[Ag(Cyclam)(MeCN)2]2+, a stable Ag(II) complex for photothermal conversion

Two distinct compounds containing the identical new Ag(II) complex cation ([Ag(cyclam)(MeCN)₂] 2+ ) (paired with PF₆ − and OTf − counteranions, respectively) were prepared via reaction of the macrocyclic ligand cyclam (1,4,8,11-tetraazacyclotetradecane) with non-explosive Ag(I) salts (AgPF₆, AgOTf) under ambient room-temperature conditions, with isolated yields of 33% and 31%. Single-crystal X-ray diffraction, electron paramagnetic resonance (EPR, g-tensor = 2.04 in solid state, 2.03 in low-temperature solution), X-ray photoelectron spectroscopy, and mass spectrometry confirmed the formation and stabilization of the Ag(II) center in both compounds. The two compounds exhibit high stability in solid and solution phases and favorable photothermal conversion performance, achieving conversion efficiencies of 50% ([Ag(Cyclam)(MeCN) 2 ](PF 6 ) 2 ) and 74% ([Ag(Cyclam)(MeCN) 2 ](OTf) 2 ).