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Sharma P, Singh RR, Giri SS, Chen LY, Cheng MJ, Liu RS. Gold-Catalyzed Oxidation of Thioalkynes To Form Phenylthio Ketene Derivatives via a Noncarbene Route. Org Lett 2019; 21:5475-5479. [PMID: 31274331 DOI: 10.1021/acs.orglett.9b01768] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Gold-catalyzed oxidations of thioalkynes with 8-methylquinoline oxides afford 2-phenylthioketenes that can be trapped efficiently with alcohols. The synthetic utility is manifested by terminal and internal thioalkynes over a wide scope, bearing esters, ketones, alkyl, and oxime substituents. Our density functional theory calculations suggest that gold-catalyzed oxidations of terminal and internal thioalkynes with 8-methylquinoline oxides generate gold-bound ketene intermediates without the intermediacy of α-oxo gold carbene.
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Affiliation(s)
- Pankaj Sharma
- Frontier Research Center on Fundamental and Applied Sciences of Matters, Department of Chemistry , National Tsing-Hua University , Hsinchu , Taiwan , Republic of China
| | - Rahulkumar Rajmani Singh
- Frontier Research Center on Fundamental and Applied Sciences of Matters, Department of Chemistry , National Tsing-Hua University , Hsinchu , Taiwan , Republic of China
| | - Sovan Sundar Giri
- Frontier Research Center on Fundamental and Applied Sciences of Matters, Department of Chemistry , National Tsing-Hua University , Hsinchu , Taiwan , Republic of China
| | - Liang-Yu Chen
- Department of Chemistry , National Cheng Kung University , Tainan 701 , Taiwan , Republic of China
| | - Mu-Jeng Cheng
- Department of Chemistry , National Cheng Kung University , Tainan 701 , Taiwan , Republic of China
| | - Rai-Shung Liu
- Frontier Research Center on Fundamental and Applied Sciences of Matters, Department of Chemistry , National Tsing-Hua University , Hsinchu , Taiwan , Republic of China
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2
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Affiliation(s)
- Ritu Arora
- Computational Chemistry Laboratory, Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Kriti Kashyap
- Computational Chemistry Laboratory, Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Anshika Mittal
- Computational Chemistry Laboratory, Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Rita Kakkar
- Computational Chemistry Laboratory, Department of Chemistry, University of Delhi, Delhi 110007, India
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3
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Zhang J, Shan C, Zhang T, Song J, Liu T, Lan Y. Computational advances aiding mechanistic understanding of silver-catalyzed carbene/nitrene/silylene transfer reactions. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.12.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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4
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Affiliation(s)
| | - Richard Goddard
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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5
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Tskhovrebov AG, Goddard R, Fürstner A. Two Amphoteric Silver Carbene Clusters. Angew Chem Int Ed Engl 2018; 57:8089-8094. [PMID: 29733538 DOI: 10.1002/anie.201803246] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/27/2018] [Indexed: 01/09/2023]
Abstract
Two highly labile silver carbene cluster complexes are described, which are unique in that they mark the transition point at which the carbene center transmutes from a fairly common NHC-like nucleophilic behavior to an electrophilic character befitting reactive silver carbene intermediates of relevance in various catalytic transformations. This amphoteric character is the distinguishing attribute of a μ-bridged donor/donor carbene entity that connects two silver atoms of triangular or tetrahedral metallic core units.
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Affiliation(s)
| | - Richard Goddard
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
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6
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Ford A, Miel H, Ring A, Slattery CN, Maguire AR, McKervey MA. Modern Organic Synthesis with α-Diazocarbonyl Compounds. Chem Rev 2015; 115:9981-10080. [PMID: 26284754 DOI: 10.1021/acs.chemrev.5b00121] [Citation(s) in RCA: 1093] [Impact Index Per Article: 121.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | - Hugues Miel
- Almac Discovery Ltd. , David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | | | | | | | - M Anthony McKervey
- Almac Sciences Ltd. , Almac House, 20 Seagoe Industrial Estate, Craigavon BT63 5QD, United Kingdom
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7
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Xia N, Yang J, Wu Z. Fast, high-yield synthesis of amphiphilic Ag nanoclusters and the sensing of Hg(2+) in environmental samples. NANOSCALE 2015; 7:10013-10020. [PMID: 25891837 DOI: 10.1039/c5nr00705d] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report the high-yield (74%) synthesis of Ag30(Capt)18 (abbreviated as Ag30) in a very time-saving fashion (half an hour). The cluster composition was determined by high-resolution mass spectrometry combined with TG analysis, and the structure was probed by 1D and 2D NMR. Interestingly, the nanoclusters can dissolve in water and methanol, as well as in most organic solvents such as ethanol, acetone, acetonitrile, dichloromethane and ethyl acetate with the assistance of acetic acid. Such a good solubility in a range of various polar solvents was not reported previously in nanoclusters' research and is important for applications. An important result from this work is that Ag30 can sense a low concentration of Hg(2+) in environmental samples (including lake water and soil solution), indicating that Ag30 can be a potential colorimetric probe for Hg(2+). The sensing mechanism was revealed to be related to the anti-galvanic reduction process.
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Affiliation(s)
- Nan Xia
- Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences (CAS), Hefei 230031, Anhui, China.
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8
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Abstract
Nanoparticle catalysis has emerged as an active topic in organic synthesis. Of particular interest is the development of enabling methodologies to efficiently assemble complex molecules using nanoparticle catalysis. This Viewpoint highlights recent developments and discusses future perspectives in this emerging field.
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Affiliation(s)
- Huan Cong
- Department of Chemistry and Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, Boston, Massachusetts 02215, United States
| | - John A. Porco
- Department of Chemistry and Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, Boston, Massachusetts 02215, United States
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10
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11
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Gerstenberger BS, Lin J, Mimieux YS, Brown LE, Oliver AG, Konopelski JP. Structural characterization of an enantiomerically pure amino acid imidazolide and direct formation of the beta-lactam nucleus from an alpha-amino acid. Org Lett 2008; 10:369-72. [PMID: 18181633 PMCID: PMC2597468 DOI: 10.1021/ol7025922] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Decomposition of a diazo beta-ketoamide derived from N-trityl serine imidazolide and N-protected acetanilides provides, instead of the expected 3-acyloxindole product, an enantiomerically pure (EP) beta-lactam. The amino acid stereocenter is incorporated, the second chiral center is induced, and trityl protection of the beta-lactam ring is realized for the first time. The desired 3-acyloxindole is obtained from oxindole and Tr-Ser(OBn)-imidazole, the X-ray of which provides the first structural determination of an EP amino acid imidazolide.
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Affiliation(s)
- Brian S. Gerstenberger
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California. 95064
| | - Jinzhen Lin
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California. 95064
| | - Yvette S. Mimieux
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California. 95064
| | - Lauren E. Brown
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California. 95064
| | - Allen G. Oliver
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California. 95064
| | - Joseph P. Konopelski
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California. 95064
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12
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Sardar R, Park JW, Shumaker-Parry JS. Polymer-induced synthesis of stable gold and silver nanoparticles and subsequent ligand exchange in water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:11883-9. [PMID: 17918982 DOI: 10.1021/la702359g] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A simple, inexpensive, single-step synthesis of gold and silver nanoparticles using poly(allylamine) (PAAm) as a reducing and stabilizing agent is reported. The synthetic process was carried out in aqueous solution, making the method versatile and environmentally friendly. The synthesized polymer-stabilized nanoparticles are stable in water without particle aggregation at room temperature for at least a month. We demonstrate successful ligand exchange on the polymer-stabilized gold nanoparticles (AuNPs) with a variety of omega-functionalized acid-, alcohol-, amine-, and biotin-terminated alkylthiols. The methodologies, including ligand exchange, also are applicable for the generation of finely dispersed silver nanoparticles. The synthesized gold and silver nanoparticles are characterized by UV-visible absorption spectroscopy and transmission electron microscopy (TEM). The different ligand-stabilized AuNPs are also analyzed by Fourier transform infrared (FTIR) spectroscopy.
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Affiliation(s)
- Rajesh Sardar
- Department of Chemistry, University of Utah, 1400 East 315 South, Room 2020, Salt Lake City, Utah 84112, USA
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13
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Belsito E, Di Gioia ML, Greco A, Leggio A, Liguori A, Perri F, Siciliano C, Viscomi MC. N-Methyl-N-nosyl-β3-amino Acids. J Org Chem 2007; 72:4798-802. [PMID: 17539685 DOI: 10.1021/jo070438i] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
N-Methyl-beta(3)-amino acids are important building blocks in the synthesis of biologically active molecules. A very simple and efficient approach to transform natural alpha-amino acids into their corresponding N-methyl-beta(3)-amino acids is here presented. In the method, the key intermediates N-methyl-N-nosyl-alpha-aminoacyldiazomethanes are prepared in only one step, by a simple treatment of the corresponding N-nosyl-alpha-aminoacyl chlorides with diazomethane. The synthetic route takes advantage from the use of the nosyl group. This N-masking moiety activates the NH function, and the N-methylation can directly occur during the acylation step of diazomethane, rendering useless a second step that instead is shown to be necessary in all the classical procedures already reported for the preparation of N-methyl-beta(3)-amino acids. The Wolff rearrangement of N-methyl-N-nosyl-alpha-aminoacyldiazomethanes provides the corresponding N-methyl-N-nosyl-beta(3)-amino acids with total retention of the chiral configuration of the starting alpha-amino acids. No epimerization of the chiral carbon atom is observed also when N-methyl-N-nosyl-beta(3)-amino acids are transformed into chlorides and coupled with alpha-amino acid methyl esters to achieve model scaffolds for biologically important modified peptides.
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Affiliation(s)
- Emilia Belsito
- Dipartimento di Scienze Farmaceutiche, Università della Calabria, Via P. Bucci, Cubo 15/C, I-87036 Arcavacata di Rende (CS) - Italy
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14
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Li Z, He C. Recent Advances in Silver‐Catalyzed Nitrene, Carbene, and Silylene‐Transfer Reactions. European J Org Chem 2006. [DOI: 10.1002/ejoc.200500602] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Zigang Li
- Department of Chemistry, The University of Chicago, Chicago, IL 6063, USA
| | - Chuan He
- Department of Chemistry, The University of Chicago, Chicago, IL 6063, USA
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15
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Sudrik SG, Sharma J, Chavan VB, Chaki NK, Sonawane HR, Vijayamohanan KP. Wolff Rearrangement of α-Diazoketones Using in Situ Generated Silver Nanoclusters as Electron Mediators. Org Lett 2006; 8:1089-92. [PMID: 16524275 DOI: 10.1021/ol052981w] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] We report Wolff rearrangement of alpha-diazoketones by in situ generated silver nanoclusters (Ag(n)(), 2-4 nm) from silver(I) oxide (Ag(2)O) involving a nonclassical electron-transfer process. Our results show that Ag(n)()(+)/Ag(n)()(0) redox couple allows the initial removal of an electron from alpha-diazoketone and its back-donation after chemical reaction(s). Controlled potential coulometry (CPC) of various alpha-diazoketones results in the realization of Wolff-rearranged carboxylic acids in excellent yields.
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Affiliation(s)
- Surendra G Sudrik
- Division of Organic Chemistry Technology, Physical and Materials Chemistry Division, and Chemical Engineering & Process Development Division, National Chemical Laboratory, Pune-411008, India
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16
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Sudrik SG, Chaki NK, Chavan VB, Chavan SP, Chavan SP, Sonawane HR, Vijayamohanan K. Silver Nanocluster Redox-Couple-Promoted Nonclassical Electron Transfer: An Efficient Electrochemical Wolff Rearrangement of α-Diazoketones. Chemistry 2006; 12:859-64. [PMID: 16196073 DOI: 10.1002/chem.200500696] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this work we report the unique electrocatalytic role of benzoic acid protected silver nanoclusters (Ag(n), mean core diameter 2.5 nm) in the Wolff rearrangement (Scheme 1) of alpha-diazoketones. More specifically, the presence of a Ag(n) (0)/Ag(n) (+) redox couple facilitates a nonclassical electron-transfer process, involving chemical reaction(s) interposed between two electron-transfer steps occurring in opposite directions. Consequently, the net electron transfer between the electron mediator (Ag(n)) and alpha-diazoketone is zero. In-situ UV-visible studies using pyridine as a nucleophilic probe indicate the participation of alpha-ketocarbene/ketene as important reaction intermediates. Controlled potential coulometry of alpha-diazoketones using Ag(n) as the anode results in the formation of Wolff rearranged carboxylic acids in excellent yield, without sacrificing the electrocatalyst.
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Affiliation(s)
- Surendra G Sudrik
- Division of Organic Chemistry: Technology, National Chemical Laboratory, Pune, India
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17
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Chaki NK, Singh P, Dharmadhikari CV, Vijayamohanan KP. Single-electron charging features of larger, dodecanethiol-protected gold nanoclusters: electrochemical and scanning tunneling microscopy studies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:10208-10217. [PMID: 15518515 DOI: 10.1021/la048489n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this report, we demonstrate the single-electron charging features of larger-sized (ca. 3.72 nm) Au nanoclusters protected with dodecanethiol [approximate composition, Au1415(RS)328] using combined electrochemical and scanning tunneling microscopic (STM) studies. In particular, these nanoclusters show a highly populated single-electron charging peak in voltammetric experiments, where the calculated capacitance is in good agreement with the experimentally obtained value of 1.6 aF. In comparison to the voltammetric studies, STM measurements over a single Au particle on the highly oriented pyrolytic graphite surface reveal nonlinear current-voltage (I-V) characteristics with a large central gap, signifying single-electron-transfer features. The I-V results demonstrate a clear Coulomb blockade effect with a central gap of around 0.2 eV, which is in good agreement with the orthodox theory for the double barrier tunnel junction system. The standard heterogeneous electron-transfer rate constant estimated from impedance measurements is found to be of 7.97 x 10(-6) cm.s(-1), suggesting that the process is very sluggish. Furthermore, diffusion coefficient (Dc) values calculated from chronoamperometry and impedance measurements are in good agreement with theoretically calculated values using the modified Stokes-Einstein equation. The electron-transfer rate constant estimated from cyclic voltammograms of adsorbed monolayer protected Au nanoclusters is found to be about 2 s(-1), which is slower than that reported for its smaller analogues.
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Affiliation(s)
- Nirmalya Kumar Chaki
- Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008, India
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18
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Sharma J, Mahima S, Kakade BA, Pasricha R, Mandale AB, Vijayamohanan K. Solvent-Assisted One-Pot Synthesis and Self-Assembly of 4-Aminothiophenol-Capped Gold Nanoparticles. J Phys Chem B 2004. [DOI: 10.1021/jp0482013] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jadab Sharma
- Physical and Materials Chemistry Division and Centre for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhaba Road, Pune-411008, India
| | - S. Mahima
- Physical and Materials Chemistry Division and Centre for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhaba Road, Pune-411008, India
| | - Bhalchandra A. Kakade
- Physical and Materials Chemistry Division and Centre for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhaba Road, Pune-411008, India
| | - Renu Pasricha
- Physical and Materials Chemistry Division and Centre for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhaba Road, Pune-411008, India
| | - A. B. Mandale
- Physical and Materials Chemistry Division and Centre for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhaba Road, Pune-411008, India
| | - K. Vijayamohanan
- Physical and Materials Chemistry Division and Centre for Materials Characterization, National Chemical Laboratory, Dr. Homi Bhaba Road, Pune-411008, India
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Driver TG, Woerpel KA. Mechanism of Silver-Mediated Di-tert-butylsilylene Transfer from a Silacyclopropane to an Alkene. J Am Chem Soc 2004; 126:9993-10002. [PMID: 15303873 DOI: 10.1021/ja0306563] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kinetic studies of the reactions of cyclohexene silacyclopropane 1 and monosubstituted alkenes in the presence of 5 mol % of (Ph3P)2AgOTf suggested a possible mechanism for silver-mediated di-tert-butylsilylene transfer. The kinetic order in cyclohexene silacyclopropane 1 was determined to be one. Inverse kinetic saturation behavior (rate inhibition) was observed in monosubstituted alkene and cyclohexene concentrations. Saturation kinetic behavior in catalyst concentration was observed. A reactive intermediate, a silylsilver complex, was observed using low temperature 29Si NMR spectroscopy. Competition experiments between substituted styrenes and a deficient amount of 1 correlated well with the Hammett equation and provided a rho value of -0.62 +/- 0.02 using sigmap constants. These data support a mechanism involving reversible silver-promoted di-tert-butylsilylene extrusion from 1 followed by irreversible concerted electrophilic attack of the silylsilver intermediate on the alkene.
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Affiliation(s)
- Tom G Driver
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA
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Cozzoli PD, Fanizza E, Comparelli R, Curri ML, Agostiano A, Laub D. Role of Metal Nanoparticles in TiO2/Ag Nanocomposite-Based Microheterogeneous Photocatalysis. J Phys Chem B 2004. [DOI: 10.1021/jp0379751] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. Davide Cozzoli
- Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy, and CNR-Istituto per i Processi Chimico Fisici (IPCF), sez. Bari, Via Orabona 4, 70126 Bari, Italy
| | - Elisabetta Fanizza
- Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy, and CNR-Istituto per i Processi Chimico Fisici (IPCF), sez. Bari, Via Orabona 4, 70126 Bari, Italy
| | - Roberto Comparelli
- Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy, and CNR-Istituto per i Processi Chimico Fisici (IPCF), sez. Bari, Via Orabona 4, 70126 Bari, Italy
| | - M. Lucia Curri
- Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy, and CNR-Istituto per i Processi Chimico Fisici (IPCF), sez. Bari, Via Orabona 4, 70126 Bari, Italy
| | - Angela Agostiano
- Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy, and CNR-Istituto per i Processi Chimico Fisici (IPCF), sez. Bari, Via Orabona 4, 70126 Bari, Italy
| | - Danièle Laub
- EPFL-CIME-Centre Interdisciplinaire de Microscopie Electronique, Batiment MXC, 1015 Lausanne, Switzerland
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Cozzoli PD, Comparelli R, Fanizza E, Curri ML, Agostiano A, Laub D. Photocatalytic Synthesis of Silver Nanoparticles Stabilized by TiO2Nanorods: A Semiconductor/Metal Nanocomposite in Homogeneous Nonpolar Solution. J Am Chem Soc 2004; 126:3868-79. [PMID: 15038741 DOI: 10.1021/ja0395846] [Citation(s) in RCA: 276] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel colloidal approach toward semiconductor/metal nanocomposites is presented. Organic-soluble anatase TiO(2) nanorods are used for the first time to stabilize Ag nanoparticles in optically clear nonpolar solutions in the absence of specific ligands for silver. Metallic silver is generated upon UV illumination of deaerated TiO(2) solutions containing AgNO(3). The Ag nanoparticles can be obtained in different size-morphological regimes as a function of the irradiation time, due to light-induced photofragmentation and ripening processes. A mechanism for the colloidal stabilization of the silver nanoparticles is tentatively suggested, which regards the TiO(2) nanorods as inorganic stabilizers, thus acting in the same manner as conventional surfactant molecules. The proposed photocatalytic approach offers a convenient method for producing TiO(2)/Ag nanocomposite systems with a certain control over the metal particle size without the use of surfactants and/or additives. Stable colloidal TiO(2)-nanorod-stabilized Ag nanoparticles can be potentially available for a number of applications that require "clean" metal surfaces, such as homogeneous organic catalysis, photocatalysis, and sensing devices.
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Affiliation(s)
- P Davide Cozzoli
- Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy
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22
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Chaki NK, Sharma J, Mandle AB, Mulla IS, Pasricha R, Vijayamohanan K. Size dependent redox behavior of monolayer protected silver nanoparticles (2–7 nm) in aqueous medium. Phys Chem Chem Phys 2004. [DOI: 10.1039/b312643a] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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