Reactive Magnesium Nanoparticles to Perform Reactions in Suspension

Abstract

AbstractZerovalent magnesium (Mg(0)) nanoparticles are prepared in the liquid phase (THF) by reduction of MgBr2 either with lithium naphthalenide ([LiNaph]) or lithium biphenyl ([LiBP]). [LiBP]‐driven reduction results in smaller Mg(0) nanoparticles (10.3±1.7 nm) than [LiNaph]‐driven reduction (28.5±4 nm). The as‐prepared Mg(0) nanoparticles are monocrystalline (d101=245±5 pm) for both types of reduction. Their reactivity is probed by liquid‐phase reaction (THF, toluene) in suspension near room temperature (20–120 °C) with 1‐bromoadamantane (AdBr), chlortriphenylsilane (Ph3SiCl), trichlorphenylsilane (PhSiCl3), 9H‐carbazole (Hcbz), 7‐azaindole (Hai), 1,8‐diaminonaphthalene (H4nda) and N,N’‐bis(α‐pyridyl)‐2,6‐diaminopyridine (H2tpda) as exemplary starting materials. The reactions result in the formation of 1,1’‐biadamantane (1), [MgCl2(thf)2]×Ph6Si2 (2), [Mg9(thf)14Cl18] (3), [Mg(cbz)2(thf)3] (4), [Mg4O(ai)6]×1.5 C7H8 (5), [Mg4(H2nda)4(thf)4] (6) and [Mg3(tpda)3] (7) with 40–80 % yield. 1 and 2 show the reactivity of Mg(0) nanoparticles for C−C and Si−Si coupling reactions with sterically demanding starting materials. 3–7 represent new coordination compounds using sterically demanding N−H‐acidic amines as starting materials. The formation of multinuclear Mg2+ complexes with multidentate ligands illustrates the potential of the oxidative approach to obtain novel compounds with Mg(0) nanoparticles in the liquid phase.