Relevant bibliographies by topics / Isochromans

Academic literature on the topic 'Isochromans'

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Published: 20 July 2024

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Journal articles on the topic "Isochromans"

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Hamada, Shohei, Kyoko Yano, Ayano Ohshimo, Elghareeb E. Elboray, Yusuke Kobayashi, and Takumi Furuta. "Oxidative C–N Bond Formation of Isochromans Using an Electronically Tuned Nitroxyl Radical as Catalyst." SynOpen 08, no. 02 (May 2024): 125–29. http://dx.doi.org/10.1055/s-0040-1720118.

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AbstractThe cross-dehydrogenative coupling between isochromans and nucleophiles using an electronically tuned nitroxyl radical catalyst, which effectively promotes the oxidation of benzylic ethers, has been investigated. Using sulfonamides as a nucleophile, modification of isochromans via oxidative C–N bond formation has been achieved at ambient temperature.
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Liu, Shiyao, Kazunari Nakajima, and Yoshiaki Nishibayashi. "Copper-catalysed enantioselective intramolecular etherification of propargylic esters: synthetic approach to chiral isochromans." RSC Advances 9, no. 33 (2019): 18918–22. http://dx.doi.org/10.1039/c9ra03880a.

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Trefiletti, Giuliana, Anna Rita Togna, Valentina Latina, Carolina Marra, Marcella Guiso, and Giuseppina I. Togna. "1-Phenyl-6,7-dihydroxy-isochroman suppresses lipopolysaccharide-induced pro-inflammatory mediator production in human monocytes." British Journal of Nutrition 106, no. 1 (January 27, 2011): 33–36. http://dx.doi.org/10.1017/s0007114510005763.

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Extra-virgin olive oil is an integral ingredient of the Mediterranean diet, and it has been suggested that its high consumption has beneficial effects on human health. Its protective effect, in particular against the development of CVD, has been related not only to the high content of oleic acid, but also to the antioxidant and anti-inflammatory properties of polyphenols. In order to verify the anti-inflammatory and anti-atherogenic properties of hydroxy-isochromans, a class of ortho-diphenols present in extra-virgin olive oil, we investigated the potential ability of 1-phenyl-6,7-dihydroxy-isochroman (L137) to modulate the production of key inflammatory mediators by human monocytes, by evaluating its in vitro effects on prostanoid (thromboxane A2 and PGE2) and cytokine (TNF-α) production. Its effect on the protein expression of the inducible form of cyclo-oxygenase-2 (COX-2), a pro-inflammatory enzyme responsible for elevated prostanoid levels, was also explored. The results showed that L137 significantly inhibited both prostanoid and TNF-α production in lipopolysaccharide-primed human monocytes in a dose-dependent manner, by inhibiting the COX activity of COX-2. We also demonstrated that the effects of the isochroman are mediated, at least partly, through the suppression of NF-κB activation leading to the down-regulation of the synthesis of COX-2.
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UNTERHALT, B., and R. JOESTINGMEIER. "ChemInform Abstract: New Substituted Isochromans." ChemInform 28, no. 1 (August 4, 2010): no. http://dx.doi.org/10.1002/chin.199701169.

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Verma, Ashish Kumar, Ande Chennaiah, Sateesh Dubbu, and Yashwant D. Vankar. "Stereoselective synthesis of sugar-fused (or 1,2-annulated) isochromans and isochromanones by using oxa-Pictet–Spengler reaction." Organic & Biomolecular Chemistry 16, no. 37 (2018): 8258–62. http://dx.doi.org/10.1039/c8ob01698d.

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Thatikonda, Thanusha, Siddharth K. Deepake, Pawan Kumar, and Utpal Das. "α-Angelica lactone catalyzed oxidation of benzylic sp3 C–H bonds of isochromans and phthalans." Organic & Biomolecular Chemistry 18, no. 21 (2020): 4046–50. http://dx.doi.org/10.1039/d0ob00729c.

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Nickerson, Leslie A., Benjamin D. Bergstrom, Mingchun Gao, Yuan-Shin Shiue, Croix J. Laconsay, Matthew R. Culberson, Walker A. Knauss, James C. Fettinger, Dean J. Tantillo, and Jared T. Shaw. "Correction: Enantioselective synthesis of isochromans and tetrahydroisoquinolines by C–H insertion of donor/donor carbenes." Chemical Science 11, no. 19 (2020): 5113. http://dx.doi.org/10.1039/d0sc90081h.

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Correction for ‘Enantioselective synthesis of isochromans and tetrahydroisoquinolines by C–H insertion of donor/donor carbenes’ by Leslie A. Nickerson et al., Chem. Sci., 2020, 11, 494–498, DOI: 10.1039/C9SC05111B.
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Unterhalt, B., and U. Heppert. "ChemInform Abstract: Isochromans Related to Fluoxetin." ChemInform 32, no. 38 (May 24, 2010): no. http://dx.doi.org/10.1002/chin.200138108.

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Zhu, Zhengbo, Alafate Adili, Chenfei Zhao, and Daniel Seidel. "Catalytic Enantioselective Approaches to the oxa-Pictet–Spengler Cyclization and Other 3,6-Dihydropyran-Forming Reactions." SynOpen 03, no. 03 (July 2019): 77–90. http://dx.doi.org/10.1055/s-0039-1690686.

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This Short Review provides an analysis of the state-of-the-art in catalytic enantioselective oxa-Pictet–Spengler cyclizations. Also discussed are other catalytic reactions providing access to enantio­enriched isochromans and tetrahydropyrano[3,4-b]indoles. Context is provided and remaining challenges are highlighted.
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Yang, Guoping, Ke Li, Kai Zeng, Yijin Li, Tao Yu, and Yufeng Liu. "Heteropolyacid ionic liquid heterogeneously catalyzed synthesis of isochromans via oxa-Pictet–Spengler cyclization in dimethyl carbonate." RSC Advances 11, no. 18 (2021): 10610–14. http://dx.doi.org/10.1039/d1ra01004b.

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An efficient heterogeneous and green catalyst [HEMTH]H2[PMo12O40] was prepared to catalysis the oxa-Pictet–Spengler cyclization of arylethanols and aldehydes to afford isochromans with excellent yields using dimethyl carbonate as a green solvent.
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Dissertations / Theses on the topic "Isochromans"

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Joll, Cynthia Ann. "The asymmetric synthesis of isochromans related to the aphid pigments." Thesis, Joll, Cynthia Ann (1995) The asymmetric synthesis of isochromans related to the aphid pigments. PhD thesis, Murdoch University, 1995. https://researchrepository.murdoch.edu.au/id/eprint/51655/.

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Many of the naturally occurring benzoisochromanquinones exhibit notable biological activity, being potential antibiotics or antineoplastic agents. The synthetic work described in this thesis is directed towards the asymmetric synthesis of Quinone A 2, Quinone A 3 and Deoxyquinone A 4, three derivatives of the naturally occurring benzoisochromanquinone aphid pigments, protoaphin-fb, protoaphin-sl and deoxyprotoaphin, respectively. In the first chapter, a comprehensive review of a category of benzoisochromanquinone natural products related to the aphid pigment derivatives is presented, highlighting their structures, occurrence and biological activities. This is followed by a discussion of the isolation and structural elucidation of the aphid pigments themselves. The racemic synthesis of the aphid pigment derivatives 2, 3 and 4, and the asymmetric syntheses of several related naturally occurring benzoisochromanquinones are reviewed in the latter part of the chapter. An approach to the first chiral synthesis of Quinone A 2, Quinone A' 3 and Deoxyquinone A 4, through a key intermolecular reaction between a metal phenolate and a chiral aldehyde, is detailed in Chapter Two. It was first necessary to prepare an aromatic compound which is a suitable precursor to the benzyne 189. The assembly of two different precursors is described, and the yields of their respective conversions to the intermediate benzyne 189 and in situ cycloaddition reaction with 2-methoxyfuran compared. Model studies of the key intermolecular reaction, using 4,5,7-trimethoxynaphthalene-1-ol and the 1-ethoxyethyl ether of (2S)-2-hydroxypropanal, are then presented. This reaction was highly diastereoselective and this was controlled by the choice of the metal. Thus, the product of addition of the titanium phenolate differed from that of the magnesium phenolate only at the newly created chiral centre. Chapter Three deals with the application of the reaction between metal phenolates and chiral aldehydes to intramolecular processes. Firstly, commercially available 2,5-dihydroxyacetophenone was transformed into the differentially protected 5-benzyloxy-2-methoxyacetophenone. This was followed by extension of the side chain by formation of an ether with (S)-ethyl lactate. Ultimately, two diastereomeric optically-pure phenols, each bearing an aldehydic side chain derived from (S)-ethyl lactate, were prepared. These were each treated separately with both titanium tetraisopropoxide and ethyl magnesium bromide and the products of the four reactions examined in detail. In the case of the bromomagnesium phenolates, the yields of cyclized products were poor, and for one of these diastereomeric phenolates the stereoselectivity of cyclization was only average. For the titanium phenolates, high yields of products of intramolecular cyclization were obtained. The diastereoselectivity of the cyclization reaction was only 3:1 in one case, but in the other, which produced the required benzopyran analogous to Quinone A, the cyclization was completely diastereoselective. Thus, the first chiral synthesis of a benzopyranquinone having the same absolute stereochemistry as the enantiomer of Quinone A, i.e., quinone 234, is presented.
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Muller, Cyprien. "Supramolecular catalysis and vibrational strong coupling : how to influence chemical reactivity ?" Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAF014.

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Comment peut-on influencer la réactivité chimique ? Dans ce travail de thèse, j’ai tâché de répondre à cette question en explorant la frontière entre la chimie et la physique. Dans un premier temps, en tirant avantage du solvant 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) qui permet souvent une réactivité exotique, qui peut être attribuée à ses exceptionnelles propriétés physiques. Ces dernières font de HFIP une véritable matrice supramoléculaire, qui nous a permis le développement d’une nouvelle méthode pour la synthèse d’isochromanes fonctionnalisés. Ce faisant, une généralité et une simplicité opératoire inédites pour la synthèse de ce motif important furent atteintes. Dans un second temps, j’ai exploré la capacité de l’hybridation lumière-matière, accessible grâce au couplage fort vibrationnel (CFV) de modifier la cinétique de certaines réactions chimiques. Ainsi, en plaçant entre deux miroirs différents réactifs, j’ai étudié l’impact du CFV sur la nucléophilicité ainsi que sur la réactivité Diels-Alder
How can we influence chemical reactivity? Throughout this thesis, I attempted to answer this question by exploring the frontier between chemistry and physics.First, I took advantage of solvent 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) which often unlocks exotic reactivity that can be explained by its extraordinary physical properties. These properties make of HFIP a veritable supramolecular matrix, which allowed the development of a new method for the synthesis of densely functionalized isochromans. This method displayed unprecedented generality, simplicity, and practicality on the way to this pharmacologically important motif.Second, I investigated how light-matter hybridization, accessed through Vibrational Strong Coupling (VSC) could alter the kinetics of some chemical reactions. In practice, by placing different reactants between two mirrors, I studied the impact of VSC on nucleophilicity, as well as on Diels-Alder reactivity
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Fronert, Jeanne Katrin [Verfasser]. "Organokatalytische asymmetrische Synthesen von Dihydrobenzofuranen und Isochroman-1-onen / Jeanne Katrin Fronert." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1080490825/34.

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Habert, Loïc. "Synthèse et étude de la réactivité d'ynamides. Application pour la synthèse de composés azotés d'intérêts biologiques." Thesis, Orléans, 2018. http://www.theses.fr/2018ORLE2065.

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Compte tenu de l’omniprésence des hétérocycles azotés dans de nombreux produits bioactifs, le développement de méthodologies efficaces pour y accéder et les fonctionnaliser constitue un objectif majeur en chimie. Les ynamides représentent des châssis moléculaires intéressants permettant l’accès à divers hétérocycles azotés ou oxygénés. Notre objectif a consisté à étudier la réactivité des ynamides afin de synthétiser des petites bibliothèques de molécules d’intérêt biologiques à partir d’un squelette commun. La mise en oeuvre de méthodologie innovante a été nécessaire en s’attachant à respecter les principes suivants : économie d’atomes, processus catalytique, synthèse en peu d’étapes avec un contrôle de la chimio- et de la régiosélectivité.Dans un premier temps, nous avons étudié la réaction de carbozincation d’ynamides permettant l’accès à divers énamides diversement substitués. Par la suite, l’étude de la réaction de cycloisomérisation des yne-carbamates nous a permis le développement de deux méthodologies avec des sels de zinc (II) ou de rhodium (II) permettant l’accès aux noyaux oxazolones et à ses dérivés. Nos projets se sont ensuite orientés vers l’étude de l’intermédiaire ion cétèniminium, accessible via une activation acide de l’ynamide. Le développement de deux méthodes d’accès aux noyaux 3-amino-isocoumarines a pu être réalisé via l’ajout d’acide de Lewis ou de Brønsted ou via une cyclisation électrophile. Pour finir, un processus tandem de couplage/cycloisomérisation/addition nucléophile a été mis en place afin d’accéder aux noyaux 1H-isochromène
The constant demand for original small molecule collections with promesing therapeutic potential have required the development of new and efficient synthetic methods. Given the nitrogen ubiquity in nature and in life sciences, the aim of this work is the development of original heterocyclic building blocks, originated from the functionalization of ynamide frameworks. Our goal was to study the reactivity of ynamides in order to synthesize from a common skeleton small library of nitrogen or oxygen compounds with biological relevance. The implementation of a new innovative methodology has been necessary, while trying to adhere to the following principles: atom economy, catalytic reaction, fast synthesis in minimal steps, and control of chemo- and regioselectivity.Firstly, we studied the carbozincation reaction of ynamides allowing access to several substituted enamides. Subsequently, cycloisomerization reaction of yne-carbamates has allowed us the development of two novels methodologies using zinc (II) or rhodium (II) salts, which provide access to oxazolone scaffolds. Our research has been studying the keteniminium ion intermediates accessible via an acid activation of ynamide. The development of two methods for the 3-amino-isocoumarin core was achieved via addition of Lewis or Brønsted acid or via electrophilic cyclization. Finally, a tandem coupling / cycloisomerization / nucleophilic addition reaction was carried out in order to prepare 1H-isochromene
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Lewis, Shane E. "Development of a Three Step Cascade Synthesis of 2,4-Dihydro-1H-benzo[f]isochromenes." W&M ScholarWorks, 2015. https://scholarworks.wm.edu/etd/1539626965.

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Coelho, Paulo. "Etude de la diastereoselectivite des reactions intramoleculaires de composes presentant un atome de silicium chiral. Synthese de derives de 4-silatetrahydro-isochroman-1-ones, de 4-sila-2h-isoquinolein-1-ones et de silacycloalcanes." Paris 11, 1995. http://www.theses.fr/1995PA112069.

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Divers silatrienes et alcenyl(bromomethyl)silanes presentant un atome de silicium chiral ont ete synthetises en 4 a 6 etapes a partir de chlorosilanes commerciaux avec des rendements satisfaisants afin d'etudier la selectivite de reactions de diels-alder intramoleculaires et de cyclisations radicalaires intramoleculaires. Des 4-sila-4a,7,8,8a-tetrahydroisochroman-1-ones et des 4-sila-3,4,4a,7,8,8a-hexahydro-2h-isoquinolein-1-ones ont ete preparees diastereoselectivement par reaction de diels-alder intramoleculaire des acrylates, methacrylates et monomethylfumarates de 2-methyl-2-silahexa-3,5-dienyle et des n-benzyl-n-(buta-1,3-dienylsilylmethyl)acrylamides. C'est la cycloaddition de l'acrylate de 2-(2-methoxyphenyl)-2-methyl-2-silahexa-3,5-dienyle catalysee par etalcl#2 a temperature ambiante qui presente la meilleure selectivite: l'un des diastereoisomeres constitue 90% du melange des quatre silatetrahydroisochromanones isole avec un rendement de 74%. Des 4-sila-3,4,4a,5-tetrahydro-2h-isoquinolein-1-ones ont ete preparees diastereoselectivement par reaction de diels-alder a demande electronique inverse des n-benzyl-n-(vinylsilylmethyl)-2-pyranone-6-carboxamides, suivie d'elimination de co#2 par reaction de retro diels-alder. La meilleure selectivite (rapport des diastereoisomeres: 80/20) a ete obtenue avec le compose presentant les groupes cyclohexyle et methyle sur l'atome de silicium. La 4-cyclohexyl-4-methyl-4-sila-3,4,4a,5,6,8a-hexahydro-2h-isoquinolein-1-one-6,8a-carbolactone intermediaire dans cette reaction a pu etre isolee. Le traitement des alcenyl(bromomethyl)silanes par l'hydrure de tributyletain permet de preparer selectivement et avec de bons rendements des silacyclopentanes, des silacyclohexanes et des silacycloheptanes
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Mariaule, Gaëlle. "Accès original aux hétérocycles par la catalyse organométallique : développement de nouveaux inhibiteurs de kinases." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05P612/document.

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Cette thèse est composée de deux parties distinctes ayant comme thématique commune, la synthèse d’hétérocycles via la catalyse organométallique.Nous nous sommes intéressés, dans un premier temps, à une voie de synthèse permettant un accès rapide au squelette tétrahydrocyclopenta[c]acridine. Ces composés polyfonctionnalisés sont obtenus très efficacement en seulement trois étapes dans des conditions particulièrement douces. L’étape clé de cette synthèse est une réaction de Pauson-Khand intramoléculaire catalysée au cobalt. Certains composés issus de la famille des tétrahydrocyclopenta[c]acridines présentent une activité d’inhibition sélective envers les kinases dépendantes des cyclines (CDKs), et plus particulièrement la CDK2. Un composé chef de file est identifié, puis grâce aux données de co-Cristallisation avec CDK2 et de modélisation moléculaire, suivi de l’étude des relations structure-Activité, la conception rationnelle d’une deuxième génération de molécules est rendue possible. Le composé le plus avancé présente une CI50 de 300 nM envers CDK2/cyclin A et un excellent profil de stabilité métabolique.Dans un deuxième temps, nous avons étudié et développé une réaction tandem d’addition/cyclisation catalysée par l’argent, avec des nucléophiles carbonés sur des substrats ortho-Alcynylbenzaldéhydes. La stratégie de synthèse conduit à des dérivés 1H-Isochromènes par création de deux nouvelles liaisons (C-C et C-O). Une étude approfondie de la réaction tandem nous a permis d’obtenir une large gamme de dérivés d’isochromènes en mettant en évidence l’influence de différents substituants, portés par le groupement alcyne ou le substrat, ainsi que l’utilisation de différents nucléophiles carbonés (alcynes, aromatiques, hétéroaromatiques). Les limitations de la réaction tandem ont également pu être identifiées
My thesis proJect is organized around two main topics having in common organometallic chemistry and the synthesis of heterocycles.Firstly, we were interested in a methodology for the synthesis of tetrahydrocyclopenta[c]acridines. These compounds are synthesized in three steps from various quinolines. The key step is a cobalt-Catalyzed intramolecular Pauson-Khand reaction. Some compounds of this family exhibit selective Cyclin Dependent Kinases (CDKs) inhibition, particulary against CDK2, in the submicromolar range. A hit compound has been identified, and then using data from co-Crystallization with CDK2 and molecular modeling, followed by the study of structure-Activity relationships, the rational design of a second generation of molecules has been investigated. The most advanced compound has an IC50 of 300 nM against CDK2/cyclin A with an excellent metabolic profile. In the second axis of research, we have studied and developed a new silver-Catalyzed tandem addition/cyclization reaction with carbon nucleophiles. The systems studied are (hetero)aromatics compounds having an aldehyde group and in ortho-Position an alkynyl group. The synthetic strategy leads to 1H-Isochromene derivatives by creating two new bonds. A thorough study of the tandem reaction allowed us to obtain a wide range of isochromene derivatives, highlighting the influence of different substituents carried by the alkyne group or on the (hetero)aromatic substrates; and also to investigate the use of different carbon nucleophiles (alkynes, aromatics and heteroaromatics). The limitations of the tandem reaction have also been identified
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Gorgoi, Mihaela. "Electronic Properties of Phthalocyanines Deposited on H-Si(111)." Doctoral thesis, Universitätsbibliothek Chemnitz, 2007. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200700213.

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Im Rahmen dieser Arbeit wurden vier Phthalocyanine untersucht: Metallfreies-Phthalocyanin (H2Pc), Kupferphthalocyanin (CuPc) und Fluor-substituiertes Phthalocyanin (F4CuPc und F16CuPc). Das Ziel dieser Arbeit ist die Charakterisierung der elektronischen und chemischen Eigenschaften der Grenzflächen zwischen diesen Molekülen und Silizium. Die Moleküle wurden durch organische Molekularstrahldeposition (OMBD) im Ultrahochvakuum auf wasserstoffpassivierte Si(111)-Substrate aufgedampft. Oberflächensensitive Messmethoden wie Photoemissionsspektroskopie (PES), Bremsstrahlung Isochromaten Spektroskopie (BIS oder IPES - Inverse Photoemissionsspektroskopie) und Spektroskopie der Röntgen-Absorptions-Feinstruktur (NEXAFS – Near Edge X-Ray Absorption Fine Structure) wurden zur Charakterisierung eingesetzt. Um eine Zuordnung der verschiedenen Komponenten in PES und IPES zu ermöglichen, wurden Methoden der Dichtefunktionaltheorie zur theoretischen Berechnung eingesetzt. Die Energieniveauanpassung an der Grenzfläche zwischen der organischen Schicht und der H-Si-Grenzfläche, sowie die Transportbandlücke von H2Pc, CuPc, F4CuPc und F16CuPc wurden mit Hilfe von PES und IPES bestimmt. Die NEXAFS-Messungen ermöglichten eine genaue Bestimmung der Molekülorientierung relativ zum Substrat. Die Auswertung der Daten zeigte unterschiedliche Molekülorientierungen in dünnen und dicken Filmen. Diese Änderungen wurden mit dem bandverbiegungsähnlichen Verlauf der HOMO-und LUMO-Positionen in Verbindung gebracht. Zusätzlich zu diesem Verhalten wiesen die Grenzflächen auch einen Grenzflächendipol auf, welcher durch die unterschiedlichen Austrittsarbeiten der Kontaktmaterialien hervorgerufen wird. Der Einfluss des Grads der Flouridierung wird durch eine ähnlichen Zunahme der Elektronenaffinität (EA), der Austrittsarbeit (WF) und der Ionisierungsenergie (IE) bestätigt. Die elektronischen Eigenschaften von Metall/organische-Schicht-Grenzflächen und von organischen Schichten unter Sauerstoffeinfluss wurden mit Hilfe von PES und IPES untersucht. Die Ag/Pc Grenzflächen zeigten eine Mischung aus HOMO-LUMO-Verschiebungen und Grenzflächendipolbildung. An den Ag/H2Pc- und Ag/F16CuPc- Grenzflächen wurde ein Ladungstransferkomplex gebildet. Auf der CuPc-Schicht physisorbiert das Ag lediglich und im Fall von F4CuPc wird Ladung zu Ag transferiert, wobei eine andauernde n-Typ-Dotierung an der Grenzfläche erzeugt wird. In Analogie zum Fall der Pc/H-Si Grenzfläche wiesen die Dipole, die hier gefunden wurden, eine lineare Abhängigkeit von EA, WF und IE auf und können durch die Differenz zwischen den Austrittsarbeiten vorausgesagt werden. Das Verhalten der dicken organischen Schichten unter Sauerstoffeinfluss kann in zwei Gruppen eingeteilt werden. Eine Gruppe, bestehend aus H2Pc und F4CuPc, wies nur schwache Wechselwirkung auf und der Sauerstoff physisorbiert auf der Pc-Schicht. Die beiden anderen Moleküle, CuPc und F16CuPc konnten einer Gruppe starker Wechselwirkung zugeordnet werden. CuPc bildet einen Ladungstransferkomplex mit Sauerstoff und auf F16CuPc wird eine polarisierte Schicht gebildet
In the context of this work four Phthalocyanine were studied: Metal-free Phthalocyanine (H2Pc), Copper Phthalocyanine (CuPc) and fluorine-substituted Phthalocyanine (F4CuPc and F16CuPc). The goal of this work is the electronic and chemical characteristics of the interfaces. The molecules were deposited by organic molecular beam deposition (OMBD) in the ultra high vacuum on hydrogen-passivated Si(111)-Substrate. Surface sensitive techniques such as photoemission spectroscopy (PES), bremsstrahlung isochromate spectroscopy (BIS or IPES - inverse photoemission spectroscopy) and near edge X-ray absorption fine structure spectroscopy (NEXAFS) were used for characterisation. Theoretical computations by density functional theory methods were employed, in order to assign different components in PES and IPES. The energy level alignment at the organic/H-Si interface, as well as the transport gap of H2Pc, CuPc, F4CuPc and F16CuPc were determined by PES and IPES. The NEXAFS measurements determine the exact molecular orientation with respect to the substrate. The evaluation of the data showed different molecular orientation in the thin and thick films. This change was correlated with the band bending like behaviours that emerged at these interfaces. In addition to the band bending like behaviour, the interfaces show also an interface dipole which is driven by the work function difference between the contact materials. The influence of the degree of fluorination is confirmed in the similar increase of the EA, WF and IE. The electronic properties of metal/organic layer interfaces and of organic layer under oxygen influence were examined by PES and IPES. The Ag/Pc interfaces show a mixture of HOMO-LUMO shifts and interface dipole formation. A charge transfer complex is formed in the case of Ag/H2Pc and Ag/F16CuPc interfaces. Ag is physisorbed atop the CuPc. Charge transfers from F4CuPc to Ag creating a continuous n-type doping at the interface. Similar to the Pc/H-Si interfaces the interface dipoles found here show a linear dependence on the EA, WF and IE and can be predicted by the difference in the work functions. The data evaluation of oxygen exposed thick films determined two groups of behaviours. The weak interaction group is represented by H2Pc and F4CuPc, Pcs on which oxygen is physisorbed. The strong interaction group contains the other two molecules CuPc and F16CuPc. CuPc forms a charge transfer complex with oxygen and on top of F16CuPc a polarized layer is formed
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Gina, Ervin. "Implementation and Optimization of an Inverse Photoemission Spectroscopy Setup." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4050.

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Inverse photoemission spectroscopy (IPES) is utilized for determining the unoccupied electron states of materials. It is a complementary technique to the widely used photoemission spectroscopy (PES) as it analyzes what PES cannot, the states above the Fermi energy. This method is essential to investigating the structure of a solid and its states. IPES has a broad range of uses and is only recently being utilized. This thesis describes the setup, calibration and operation of an IPES experiment. The IPES setup consists of an electron gun which emits electrons towards a sample, where photons are released, which are measured in isochromat mode via a photon detector of a set energy bandwidth. By varying the electron energy at the source, a spectrum of the unoccupied density of states can be obtained. Since IPES is not commonly commercially available the design consists of many custom made components. The photon detector operates as a bandpass filter with a mixture of acetone/argon and a CaF2 window setting the cutoff energies. The counter electronics consist of a pre-amplifier, amplifier and analyzer to detect the count rate at each energy level above the Fermi energy. Along with designing the hardware components, a Labview program was written to capture and log the data for further analysis. The software features several operating modes including automated scanning which allows the user to enter the desired scan parameters and the program will scan the sample accordingly. Also implemented in the program is the control of various external components such as the electron gun and high voltage power supply. The new setup was tested for different gas mixtures and an optimum ratio was determined. Subsequently, IPES scans of several sample materials were performed for testing and optimization. A scan of Au was utilized for the determination of the Fermi edge energy and for comparison to literature spectra. The Fermi edge energy was then used in a measurement of indium tin oxide (ITO) determining the conduction band onset. This allowed the determination of the "transfer gap" of ITO. Future experiments will allow further application of IPES on materials and interfaces where characterization of their electronic structure is desired.
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Senanayake, Badra Sriyani. "Approaches to natural isochromans by isomerisation of aryldioxolanes." Phd thesis, 1992. http://hdl.handle.net/1885/138963.

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Book chapters on the topic "Isochromans"

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Lavine, Barry K., and Collin White. "Odor-Structure Relationship Studies of Indan, Tetralin, and Isochroman Musks." In ACS Symposium Series, 333–59. Washington, DC: American Chemical Society, 2015. http://dx.doi.org/10.1021/bk-2015-1191.ch023.

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Fuggle, John C. "Bremsstrahlung isochromat spectroscopy (BIS or High-Energy Inverse Photoemission)." In Topics in Applied Physics, 307–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/3540541624_20.

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Fauszt, I., A. Fehér, Gy Horváth, A. Juhász, E. Széll, and S. Bajusz. "Facile synthesis of 1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid, a constrained phenylglycine and its oxa analog, isochromane-1-carboxylic acid." In Peptides 1994, 678–79. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-1468-4_311.

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Fortuné, Danielle, and Bruno Deshoullières. "Modelling of Sliding Wave Phenomenon, on the Contact Boundary between Two Bodies, by the Boundary Integral Element Method: Numerical Visualization of Isochroms." In Contact Mechanics, 267–70. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-1983-6_36.

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"Olive Oil Hydroxy-Isochromans." In Olive Oil, 207–14. CRC Press, 2008. http://dx.doi.org/10.1201/9781420059946-13.

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Guiso, Marcella, Giuliana Trefiletti, and Giuseppina Togna. "Olive Oil Hydroxy-Isochromans." In Olive Oil, 193–200. CRC Press, 2008. http://dx.doi.org/10.1201/9781420059946.ch9.

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Nógrádi, M. "By Oxidative Fragmentation of 1-2-Benzopyrans (Isochromans)." In Six-Membered Hetarenes with One Chalcogen, 1. Georg Thieme Verlag KG, 2003. http://dx.doi.org/10.1055/sos-sd-014-00146.

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Freeman, R. "Spin choreography." In Pulsed Magnetic Resonance: NMR, ESR, and Optics, 219–41. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780198539629.003.0010.

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Abstract Very soon after the initial discovery of nuclear magnetic resonance, E. L. Hahn performed an experiment that, in conceptual originality and elegance, transcended all that had preceded it-the spin echo experiment [1]. Here was an idea to inspire the young scientists reading about NMR for the first time. Not only could oneworkwith these strange new entities called spins, but alsomanipulatethem like a conjuror with a pack of cards. In its original form, experiment was conceptually easier to follow, resembling the opening and closing of a ‘fan’ of vectors confined to the transverse(x-y)plane of the rotating frame. Note that the description of the conventional continuous wave NMR experiments of the time scarcely required this level of sophistication, relying on the steady state solutions of the Bloch equations. To understand spin echoes, one was forced to come to grips with homogeneous and inhomogeneous line broadening, transformation into the rotating frame of reference, and the concept of ‘spin isochromats’. This was a term coined by Abragam [3]. The sample is considered to be made up of a mosaic of volume elements, each small enough that the variation of the applied field intensity across that element could be neglected, but with neighbouring elements in slightly different applied fields due to the spatial inhomogeneity. Each element has a nuclear magnetization with a characteristic precession frequency; this is an isochromat. The total sample magnetization is the resultant of all these isochromatic magnetization vectors. Because the isochromats have different intrinsic frequencies this resultant can change as individual isochromats fan out or come back into alignment. This has proved a valuable idea for describing spin echo experiments.
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Riviere, J. C. "Electron excitation: inverse photoemission spectroscopy (IPES)." In Surface Analytical Techniques, 193–209. Oxford University PressOxford, 1990. http://dx.doi.org/10.1093/oso/9780198513704.003.0007.

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Abstract The technique of Inverse Photoemission Spectroscopy, or IPES, was, and still is by a few workers, called Bremsstrahlung Isochromat Spectroscopy (BIS}. Both names give a clue to the mode of operation, which in principle, and to a certain extent in practice, is quite simple. The surface is irradiated with monoenergetic electrons and the bremsstrahlung photons so created are detected at a fixed wavelength, while the energy of the primary electrons is scanned. If no angular resolution is required in the measurements, then it is adequate to provide primary electrons simply from a hot filament in front of the surface being studied. However, much additional information can be obtained from angularly resolved studies, which require a focused beam, and in any case most workers already have available on their equipment one or other of the various designs of electron gun described under Section 3.2.1.
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Hillebrecht, F. U., and M. Campagna. "Chapter 70 Bremsstrahlung isochromat spectroscopy of alloys and mixed valent compounds." In High Energy Spectroscopy, 425–51. Elsevier, 1987. http://dx.doi.org/10.1016/s0168-1273(87)10012-8.

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Conference papers on the topic "Isochromans"

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"SEMI-EXPERIMENTAL INVESTIGATION OF COMPOUND 1H,3HBENZO[DE]ISOCHROMENE-1,3-DIONE." In 2nd International Conference on Contemporary Academic Research ICCAR 2023. All Sciences Academy, 2023. http://dx.doi.org/10.59287/as-proceedings.191.

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C.T., Samlan, Dinesh N. Naik, and Nirmal K. Viswanathan. "Separating Isogyres and Isochromates of a Uniaxial Crystal using Fourier Fringe Analysis." In International Conference on Fibre Optics and Photonics. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/photonics.2016.th3a.4.

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Jackson, Warren B. "Electronic Structure of Crystalline and Amorphous Semiconductors and Heterojunctions Using Bremsstrohlung Isochromat Spectroscopy." In 1986 International Conference on Solid State Devices and Materials. The Japan Society of Applied Physics, 1986. http://dx.doi.org/10.7567/ssdm.1986.d-11-1.

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Reports on the topic "Isochromans"

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Tobin, J., M. Butterfield, N. Teslich, A. Bliss, B. Chung, J. Gross, A. McMahan, and A. Schwartz. Nano-focused Bremstrahlung Isochromat Spectroscopy (nBIS) Determination of the Unoccupied Electronic Structure of Pu. Office of Scientific and Technical Information (OSTI), December 2006. http://dx.doi.org/10.2172/898443.

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