Synthesis and Characterization of Germanium Coordination Compounds for Production of Germanium Nanomaterials

A series of novel germanium(II) precursors was synthesized to initiate an investigation between the precursors' structures and the morphologies of the resulting nanoparticles. The precursors were synthesized from the reaction of Ge[N(SiMe₃)₂]₂ or [Ge(OBu^t)₂]₂ and the appropriate ligand: N,N'-dibenzylethylenediamine (H₂-DBED), tert-butanol (H-OBu^t), 2,6-di-methyl phenol (H-DMP), 2,6-di-phenyl phenol (H-DPP), tert-butyldimethylsilanol (H-DMBS), triphenylsilanol (H-TPS), triphenylsilanethiol (H-TPST), and benzenethiol (H-PS). The products were identified as: [Ge(μ_c-DBED)]₂ (1, μ_c= bridging chelating), [Ge(μ-DMP)(DMP)]₂ (2), Ge(DPP)₂ (3), [Ge(μ-OBu^t)(DMBS)]₂, (4), [Ge(μ-DMBS)(DMBS)]₂ (5), Ge(TPS)₃(H) (6), [Ge(μ-TPST)(TPST)]₂ (7), and Ge(PS)₄ (8). The Ge(II) metal centers were found to adopt a pyramidal geometry for 1, 2, 4, 5, 7, a bent arrangement for 3, and a tetrahedral coordination for the Ge(IV) species 6 and 8. Using a simple solution precipitation methodology, Ge(0) nanomaterials were isolated as dots and wires for the majority of precursors. Compound 7 led to the isolation of amorphous Ge_xS_y. The nanomaterials isolated were characterized by TEM, EDS, and powder XRD. A correlation between the precursor's arrangement and final observed nanomorphology was proffered as part of the 'precursor structure affect' phenomenon.