Facile routes to manganese(II) triflate complexes

Manganese(II) chloride reacts with trimethylsilyl triflate (TMS(OTf) where OTf = − OSO2CF3) in a 1:1 mixture of acetonitrile and tetrahydrofuran and after recrystallization affords the linear coordination polymer [MnII(CH3CN)2(OTf)2]n. Each distorted octahedral manganese(II) center in the polymeric chain has trans-acetonitriles and the remaining equatorial coordination positions are occupied by the bridging triflate anions. Dissolving [MnII(CH3CN)2(OTf)2]n in equal volumes of acetonitrile and pyridine followed by recrystallization with diethyl ether yields trans-[MnII(C5H5N)4(OTf)2]. The distorted octahedral geometry of the manganese center features monodentate trans-triflate anions and four equatorial pyridines. Exposure of either [MnII(CH3CN)2(OTf)2]n or [MnII(C5H5N)4(OTf)2] to water readily gives [MnII(H2O)6](OTf)2. XRD reveals hydrogen-bonding interactions between the [MnII(H2O)6]2+ cation and the triflate anion. All three of these species are easily crystallized and provide convenient sources of manganese(II) for further synthetic elaboration.