Results 71 to 80 of about 143,778 (251)

James Edward Huheey (1935 - 2020). En memoria de un químico fuera de lo común.

open access: yesRevista de Química, 2020
En esta pequeña nota se recuerdan las características fuera de lo comunes del autor de uno de los libros más conocidos en el área de la Química inorgánica: James E. Huheey.
Luis Ortega-San-Martin
doaj  

Shortcut to Highly Fluorescent Perylene Derivatives: From Fluoranthene Fissure‐Coupling to Late‐Stage Aromatic Extension

open access: yesChemistryEurope, EarlyView.
A two‐step shortcut for access to highly soluble, bent, and extended perylene‐based nanographene P1 from a nonperylene aromatic homologation precursor is presented. The modular, stepwise, and rational π‐extension postfunctionalization strategy allows for the tuning of the fluorescent emission properties to reach high quantum yields up to 0.78, giving ...
Lorena Capdevila   +8 more
wiley   +1 more source

Preparation of Enantioenriched Spirocyclic Scaffolds Transferring Axial Chirality from Borylalkylidenecycloalkanes

open access: yesChemistryEurope, EarlyView.
Enantiomerically enriched borylalkylidenecycloalkanes can transfer axial chirality to spirocyclic compounds with central chirality, without erosion of enantiomeric ratio. The method involves cyclopropanation, borylcyclopropanation, epoxidation, and aziridination reactions, that proceed in astereodivergent manner giving access to spirocycles with ...
Nerea Iragorri   +4 more
wiley   +1 more source

Formulación química inorgánica en educación secundaria(poquer de química)

open access: yesPulso: Revista de Educación, 2008
Uno de los principales problemas al que se enfrenta, en general, el profesorado de Ciencias Experimentales (en su labor de transmisor de conceptos) es la especificidad y dificultad que tiene, para el alumnado, la nomenclatura y epistemología utilizadas ...
José Joaquín Esteve Castell
doaj   +1 more source

Impacto do sedimento sobre o desenvolvimento do perifíton no Rio Taquari, Pantanal, MS. [PDF]

open access: yes, 2011
As macrófitas aquáticas são muito abundantes em áreas alagadas como as do Pantanal, e fornecem um vasto substrato para a microbiota, em particular para a comunidade perifítica. Foi avaliado o efeito da deposição de sedimento sobre a comunidade perifítica
OLIVEIRA, M. D. de, RODRIGUES, L.
core   +1 more source

Sequential Carboborylation–Suzuki Coupling of α,β‐Unsaturated Tosylhydrazones: A Dual CC Bond‐Forming Strategy for Molecular Diversification

open access: yesChemistryEurope, EarlyView.
Structural diversity can be generated from α,β‐unsaturated carbonyls via N‐tosylhydrazones through a one‐pot‐three‐component photochemically promoted carboborylation/allylic Suzuki sequence. The wide availability and scope regarding each of three reaction partners: carbonyls, alkylboronic acids, and aryl halides, and the functionalities available in ...
Álvaro Valdés‐Maqueda   +2 more
wiley   +1 more source

A QÚIMICA DOS ALIMENTOS E FÁRMACOS: UMA REVISÃO BIBLIOGRÁFICA MEDIADA PELA BNCC

open access: yesRevista Nova Paideia, 2020
A proposta deste estudo bibliográfico foi reconhecer exemplos das relações da Química com a qualidade de vida e o meio ambiente, na procura de consonâncias com as orientações promulgadas na atual Base Nacional Comum Curricular (BNCC) para a organização ...
Adriana Maria de Oliveira Rodrigues Melo   +2 more
doaj   +1 more source

Polymer based nanocomposites: synthetic strategies for hybrid materials [PDF]

open access: yes, 2004
Associating the well known advantages of hybrid materials to the wide potential of nanomaterials, the new and featuring class of polymer nanocomposites turned into one of the most intensively researched areas. This review highlights recent developments
Barros-Timmons, A   +2 more
core   +1 more source

Pivotal Synthesis of Tetrasubstituted Epoxides from Ketones and α‐Halo B/Si Ylides with Understanding of the Activation Modes

open access: yesChemistryEurope, EarlyView.
The preparation of diastereoselective 1,1,2,2‐tetrasubstituted borosilylepoxides is described, involving the epoxidation of ketones with α‐monohalo borylsilylmethane reagents. The nature of the ambiphilic reagent suppressed the Boron‐Wittig olefination.
Luis Tarifa   +8 more
wiley   +1 more source

Compósitos poliméricos para imageamento óptico e por raios-x em tanques de simulação hidráulica [PDF]

open access: yes, 2014
Este trabalho de pesquisa está relacionado com a investigação de novas abordagens de imageamento não-invasivo que permitam registrar a arquitetura interna de depósitos sedimentares gerados em tanques de simulação hidráulica.
Reis, Maria Helena da Silva
core  

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