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Toward the Synthesis of Iron, Cobalt, and Nickel Metal Nanoclusters.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Toward the Synthesis of Iron, Cobalt, and Nickel Metal Nanoclusters./
作者:	Touchton, Alexander J.
面頁冊數:	1 online resource (731 pages)
附註:	Source: Dissertations Abstracts International, Volume: 84-02, Section: B.
Contained By:	Dissertations Abstracts International84-02B.
標題:	Inorganic chemistry. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29254671click for full text (PQDT)
ISBN:	9798841776208

Toward the Synthesis of Iron, Cobalt, and Nickel Metal Nanoclusters.
Touchton, Alexander J.

Toward the Synthesis of Iron, Cobalt, and Nickel Metal Nanoclusters. - 1 online resource (731 pages)

Source: Dissertations Abstracts International, Volume: 84-02, Section: B.

Thesis (Ph.D.)--University of California, Santa Barbara, 2022.

Includes bibliographical references

The Ni complex, bis(trityl)nickel (2.1), was sought as a Ni(0) synthon for Ni metal nanocluster synthesis. Reinvestigation of 2.1, originally reported by Wilke in 1966, confirmed an η3-binding mode for the trityl ligands by X-ray crystallography and NMR spectroscopy an. Complex 2.1 to serves as a Ni(0) synthon, reacting with neutral donor ligands, CO and PPh3, to form the appropriate [NiL4] (L = CO, PPh3) complexes and trityl radical, as Gomberg's dimer. The utility of 2.1 in metal nanocluster synthesis was probed by heating 2.1 with PPh3 (2 equiv), which resulted in the formation of the Ni phosphinidene cluster, [Ni3(PPh)(PPh2)2(PPh3)3] (2.3), which is formed by P-C cleavage in PPh3. Further efforts to develop homoleptic trityl complexes of the first-row transition metals led to bis(trityl)iron (3.1), the second ever homoleptic trityl transition metal complex. Complex 3.1 features an η5-binding mode to its trityl ligands, forming an example of an edge-bridged open ferrocene complex. Diamagnetic 3.1 was characterized further by 57Fe Mossbauer spectroscopy, X-ray crystallography, cyclic voltammetry, and NMR spectroscopy. A methylene chloride solution of 3.1 slowly reacts with excess CO to form [Fe(CO)5] and Gomberg's dimer, demonstrating the use of 3.1 as an Fe(0) synthon. Heating 3.1 with P(OMe)3 (5 equiv) resulted in the formation of a piano stool Fe(0) complex, [(μ,η4:η4-Ph2CC6H5C6H5CPh2)(Fe(P(OMe)3)3)2] (3.2), which features the novel o,o-isomer of Gomberg's dimer bound by two [Fe0(P(OMe)3)3] fragments via η4 interactions.A reinvestigation of Muetterties' [Ni4(CNtBu)7] (4.1) and the related [Ni8(CNtBu)12]n+ (n = 0, 1, 2) clusters is reported. The clusters [Ni8(CNtBu)12][X] (X = Cl, I; 4.2, 4.5) were characterized by X-ray crystallography and NMR spectroscopy. Importantly, these clusters adopt a folded nanosheet structure composed of two bisecting [Ni4] sheets. Additionally, structural characterization of [Ni8(CNtBu)10Cl2] (4.3), [Ni8(CNtBu)10l2] (4.7), and [Ni8(CNtBu)12][I]2 (4.6) is provided, which all adopt folded nanosheet structures. Lastly, I report [Ni13C(CNtBu)16Cl][Cl] (4.5), whose carbide atom is derived from residual CHCl3 in tBuNC. The folded nanosheet structures in clusters 4.2-4.7 possess isocyanide ligands reduced to [tBuNC]2- ligands. This work underscores the challenges in achieving a metal nanocluster with a compact metallic core and the difficulty in predicting nanocluster shapes based on formula alone.In situ NMR spectroscopy and ESI-MS were used to probe the formation of thiolate-protected Ni metal nanoclusters, derived using a novel synthetic approach. Treatment of a solution of [Ni(1,5-cod)2] with PEt3 and diphenyl disulfide results in the formation of [Ni3(SPh)4(PEt3)3] (5.1) and unreacted [Ni(1,5-cod)2]. On standing, 5.1 reacts with an additional equivalent of [Ni(1,5-cod)2] to form [Ni4(S)(Ph)(SPh)3(PEt3)3] (5.2), which contains a Ni-Ph moiety and sulfide ligand produced from oxidative addition across a S-C bond. Subsequent heating of the solution produces a mixture of Ni sulfide clusters, [Ni5(S)2(SPh)2(PEt3)5] (5.3) and [Ni8(S)5(PEt3)7] (5.4). Analysis of the in situ NMR and ESI-MS data are well supported by the independent synthesis and characterization of 5.1-5.4. Ultimately, these results suggest that the tendency of Ni(0) to oxidatively add across S-C bonds in thiolate ligands is a major obstacle to synthesizing thiolate-protected Ni APNCs.In a reinvestigation of [Ni23Se12(PEt3)13], originally reported by Steigerwald, [Ni23Se12Cl3(PEt3)10] (6.1), was isolated instead as a product of adventitious chloride. A comparison of structures of 6.1 and Steigerwald's cluster indicate that the two are isostructural, indicating that three P atoms in the original structure are better formulated as Cl atoms. Higher yielding syntheses of 6.1 and its bromide analog, [Ni23Se12Br3(PEt3)10] (6.3), were developed. Both 6.1 and 6.3 features a remarkable hcp [Ni13]7+ kernels, which suggests partial Ni(0) character. Further characterization 6.1 and 6.3 by NMR spectroscopy, ESI-MS, UV-vis spectroscopy, X-ray fluorescence, and multiwavelength anomalous diffraction (MAD) are reported. Additionally, solid-state and solution-state magnetometry of 6.1 indicates a closed shell ground state, suggesting 6.1 is ultimately different than Steigerwald's original cluster. Importantly, the MAD analysis of 6.1 indicates that Ni(0) character is localized on the [Ni13]7+ kernel, indicating Ni(0/II) charge partitioning in 6.1. This MAD analysis places on firm footing that 6.1 is a Ni metal nanocluster.A new strategy for accessing Ni metal nanoclusters featuring phosphine and chalcogenide ligands is presented. Heating a solution of [Ni(1,5-cod)2] and PEt3 with elemental chalcogen results in the formation of low-valent Ni chalcogenide clusters with metal-like kernels. Synthesis and characterization of [Ni30S16(PEt3)11] (7.1) and [Ni26S14(PEt3)10] (7.2) are reported, both of which are paramagnetic low-valent Ni sulfide nanoclusters featuring compact Ni metal like cores. When selenium is used as the chalcogen, a complex mixture of [Ni26Se14(PEt3)10] (7.3) and [Ni31Se16(PEt3)12] (7.4), among others clusters, are formed. X-ray crystallographic analysis of 7.1-7.4 are discussed in detail. Remarkably, 7.3 is isostructural with its sulfide analog, 7.2. [Ni31Se16(PEt3)12] (7.4) features a hcp [Ni22] kernel, which is the first instance of Ni kernel fusion-a phenomenon commonly seen in Au metal nanoclusters. Analysis of the reaction mixtures by ESI-MS suggest that when chalcogens Se and Te are used, even larger Ni metal nanoclusters are generated, although their formulations are not certainly known.Extension of this synthetic strategy to cobalt produced the first Co metal nanocluster ever reported: [Co21S14(PEt3)12] (8.4), which features a fcc [Co13] kernel, the first metal-like kernel reported for Co. Preliminary characterization of 8.4 by NMR spectroscopy and ESI-MS is discussed. Complex 8.4 is isostructural with the Ni analog, [Ni21Se14(P(Ph)Et2)12], providing a rare opportunity to probe electronic structure in isostructural metal APNCs with substantial differences in valence electrons. Also reported are the syntheses of low-valent Co cubane clusters, [Z Co8S6(PEt3)8] (Z = nothing, Co, S2-; 8.2, 8.3, 8.1). Lastly, characterization of the diamagnetic CoI trityl complex, [Co(η5-CPh3)(1,5-cod)] (8.5), by NMR spectroscopy, ESI-MS, and X-ray crystallography is presented.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2023

Mode of access: World Wide Web

ISBN: 9798841776208Subjects--Topical Terms:

3173556
Inorganic chemistry.
Subjects--Index Terms:

Inorganic synthesisIndex Terms--Genre/Form:

542853
Electronic books.

Toward the Synthesis of Iron, Cobalt, and Nickel Metal Nanoclusters.
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100 1 $a Touchton, Alexander J. $3 3698105
245 1 0 $a Toward the Synthesis of Iron, Cobalt, and Nickel Metal Nanoclusters.
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500 $a Source: Dissertations Abstracts International, Volume: 84-02, Section: B.
500 $a Advisor: Hayton, Trevor W.
502 $a Thesis (Ph.D.)--University of California, Santa Barbara, 2022.
504 $a Includes bibliographical references
520 $a The Ni complex, bis(trityl)nickel (2.1), was sought as a Ni(0) synthon for Ni metal nanocluster synthesis. Reinvestigation of 2.1, originally reported by Wilke in 1966, confirmed an η3-binding mode for the trityl ligands by X-ray crystallography and NMR spectroscopy an. Complex 2.1 to serves as a Ni(0) synthon, reacting with neutral donor ligands, CO and PPh3, to form the appropriate [NiL4] (L = CO, PPh3) complexes and trityl radical, as Gomberg's dimer. The utility of 2.1 in metal nanocluster synthesis was probed by heating 2.1 with PPh3 (2 equiv), which resulted in the formation of the Ni phosphinidene cluster, [Ni3(PPh)(PPh2)2(PPh3)3] (2.3), which is formed by P-C cleavage in PPh3. Further efforts to develop homoleptic trityl complexes of the first-row transition metals led to bis(trityl)iron (3.1), the second ever homoleptic trityl transition metal complex. Complex 3.1 features an η5-binding mode to its trityl ligands, forming an example of an edge-bridged open ferrocene complex. Diamagnetic 3.1 was characterized further by 57Fe Mossbauer spectroscopy, X-ray crystallography, cyclic voltammetry, and NMR spectroscopy. A methylene chloride solution of 3.1 slowly reacts with excess CO to form [Fe(CO)5] and Gomberg's dimer, demonstrating the use of 3.1 as an Fe(0) synthon. Heating 3.1 with P(OMe)3 (5 equiv) resulted in the formation of a piano stool Fe(0) complex, [(μ,η4:η4-Ph2CC6H5C6H5CPh2)(Fe(P(OMe)3)3)2] (3.2), which features the novel o,o-isomer of Gomberg's dimer bound by two [Fe0(P(OMe)3)3] fragments via η4 interactions.A reinvestigation of Muetterties' [Ni4(CNtBu)7] (4.1) and the related [Ni8(CNtBu)12]n+ (n = 0, 1, 2) clusters is reported. The clusters [Ni8(CNtBu)12][X] (X = Cl, I; 4.2, 4.5) were characterized by X-ray crystallography and NMR spectroscopy. Importantly, these clusters adopt a folded nanosheet structure composed of two bisecting [Ni4] sheets. Additionally, structural characterization of [Ni8(CNtBu)10Cl2] (4.3), [Ni8(CNtBu)10l2] (4.7), and [Ni8(CNtBu)12][I]2 (4.6) is provided, which all adopt folded nanosheet structures. Lastly, I report [Ni13C(CNtBu)16Cl][Cl] (4.5), whose carbide atom is derived from residual CHCl3 in tBuNC. The folded nanosheet structures in clusters 4.2-4.7 possess isocyanide ligands reduced to [tBuNC]2- ligands. This work underscores the challenges in achieving a metal nanocluster with a compact metallic core and the difficulty in predicting nanocluster shapes based on formula alone.In situ NMR spectroscopy and ESI-MS were used to probe the formation of thiolate-protected Ni metal nanoclusters, derived using a novel synthetic approach. Treatment of a solution of [Ni(1,5-cod)2] with PEt3 and diphenyl disulfide results in the formation of [Ni3(SPh)4(PEt3)3] (5.1) and unreacted [Ni(1,5-cod)2]. On standing, 5.1 reacts with an additional equivalent of [Ni(1,5-cod)2] to form [Ni4(S)(Ph)(SPh)3(PEt3)3] (5.2), which contains a Ni-Ph moiety and sulfide ligand produced from oxidative addition across a S-C bond. Subsequent heating of the solution produces a mixture of Ni sulfide clusters, [Ni5(S)2(SPh)2(PEt3)5] (5.3) and [Ni8(S)5(PEt3)7] (5.4). Analysis of the in situ NMR and ESI-MS data are well supported by the independent synthesis and characterization of 5.1-5.4. Ultimately, these results suggest that the tendency of Ni(0) to oxidatively add across S-C bonds in thiolate ligands is a major obstacle to synthesizing thiolate-protected Ni APNCs.In a reinvestigation of [Ni23Se12(PEt3)13], originally reported by Steigerwald, [Ni23Se12Cl3(PEt3)10] (6.1), was isolated instead as a product of adventitious chloride. A comparison of structures of 6.1 and Steigerwald's cluster indicate that the two are isostructural, indicating that three P atoms in the original structure are better formulated as Cl atoms. Higher yielding syntheses of 6.1 and its bromide analog, [Ni23Se12Br3(PEt3)10] (6.3), were developed. Both 6.1 and 6.3 features a remarkable hcp [Ni13]7+ kernels, which suggests partial Ni(0) character. Further characterization 6.1 and 6.3 by NMR spectroscopy, ESI-MS, UV-vis spectroscopy, X-ray fluorescence, and multiwavelength anomalous diffraction (MAD) are reported. Additionally, solid-state and solution-state magnetometry of 6.1 indicates a closed shell ground state, suggesting 6.1 is ultimately different than Steigerwald's original cluster. Importantly, the MAD analysis of 6.1 indicates that Ni(0) character is localized on the [Ni13]7+ kernel, indicating Ni(0/II) charge partitioning in 6.1. This MAD analysis places on firm footing that 6.1 is a Ni metal nanocluster.A new strategy for accessing Ni metal nanoclusters featuring phosphine and chalcogenide ligands is presented. Heating a solution of [Ni(1,5-cod)2] and PEt3 with elemental chalcogen results in the formation of low-valent Ni chalcogenide clusters with metal-like kernels. Synthesis and characterization of [Ni30S16(PEt3)11] (7.1) and [Ni26S14(PEt3)10] (7.2) are reported, both of which are paramagnetic low-valent Ni sulfide nanoclusters featuring compact Ni metal like cores. When selenium is used as the chalcogen, a complex mixture of [Ni26Se14(PEt3)10] (7.3) and [Ni31Se16(PEt3)12] (7.4), among others clusters, are formed. X-ray crystallographic analysis of 7.1-7.4 are discussed in detail. Remarkably, 7.3 is isostructural with its sulfide analog, 7.2. [Ni31Se16(PEt3)12] (7.4) features a hcp [Ni22] kernel, which is the first instance of Ni kernel fusion-a phenomenon commonly seen in Au metal nanoclusters. Analysis of the reaction mixtures by ESI-MS suggest that when chalcogens Se and Te are used, even larger Ni metal nanoclusters are generated, although their formulations are not certainly known.Extension of this synthetic strategy to cobalt produced the first Co metal nanocluster ever reported: [Co21S14(PEt3)12] (8.4), which features a fcc [Co13] kernel, the first metal-like kernel reported for Co. Preliminary characterization of 8.4 by NMR spectroscopy and ESI-MS is discussed. Complex 8.4 is isostructural with the Ni analog, [Ni21Se14(P(Ph)Et2)12], providing a rare opportunity to probe electronic structure in isostructural metal APNCs with substantial differences in valence electrons. Also reported are the syntheses of low-valent Co cubane clusters, [Z Co8S6(PEt3)8] (Z = nothing, Co, S2-; 8.2, 8.3, 8.1). Lastly, characterization of the diamagnetic CoI trityl complex, [Co(η5-CPh3)(1,5-cod)] (8.5), by NMR spectroscopy, ESI-MS, and X-ray crystallography is presented.
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650 4 $a Nanoscience. $3 587832
650 4 $a Chemistry. $3 516420
650 4 $a Chemical engineering. $3 560457
653 $a Inorganic synthesis
653 $a Nanocluster
653 $a Nanoparticle
653 $a Organometallic chemistry
653 $a Trityl radical
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773 0 $t Dissertations Abstracts International $g 84-02B.
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