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(18-crown-6)(NH3)3)][SMes*]2·2THF, 2 (Mes* = 2,4,6-tBu3C6H2), and the contact
triple [Ca(18-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(μ2-Li)2(THF)4], 4, isolated as the product of
a salt elimination reaction between CaBr2 and 2 equiv of [Li(THF)nS-2,4,6-iPr3C6H2]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 IR and
NMR spectroscopy.