,2′:6′,4′′-terpyridine (1) have been investigated. Reaction between Cu(OAc)2·H2O and 4′-(2′,3′,4′,5′,6′-pentafluorobiphenyl-4-yl)-4,2′:6′,4′′-terpyridine (2) yields the one-dimensional coordination polymer [Cu2(μ-OAc)4(2)]n which contains paddle-wheel {Cu2(OAc)4} nodes bridged by ligands 2. The compound is isostructural with [Cu2(μ-OAc)4(1)]n. When Cu(OAc)2·H2O reacts with a 1 : 1 mixture of 1 and 2, [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n co-crystallize with 1 and 2 disordered over one ligand site; the one-dimensional coordination polymer is isostructural with each of [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n indicating that replacing H by F substituents in the peripheral arene ring has no effect on the overall solid-state structure: tpy⋯tpy π-stacking is preserved, arene⋯arene πH⋯πH interactions are replaced by perfluoroarene⋯arene πF⋯πH interactions, and H⋯H contacts are replaced by H⋯F interactions. In stark contrast to the latter observations, the reaction of Zn(OAc)2·2H2O with perfluoro derivative 2 yields [Zn5(OAc)10(2)4·11H2O]n as the dominant one-dimensional polymer; minor amounts of the anticipated polymer [Zn2(μ-OAc)4(2)]n are also formed. The solid-state structure of [Zn5(OAc)10(2)4·11H2O]n consists of quadruple-stranded polymer chains assembled from {Zn5(2)4} subchains interconnected by {Zn5(OAc)10} units. Within each chain, πF⋯πF and πH⋯πH stacking interactions are dominant, while the observed assembly of chains into sheets and π-stacking between arene units in adjacent sheets mimic the dominant interactions in the single-stranded chains observed in [Zn2(μ-OAc)4(1)]n, [Zn2(μ-OAc)4(2)]n, [Cu2(μ-OAc)4(1)]n, [Cu2(μ-OAc)4(2)]n and [Cu2(μ-OAc)4(1)]n·[Cu2(μ-OAc)4(2)]n.