Search results for "Phanes"
showing 10 items of 29 documents
Adamantan als Baustein neuer Araliphane Synthese, Spektroskopie und Kristallstrukturen
1991
Adamantane as a Building Block of New Araliphanes – Synthesis, Spectroscopy, and Crystal Structures Exchange of benzene units for aliphatic building blocks in cyclophanes leads to new molecules of the “araliphane” type. With adamantane the araliphanes 2 – 4 are synthesized. Their stereochemical behavior as shown by NMR studies and X-ray crystallographic analyses differs significantly from that of their aromatic counterparts. The signals of the intraannular adamantane hydrogens are strongly shifted upfield up to δ=– 2.18 (in 2). 4 is obtained as a racemic mixture of enantiomers (in the crystalline state) and shows a boat-like deformation of the benzene moiety.
Las islas: ¿comedia aristofánica o comedia media?
2012
Este artículo revisa la cuestión de la autenticidad de la comed ia fragmentaria de Aristófanes “Las islas”. Pese a las dudas surgidas en la antigü edad y aún hoy en día por parte de los estudiosos modernos, las conclusiones son claras: “Las isla s” es una comedia de Aristófanes. Esto aparece confi rmado por su interacción con otras piezas aristofánicas, su le ngua, su estilo y su espíritu, completamente dentro de las coordenadas de Arist ófanes y de la comedia griega antigua. This paper reviews the Aristophanic authenticity of the fragmen tary comedy “Islands”. Despite the doubts raised in antiquity and today by modern scho lars, conclusions are fi rm: “Islands” is an Aristophanic comedy. T…
Involvement of Bax and Bcl-2 in induction of apoptosis by essential oils of three Lebanese Salvia species in human prostate cancer cells
2018
Prostate cancer is one of the most common forms of cancer in men, and research to find more effective and less toxic drugs has become necessary. In the frame of our ongoing program on traditionally used Salvia species from the Mediterranean Area, here we report the biological activities of Salvia aurea, S. judaica and S. viscosa essential oils against human prostate cancer cells (DU-145). The cell viability was measured by 3(4,5-dimethyl-thiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) test and lactate dehydrogenase (LDH) release was used to quantify necrosis cell death. Genomic DNA, caspase-3 activity, expression of cleaved caspase-9, B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X (Ba…
Relaxed but highly compact diansa metallacyclophanes.
2011
A series of monoansa [μ-1,1′-PR-3,3′-Co(1,2-C2B9H10)2]− and diansa [8,8′-μ-(1″,2″-benzene)-μ-1,1′-PR-3,3′-Co(1,2-C2B9H9)2]− (R = Ph, tBu) cobaltabisdicarbollidephanes have been synthesized, characterized and studied by NMR, MALDI-TOF-MS, UV-visible spectroscopy, cyclic voltammetry, and DFT calculations. Single crystal X-ray diffraction revealed a highly relaxed structure characterized by the title angle α of 3.8° ([7]−), this being the smallest angle α for a metallacyclophane. In such compounds, the metal-to-phosphorus distance is less than the sum of their van der Waals radii. The availability of a phosphorus lone pair causes an electron delocalization through the metal, as shown by the ab…
Brief an Garlieb H. Merkel
1799
Ms. 930a, Nr. 8, Bl. 22r-23v Böttiger, Karl August. Brief an Garlieb H. Merkel, Weimar, d[en] 13. November 1797 Autora rokraksts / Autograph, vācu, angļu un latīņu val. / Deutsch, Englisch und Latein [4] lpp. / S. Attēlu numuri / Bildnummern: 930a-008-1 – 930a-008-4 Der Verfasser nennt in diesem inhaltsreichen Brief zahlreiche Namen und hält nicht nur die Verbindung mit Merkel, die aus dessen erstem Aufenthalt in Weimar resultierte, aufrecht, sondern gibt ihm weitere Hinweise und Empfehlung für seinen weiteren Aufenthalt in Dänemark. So rät er zur Übersetzung dreier Romane aus dem Englischen, darunter Jane Wests „A gossip's story“ (London 1796). Ferner bittet der Verfasser Merkel um Gefälli…
Molecular Ribbons Containing Pyridine Rings
1996
The first synthesis of the ribbon-like compounds 6–10 is described. The new building block diethyl 2,6-bis(bromomethyl)pyridine-3,5-dicarboxylate 1 was prepared and characterized. Single-crystal X-ray structure analyses indicate that these ribbon-like molecules arrange in a folded conformation, with the pyridine and benzene units being folded in a face-to-face manner, and the tosyl units of 8–10 pointing outwards. The “intramolecular self-assembly” (folding) of these molecular ribbons is primarily attributable to the energetically more favourable syn conformation of both the [3.3]metacyclophanes and the pyridinophanes.
Synthesis, Structure, and Reactivity of (Dihydrogen)(hydrido)iron(II) Complexes Bearing Chiral Diphosphanes
2015
The heterolytic cleavage of molecular hydrogen by [Fe(H2O)6][BF4]2 and the chiral phosphane (+)-1,2-bis[(2R,5R)-2,5-dimethylphospholano]benzene [(R,R)-Me-DuPhos] or its enantiomer [(S,S)-Me-DuPhos] yields the (dihydrogen)(hydrido)iron complexes [FeH(2-H2){(R,R)-Me-DuPhos}2]BF4 ([R,R-1]BF4) and [FeH(2-H2){(S,S)-Me-DuPhos}2]BF4 ([S,S-1]BF4), respectively. These complexes are fluxional in solution at room temperature, and the trans isomers are observed at 200 K. The ()-cis-[R,R-1]BF4 complex was identified crystallographically as the only stereoisomer at room temperature. The energetic and structural differences between the cis ( and ) and trans isomers were analyzed from a computational (DFT)…
Intramolecular Communication in Anionic Oxidized Phosphanes through a Chelated Proton
2015
Oxidation of the 1,2-(PR2 )2 -1,2-closo-C2 B10 H10 (R=Ph, iPr) platform with hydrogen peroxide in acetone is a two-step procedure in which partial deboronation of the closo cluster and oxidation of the phosphorus atoms occur. Based on NMR spectroscopic and kinetic data, we demonstrate that the phosphorus atoms are oxidized in the first step, followed by cluster deboronation. DFT calculations and natural-bond orbital (NBO) analysis were used to obtain insight into the electronic structures of diphosphane ortho-carborane derivatives.
Rhema ghennàion. Responsabilità ‘genetica’ del poeta tragico nelle Rane di Aristofane
2017
Questo contributo si propone di indagare il rapporto tra cultura e politica nelle Rane di Aristofane attraverso una delineazione delle nozioni di responsabilità e merito nella figura del poeta tragico au-spicata da Aristofane. Dall’appartenenza del poeta alle Muse, che si configura nella sua partecipa-zione ai loro Misteri, discende una sua responsabilità ‘genetica’: il poeta utile alla polis è infatti fer-tile (γόνιμος), ovvero, è in grado di fecondare il teatro, e quindi la città, di valori che, ispirandosi agli insegnamenti del passato, educhino i cittadini. Intorno al concetto di ‘nobiltà’ (γενναιότης), unito a quello di fecondità (sulla base della radice *γεν-), si sviluppa l’idea di u…