Reactive Magnesium Nanoparticles to Perform Reactions in Suspension
Christian Ritschel, Carsten Donsbach, Claus Feldmann
Abstract
Abstract Zerovalent magnesium (Mg(0)) nanoparticles are prepared in the liquid phase (THF) by reduction of MgBr 2 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 ( d 101 =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 (Ph 3 SiCl), trichlorphenylsilane (PhSiCl 3 ), 9H‐carbazole (Hcbz), 7‐azaindole (Hai), 1,8‐diaminonaphthalene (H 4 nda) and N,N’‐bis(α‐pyridyl)‐2,6‐diaminopyridine (H 2 tpda) as exemplary starting materials. The reactions result in the formation of 1,1’‐biadamantane ( 1 ), [MgCl 2 (thf) 2 ]×Ph 6 Si 2 ( 2 ), [Mg 9 (thf) 14 Cl 18 ] ( 3 ), [Mg(cbz) 2 (thf) 3 ] ( 4 ), [Mg 4 O(ai) 6 ]×1.5 C 7 H 8 ( 5 ), [Mg 4 (H 2 nda) 4 (thf) 4 ] ( 6 ) and [Mg 3 (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 Mg 2+ complexes with multidentate ligands illustrates the potential of the oxidative approach to obtain novel compounds with Mg(0) nanoparticles in the liquid phase.