The reactions of
[{(iPrDipNacNac)Mg}2] 1 (iPrDipnacnac = HC(iPrCNDip)2) with
Ph3PO at 100 °C afforded the phosphinate complex
[(iPrDipNacNac)Mg(OPPh3)(OPPh2)] 3. Reactions of 1 with Ph3PE
(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 RNHCS
((MeCNR)2CS 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.