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Jeung Hun Park - One of the best experts on this subject based on the ideXlab platform.

  • control of electron beam induced au nanocrystal growth kinetics through solution chemistry
    Nano Letters, 2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffu...

Frances M Ross - One of the best experts on this subject based on the ideXlab platform.

  • control of electron beam induced au nanocrystal growth kinetics through solution chemistry
    Nano Letters, 2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffu...

  • Control of Electron Beam-Induced Au Nanocrystal Growth Kinetics through Solution Chemistry
    2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffusion model is required that explicitly accounts for the species H+ and Cl–. The model highlights the necessity of considering all species present when interpreting kinetic data obtained from beam-induced processes, and suggest conditions under which growth rates can be controlled with higher precision

Rei Kinjo - One of the best experts on this subject based on the ideXlab platform.

  • diverse reactivity of a tricoordinate organoboron l2phb l oxazol 2 ylidene towards alkali metal group 9 metal and coinage metal precursors
    Chemical Science, 2015
    Co-Authors: Ling Bing Kong, Rakesh Ganguly, Rei Kinjo
    Abstract:

    The reactivity of a tricoordinate organoboron L2PhB: (L = oxazol-2-ylidene) 1 towards metal precursors and its coordination chemistry were comprehensively studied. While the boron center in 1 is reluctant to coordinate to the alkali metals in their trifluoromethanesulfonate salts (MOTf) (M = Li, Na, K), the unprecedented compound 2 containing two L2PhB: units linked by a cyclic Li(OTf)2Li spacer was obtained from the reaction of 1 with LiOTf. Treatment of 1 with group 9 metal complexes [MCl(COD)]2 (M = Rh, Ir) afforded the first zwitterionic rhodium(I)–boronium complex 3 and the iridium(III)–borane complex 4, respectively. The reaction pathway may involve C–H activation followed by proton migration from the metals to the boron center, demonstrating the first example of the deprotonation of metal hydrides by a basic boron. In the reactions with coinage metals, 1 could act as a two-electron reducing agent towards the metal Chlorides MCl (M = Cu, Ag, Au). Meanwhile, the reaction of 1 with Gold Chloride supported by a N-heterocyclic carbene (NHC) produced a heteroleptic cationic Gold complex [(L2PhB)Au(NHC)]Cl (6) featuring both carbene and L2PhB: ligands on the Gold atom. In contrast, an isolable Gold Chloride complex (L2PhB)AuCl (8) was obtained by direct complexation between 1 and triphenylphosphine-Gold Chloride via ligand exchange. X-ray diffraction analysis and computational studies revealed the nature of the B:→Au bonding interaction in complexes 6 and 8. Natural Population Analysis (NPA) and Natural Bond Orbital (NBO) analysis support the strong σ-donating property of the L2PhB: ligand. Moreover, preliminary studies showed that complex 8 can serve as an efficient precatalyst for the addition of X–H (X = N, O, C) to alkynes under ambient conditions, demonstrating the first application of a metal complex featuring a neutral boron-based ligand in catalysis.

Nicholas M Schneider - One of the best experts on this subject based on the ideXlab platform.

  • control of electron beam induced au nanocrystal growth kinetics through solution chemistry
    Nano Letters, 2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffu...

  • Control of Electron Beam-Induced Au Nanocrystal Growth Kinetics through Solution Chemistry
    2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffusion model is required that explicitly accounts for the species H+ and Cl–. The model highlights the necessity of considering all species present when interpreting kinetic data obtained from beam-induced processes, and suggest conditions under which growth rates can be controlled with higher precision

Joseph M Grogan - One of the best experts on this subject based on the ideXlab platform.

  • control of electron beam induced au nanocrystal growth kinetics through solution chemistry
    Nano Letters, 2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffu...

  • Control of Electron Beam-Induced Au Nanocrystal Growth Kinetics through Solution Chemistry
    2015
    Co-Authors: Jeung Hun Park, Nicholas M Schneider, Joseph M Grogan, M C Reuter, Haim H Bau, S Kodambaka, Frances M Ross
    Abstract:

    Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of Gold Chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffusion model is required that explicitly accounts for the species H+ and Cl–. The model highlights the necessity of considering all species present when interpreting kinetic data obtained from beam-induced processes, and suggest conditions under which growth rates can be controlled with higher precision