Low-Coordinate Magnesium Sulfide and Selenide Complexes

Abstract

The reactions of [{(iPrDipNacNac)Mg}2] 1 (iPrDipnacnac = HC(iPrCNDip)2) with Ph3PO at 100 °C afforded the phosphinate complex [(iPrDipNacNac)Mg(OPPh3)(OPPh2)] 3. Reactions of 1 with Ph3PE (E = S, Se) proceeded rapidly at room temperature to low-coordinate chalcogenide complexes [{(iPrDipNacNac)Mg}2(μ-S)] 4 and [{(iPrDipNacNac)Mg}2(μ-Se)] 5, respectively. Similarly, reactions of RNHCS ((MeCNR)2CS with R = Me, Et, or iPr) with 1 afforded NHC adducts of magnesium sulfide complexes, [{(iPrDipNacNac)Mg(RNHC)}(μ-S){Mg(iPrDipNacNac)}] 6, that could alternatively be obtained by adding the appropriate RNHC to sulfide complex 4. Complex 4 reacted with 1-adamantylazide (AdN3) to give [{(iPrDipNacNac)Mg}2(μ-SN3Ad)] 7 and can form various simple donor adducts in solution, of which [(iPrDipNacNac)Mg(OAd)}2(μ-S)] 8a (OAd = 2-adamantanone) was structurally characterized. The nature of the ionic Mg–E–Mg unit is described by solution and solid-state studies of the complexes and by DFT computational investigations.

Transdermal Hydrogen Sulfide Delivery Enabled by Open-Metal-Site Metal–Organic Frameworks

“…This short distance is consistent with reported magnesium complexes containing thiol or thiolate ligands, which have S···Mg bond distances of 2.3–2.4 Å (Table S5). − The few reported complexes in which either H 2 S or SH – is directly bound to a metal center, including Mn, Os, and Ru − complexes, also possess comparable metal–sulfur bond distances of 2.33–2.45 Å (Table S6). The interaction between H 2 S and the Mg 2+ site in Mg 2 (dobdc) is on the shorter side of this range likely due to the small size of the Mg 2+ cation.…”