A simple solution synthesis of germanium (Ge 0 ) nanowires under mild conditions (<400 °C and 1 atm) was demonstrated using germanium 2,6 dibutylphenoxide Ge(DBP) 2 (1) as the precursor where DBP = OC 6 H 3 (C(CH 3 ) 3 ) 2 -2,6. Compound 1, synthesized from Ge(NR 2 ) 2 where R = SiMe 3 and two equivalents of DBP-H, was characterized as a mononuclear species by single crystal X-ray diffraction. Dissolution of 1 in oleylamine, followed by rapid injection into a 1-octadecene solution heated to 300 °C under an atmosphere of Ar, led to the formation of Ge 0 nanowires. The Ge 0 nanowires were characterized by transmission electron microscopy (TEM), X-ray diffraction analysis, and Fourier transform infrared spectroscopy. These characterizations revealed that the nanowires are single crystalline in the cubic phase and coated with oleylamine surfactant. We also observed that the nanowire length (0.1 to 10 µm) increases with increasing temperature (285 to 315°C) and time (5 to 60 min). Two growth mechanisms are proposed based on the TEM images intermittently taken during the growth process as a function of time: (1) self-seeding mechanism where one of two overlapping nanowires serves as a seed, while the other continues to grow as a wire and (2) self-assembly mechanism where an aggregate of small rods (< 50 nm in diameter) recrystallize on the tip of a longer wire, extending its length.

A series of cerium alkoxides were synthesized from the reaction of Ce{N[Si(CH3)3]2}3 and the appropriate alcohol: neopentyl alcohol [H–OCH2C(CH3)3 = H‐ONep], tert‐butyl alcohol [H–OC(CH3)3 = H‐OtBu], o‐(tert‐butyl)phenol {H–OC6H4[C(CH3)3]‐2 = H‐oBP}, 2,6‐dimethylphenol [H–OC6H3(CH3)2‐2,6 = H‐DMP], 2,6‐diisopropylphenol {H–OC6H3[CH(CH3)2]2‐2,6 = H‐DIP}, 2,6‐di‐tert‐butylphenol {H–OC6H3[C(CH3)3]2‐2,6 = H‐DBP}, or 2,6‐diphenylphenol [H–OC6H3(C6H5)2‐2,6 = H‐DPP] using toluene (tol), tetrahydrofuran (THF) or pyridine (py). The precursors were characterized as [Ce(μ‐ONep)2(ONep)]4 (1), Ce4(μ3‐OtBu)3(μ‐OtBu)4(OtBu)5 (2), Ce3(μ3‐OtBu)3(μ‐OtBu)3(OtBu)3(H‐OtBu)2 (2a), Ce(oBP)3(THF)3 (3), [Ce(μ‐DMP)(DMP)2(solv)2]2 [solv = THF (4) and py (4a)], Ce(DIP)3(THF)3 (5), Ce(DPP)3(THF)2 (6). Once isolated, several of these species were further reacted with a series of sterically varied carboxylic acid modifiers including isobutyric acid [H–O2CCH(CH3)2 = H‐OPc] and trimethylacetic acid [H–O2CC(CH3)3 = H‐OBc]. The products were isolated as [Ce(OR)(μ‐ORc)(μc‐ORc)(py)]2 [OR = oBP, OBc: 7; DMP, OPc: 8; DMP, OBc: 9; DIP, OPc: 10]. These compounds were identified by single‐crystal X‐ray diffraction and powder XRD analyses. Several novel structure types are added to the cerium alkoxide family of compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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(OBut)2]2 and the appropriate ligand: N,N’-dibenzylethylenediamine (H2-DBED), tert-butanol (H-OBut), 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(μc-DBED)]2 (1, μc= bridging chelating), [Ge(μ-DMP)(DMP)]2 (2), Ge(DPP)2 (3), [Ge(μ-OBut)(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 GexSy. 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.

The synthesis and characterization of a series of neo-pentoxide (OCH2C(CH3)3 or ONep) derivatives of group 3 and the lanthanide (Ln) series' metals were undertaken via an amide/alcohol exchange route. Surprisingly, the products isolated and characterized by single-crystal X-ray diffraction yielded isostructural species for every trivalent cation studied: [Ln(mu-ONep)2(ONep)]4 [Ln=Sc (1), Y (2), La (3), Ce (4), Pr (5), Nd (6), Sm (7), Eu (8), Gd (9), Tb (10), Dy (11), Ho (12), Er (13), Tm (14), Yb (15), Lu (16)]. Compounds 3, 4, 6, and 11 have been previously reported. Within this series of complexes, the Ln metal centers are oriented in a square with each Ln-Ln edge interconnected via two mu-ONep ligands; each metal center also binds one terminal ONep ligand. NMR data of 1-3 indicate that the solid-state structure is retained in solution. FTIR spectroscopy (KBr pellet) revealed the presence of significant Ln---H-C interactions within one set of the bridging ONep ligands in all cases; the stretching frequencies of these C-H bonds appear to increase in magnitude with decrease in metal ion radius. These complexes were used to generate nanoparticles through solution hydrolysis routes, resulting in the formation of lanthanide oxide nanoparticles and rods. The emission properties of these ceramics were preliminarily investigated using UV-vis and PL measurements.