Syntheses and structure determinations of calcium thiolates

The exploration of synthetic methodologies toward heavy alkaline-earth chalcogenolates resulted in the preparation and structural characterization of a family of calcium thiolates, including [Ca(SC6F5)(2)(py)(4)], 1 (py = pyridine), the separated ion-triple [Ca(l8-crown-6)(NH3)(3))][SMes*](2). 2THF, 2 (Mes* = 2,4,6-tBu(3)C(6)H(2)), and the contact triple [Ca(l8-crown-6)(SMes*)(2)]. THF, 3. Compound 1 was prepared by treating [Ca(N(SiMe3)(2))(2)](2) with 4 equiv of HSC6F5 under addition of pyridine. The thiolates 2 and 3 were synthesized by treatment of calcium metal dissolved in dry, liquid NH3 under addition of 2 equiv of HSMes* and crown ether or, alternatively, by the reduction of Mes*SSMes* with calcium metal in dry, liquid ammonia. We also report two reaction products isolated during attempted calcium thiolate syntheses: [CaBr4(THF)(2)(mu(2)-Li)(2)(THF)(4)], 4, isolated as the product of a salt elimination reaction between CaBr2 and 2 equiv of [Li(THF)(n)S-2,4,6-(Pr3C6H2)-Pr-i](m). [(NH4)(py)(SC6F5)], 5, was obtained as the sole product in the reaction of metallic calcium with HSC6F5 in liquid ammonia under addition of pyridine. All compounds were characterized by single-crystal X-ray crystallography in addition to LR and NMR spectroscopy.