Self-Assembly, Structures, and Solution Dynamics of Emissive Silver Metallacycles and Helices

Reactions of 9,10-bis(diphenylphosphino)anthracene (PAnP) and AgX (X = OTf^-, ClO₄^-, PF₆^-, and BF₄^-) led to luminescent Ag−PAnP complexes with rich structural diversity. Helical polymers [Ag(μ-PAnP)(CH₃CN)X]_n (X = OTf^-, ClO₄^-, and PF₆^-) and discrete binuclear [Ag₂(μ-PAnP)₂(CH₃CN)₄](PF₆)₂, trinuclear [Ag₃(μ-PAnP)₃⊃BF₄](BF₄)₂, and tetranuclear [Ag₄(μ-PAnP)₄⊃(ClO₄)₂](ClO₄)₂ metallacycles were isolated from different solvents. The tri- and tetranuclear metallacycles exhibited novel puckered-ring and saddlelike structures. Variable-temperature (VT) ³¹P{¹H}-NMR spectroscopy of the complexes was solvent dependent. The dynamics in CD₃CN involve two species, but the exchange processes in CD₂Cl₂ are more complicated. A ring-opening polymerization was proposed for the exchange mechanism in CD₃CN.