1,720,992 research outputs found
Propellanes—From a Chemical Curiosity to “Explosive” Materials and Natural Products
No full textPropellanes are a unique class of compounds currently consisting of well over 10 000 representatives, all featuring two more or less inverted tetrahedral carbon atoms that are common to three bridging rings. The central single bond between the two bridgeheads is significantly weakened in the smaller entities, which leads to unusual reactivities of these structurally interesting propeller-like molecules. This Review highlights the synthesis of such propellanes and their occurrence in material sciences, natural products, and medicinal chemistry. The conversion of [1.1.1]propellane into bridgehead derivatives of bicyclo[1.1.1]pentane, including oligomers and polymers with bicyclo[1.1.1]penta-1,3-diyl repeat units, is also featured. A selection of natural products with larger propellane subunits are discussed in detail. Heteropropellanes and inorganic propellanes are also addressed. The historical background is touched in brief to show the pioneering work of David Ginsburg, Gunther Snatzke, Kenneth B. Wiberg, Gunter Szeimies, and others.DFG [BR 1750, SFB 1176]; Helmholtz associatio
13C nuclear magnetic resonance spectroscopy (13C NMR) (1-methyl-4-(5-tricyclo[8.2.2.24,7]hexadeca-1(13),4,6,10(14),11,15-hexaenyl)pyridin-1-ium;iodide)
No full textdataset for 13C nuclear magnetic resonance spectroscopy (13C NMR)
see 13C evaluatio
infrared absorption spectroscopy (IR) (1-methyl-4-(5-tricyclo[8.2.2.24,7]hexadeca-1(13),4,6,10(14),11,15-hexaenyl)pyridin-1-ium;iodide)
No full textdataset for infrared absorption spectroscopy (IR)
IR (ATR) ῡ = 3386 (vw), 3032 (vw), 2920 (vw), 2850 (vw), 2573, (vw), 2322 (vw), 2168 (vw), 2020 (vw), 1918 (vw), 1639 (vw), 1516 (vw), 1454 (vw), 1332 (vw), 1198 (vw), 1096 (vw), 949 (vw), 843 (w), 720 (vw), 642 (vw), 488 (vw) cm−1
C22H22IN
No full textThis dataset contains experimental data from a sample (1-methyl-4-(5-tricyclo[8.2.2.24,7]hexadeca-1(13),4,6,10(14),11,15-hexaenyl)pyridin-1-ium;iodide, InChI=1S/C22H22N.HI/c1-23-14-12-21(13-15-23)22-16-19-7-6-17-2-4-18(5-3-17)8-10-20(22)11-9-19;/h2-5,9,11-16H,6-8,10H2,1H3;1H/q+1;/p-1).
The datasets from the following experiments are available:
1H nuclear magnetic resonance spectroscopy (1H NMR)
13C nuclear magnetic resonance spectroscopy (13C NMR)
13C nuclear magnetic resonance spectroscopy (13C NMR)
infrared absorption spectroscopy (IR)
mass spectrometry (MS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
13C nuclear magnetic resonance spectroscopy (13C NMR) (1-methyl-4-(5-tricyclo[8.2.2.24,7]hexadeca-1(13),4,6,10(14),11,15-hexaenyl)pyridin-1-ium;iodide)
No full textdataset for 13C nuclear magnetic resonance spectroscopy (13C NMR)
13C NMR (126 MHz, D2O, ppm) δ = 144.6 (+, CH), 141.6 (2xCq.), 140.6 (Cq.), 140.0 (Cq.), 138.8 (Cq.), 137.0 (+, CH), 135.9 (+, CH), 135.8 (Cq.), 133.7 (+, CH), 133.2 (+, CH), 132.4 (+, CH), 131.8 (+, CH), 129.5 (+, 2xCH), 127.7 (+, 2xCH), 47.2 (+, CH3), 34.6 (–, CH2), 34.3 (–, CH2), 34.2 (–, CH2), 33.4 (–, CH2).
mass spectrometry (MS) (1-methyl-4-(5-tricyclo[8.2.2.24,7]hexadeca-1(13),4,6,10(14),11,15-hexaenyl)pyridin-1-ium;iodide)
No full textdataset for mass spectrometry (MS)
HRMS (ESI, C22H22N+) calc. 300.1747, found 300.1737
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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