1 resultado para 030106 Quality Assurance Chemometrics Traceability and Metrological Chemistry
em Digital Archives@Colby
Filtro por publicador
- Repository Napier (2)
- Aberdeen University (1)
- Aberystwyth University Repository - Reino Unido (2)
- Acceda, el repositorio institucional de la Universidad de Las Palmas de Gran Canaria. España (3)
- AMS Tesi di Dottorato - Alm@DL - Università di Bologna (16)
- AMS Tesi di Laurea - Alm@DL - Università di Bologna (1)
- Applied Math and Science Education Repository - Washington - USA (1)
- Aquatic Commons (18)
- ArchiMeD - Elektronische Publikationen der Universität Mainz - Alemanha (4)
- Archimer: Archive de l'Institut francais de recherche pour l'exploitation de la mer (1)
- Archive of European Integration (23)
- Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco (3)
- Aston University Research Archive (31)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (16)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP) (4)
- Bioline International (3)
- BORIS: Bern Open Repository and Information System - Berna - Suiça (49)
- Brock University, Canada (6)
- Bucknell University Digital Commons - Pensilvania - USA (2)
- Bulgarian Digital Mathematics Library at IMI-BAS (2)
- CaltechTHESIS (4)
- Cambridge University Engineering Department Publications Database (16)
- CentAUR: Central Archive University of Reading - UK (53)
- Chinese Academy of Sciences Institutional Repositories Grid Portal (12)
- Cochin University of Science & Technology (CUSAT), India (10)
- Coffee Science - Universidade Federal de Lavras (1)
- Collection Of Biostatistics Research Archive (1)
- Comissão Econômica para a América Latina e o Caribe (CEPAL) (4)
- CORA - Cork Open Research Archive - University College Cork - Ireland (3)
- Dalarna University College Electronic Archive (2)
- Deakin Research Online - Australia (99)
- Digital Archives@Colby (1)
- Digital Commons - Michigan Tech (2)
- Digital Commons @ DU | University of Denver Research (1)
- Digital Commons at Florida International University (5)
- Digital Peer Publishing (1)
- DigitalCommons@The Texas Medical Center (15)
- DigitalCommons@University of Nebraska - Lincoln (2)
- DRUM (Digital Repository at the University of Maryland) (2)
- Duke University (3)
- eResearch Archive - Queensland Department of Agriculture; Fisheries and Forestry (16)
- Fachlicher Dokumentenserver Paedagogik/Erziehungswissenschaften (1)
- FUNDAJ - Fundação Joaquim Nabuco (1)
- Helda - Digital Repository of University of Helsinki (13)
- Illinois Digital Environment for Access to Learning and Scholarship Repository (1)
- Indian Institute of Science - Bangalore - Índia (18)
- INSTITUTO DE PESQUISAS ENERGÉTICAS E NUCLEARES (IPEN) - Repositório Digital da Produção Técnico Científica - BibliotecaTerezine Arantes Ferra (4)
- Instituto Nacional de Saúde de Portugal (1)
- Instituto Politécnico do Porto, Portugal (3)
- Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States (1)
- Ministerio de Cultura, Spain (7)
- Open University Netherlands (1)
- Publishing Network for Geoscientific & Environmental Data (43)
- QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast (50)
- Queensland University of Technology - ePrints Archive (164)
- Repositório Científico da Universidade de Évora - Portugal (2)
- Repositório Científico do Instituto Politécnico de Lisboa - Portugal (1)
- Repositório digital da Fundação Getúlio Vargas - FGV (1)
- Repositório Institucional da Universidade de Aveiro - Portugal (4)
- Repositorio Institucional de la Universidad de Málaga (1)
- Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho" (51)
- SAPIENTIA - Universidade do Algarve - Portugal (3)
- South Carolina State Documents Depository (1)
- Universidad de Alicante (9)
- Universidad del Rosario, Colombia (2)
- Universidad Politécnica de Madrid (17)
- Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP) (1)
- Universidade Federal do Pará (1)
- Universidade Técnica de Lisboa (1)
- Universitat de Girona, Spain (3)
- Université de Lausanne, Switzerland (6)
- Université de Montréal, Canada (3)
- University of Connecticut - USA (1)
- University of Michigan (68)
- University of Queensland eSpace - Australia (26)
- WestminsterResearch - UK (3)
Resumo:
The photolytic phenanthrene-based precursors for both β-methoxycarbene and β-ethoxycarbene were synthesized with and without a deuterium label attached to the a carbon. The incorporation of this deuterium label allowed distinction between a 1, 2-H shift and a 1, 2-O shift pathway to the respective alkyl vinyl ether, without the influence of a primary kinetic isotope effect. Photolyses of these precursors gave rearrangement products of the expected β-alkoxycarbenes. In the case of β-methoxycarbene, no methyl vinyl ether was observed due to its volatility. However, the appearance of aldehyde peaks in the NMR spectra, from an apparent further rearrangement to acetaldehyde through an enol intermediate, indicated that a 1,2-H shift had occurred. Ethyl vinyl ether was isolated following the photolysis of the β-ethoxycarbene precursor. Quantification of the two pathways showed less than 2% undergoing an ethoxy shift to the ethyl vinyl ether. Yield experiments on this photolysis demonstrated a maximum yield of β-ethoxycarbene as 43%, though this decreased as the experiment continued. Computational work on the β-ethoxycarbene system indicates that the triplet scate is more stable than the singlet. In addition, the activation energy to the 1.2-H shift pathway is remarkably low and is clearly consistent with the observed overwhelming preference for this pathway in the experiment.