Thermodynamically stable [4 + 2] cycloadducts of lanthanum-encapsulated endohedral metallofullerenes

• Yuta Takano,
• Yuki Nagashima,
• M. Ángeles Herranz,
• Nazario Martín and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2014, 10, 714–721, doi:10.3762/bjoc.10.65

• in situ from the sultine 4,5-benzo-3,6-dihydro-1,2-oxathiin 2-oxide and its derivative, to La metal-encapsulated fullerenes, La2@C80 or La@C82, afforded the novel derivatives of endohedral metallofullerenes (3a,b, 4a,b and 5b). Molecular structures of the resulting compounds were elucidated using

• ]. The encapsulation results in the electron transfer from metal atoms to the fullerene cage, which leads to unique electronic, magnetic, and chemical properties for EMFs that cannot be expected for empty fullerenes. Due to the numerous electronic properties EMFs are anticipated as promising materials in

• fullerenes simultaneously possess a low ionizing potential and a high electron affinity [1][2]. For mono-La endohedral fullerenes such as La@C82, the electron transfer results in paramagnetism of the fullerene cage [5]. The di-La endohedral fullerenes such as La2@C80 show diamagnetism [6]. This feature leads

Tuning the interactions between electron spins in fullerene-based triad systems

• Maria A. Lebedeva,
• Thomas W. Chamberlain,
• E. Stephen Davies,
• Bradley E. Thomas,
• Martin Schröder and
• Andrei N. Khlobystov

Beilstein J. Org. Chem. 2014, 10, 332–343, doi:10.3762/bjoc.10.31

• ; fullerene triads; spin–spin interactions; Introduction Fabricating molecular systems that are capable of storing one or more unpaired electrons is essential for the development of molecular spintronics and electron-spin-based quantum computing. Endohedral fullerenes are compounds that contain a heteroatom

• of N@C60–N@C60 molecules [5][6][7]. However the application of these systems is limited due to a number of synthetic challenges associated with the preparation and purification of endohedral fullerenes [8]. This notwithstanding, fullerene cages are excellent electron acceptors and can support up to

• the nature of the fullerene cages resulting in the preparation of six fullerene–linker–fullerene (triad) compounds (Figure 1). The fullerenes were functionalised via Prato reaction chemistry forming a pyrrolidine ring across the [6.6] bond of the cage [21]. The resulting pyrrolidine functionalised

A study on electrospray mass spectrometry of fullerenol C₆₀(OH)₂₄

• Mihaela Silion,
• Andrei Dascalu,
• Mariana Pinteala,
• Bogdan C. Simionescu and
• Cezar Ungurenasu

Beilstein J. Org. Chem. 2013, 9, 1285–1295, doi:10.3762/bjoc.9.145

• ], neuroprotective [4][5][6][7], and anticancer agents [8][9][10][11][12][13], polyhydroxylated [C60]fullerenes, C60(OH)x, have received much attention in recent years. However, to the best of our knowledge, except for the compositionally and structurally well characterized C60(OH)24, prepared by alkaline hydrolysis

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• donor materials in blends with solution-processable fullerenes have produced the highest efficiency organic photovoltaic bulk heterojunction (BHJ) devices to date [13][14]. The critical role of supramolecular interactions together with material behaviour at interfaces has been significant in achieving

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• values are 20.5, 19.6, 21.3 and 23.1, respectively). 5 Other applications 5.1 Hosts for fullerenes One of the remarkable characteristics of calixarenes is the bowl shape of the molecule. In the case of oxacalix[3]arenes, the bowl is quite shallow, which indicates that they may be good hosts for spherical

• guests and immediately suggests binding to fullerenes. Furthermore, the macrocyclic bowl is the perfect size for C60 and has a complementary threefold-symmetry element. Based on the knowledge that p-tert-butylcalix[8]arene was able to complex C60 [72][73] Shinkai investigated the interaction of C60 with

• 3a in 1997 by UV–vis spectroscopy [74]. In a later full paper, UV–vis absorption spectra of C60 were recorded with calix[n]arenes and oxacalix[3]arenes. The interaction of fullerenes with calixarenes affected the spectra between 420 and 450 nm [75]. By using the Benesi–Hildebrand method, 3a was shown

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• ][81], push–pull amines and betaines 74–78 [82][83][84][85][86][87], alkoxy derivatives 79,80 [88], biimidazoles 81 [89][90][91][92], and triimidazoles 82 [93][94], as well as fullerenes [95] and polymers [96][97][98][99]. The chemistry of 4,5-dicyanoimidazole was reviewed in 1987 by Donald and Webster

Synthesis of fluoranthenes by hydroarylation of alkynes catalyzed by gold(I) or gallium trichloride

• Sergio Pascual,
• Christophe Bour,
• Paula de Mendoza and
• Antonio M. Echavarren

Beilstein J. Org. Chem. 2011, 7, 1520–1525, doi:10.3762/bjoc.7.178

• synthesis of large polyarenes [40][41][42][43], which are related to the fullerenes [44], we used the palladium-catalyzed arylation reaction as the main tool [45][46][47][48]. We decided to try the triple hydroarylation of substrates of type 1 to give 3,9,15-triaryldiacenaphtho[1,2-j:1',2'-l]fluoranthenes 2

Reciprocal polyhedra and the Euler relationship: cage hydrocarbons, C_nH_n and closo-boranes [B_xH_x]²⁻

• Michael J. McGlinchey and
• Henning Hopf

Beilstein J. Org. Chem. 2011, 7, 222–233, doi:10.3762/bjoc.7.30

• original concept and propose that other highly symmetrical cage hydrocarbons of the CnHn type might have closo-borane counterparts. Indeed, Lipscomb and Massa have discussed the structures of borane analogues of fullerenes [52][53] and even of nanotubes [54]. In particular, they proposed that C60 (V, E, F

• octahedral D3d geometry [59]. Interestingly, King et al. have pointed out the reciprocal polyhedral relationship between gold clusters and fullerenes [60]. As noted above, molecular analogues of several members of both sets of the complementary polyhedra exhibited by the closo-boranes and by the

Syntheses and properties of thienyl-substituted dithienophenazines

• Annemarie Meyer,
• Eva Sigmund,
• Friedhelm Luppertz,
• Gregor Schnakenburg,
• Immanuel Gadaczek,
• Thomas Bredow,
• Stefan-S. Jester and
• Sigurd Höger

Beilstein J. Org. Chem. 2010, 6, 1180–1187, doi:10.3762/bjoc.6.135

• well as cyclic and polycyclic thiophenes are valuable templates for the epitaxial coadsorption of adlayers, in particular for fullerenes and metallacycles [14][15][16][17]. Results and Discussion Here we report the syntheses of two isomeric benzodithiophenediones, their respective phenazines and their

Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines

• Adam W. Franz,
• Svetlana Stoycheva,
• Michael Himmelhaus and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2010, 6, No. 72, doi:10.3762/bjoc.6.72

• [18], porphyrin derivatives [20], phenanthrenes [22][23], fullerenes [24], and optically active naphthalenes [25] adsorbed on gold were studied in break-junction experiments and their properties on conductance, 1-bit random access memory and, especially, with regard to their ability to function as

Synthesis of thienyl analogues of PCBM and investigation of morphology of mixtures in P3HT

• Fukashi Matsumoto,
• Kazuyuki Moriwaki,
• Yuko Takao and
• Toshinobu Ohno

Beilstein J. Org. Chem. 2008, 4, No. 33, doi:10.3762/bjoc.4.33

• methanofullerenes was performed by using dichloromethane as a solvent. es-TThCBM (3d) exhibited 1.4 times greater solubility in dichloromethane than PCBM. Keywords: fullerene; morphology; organic fullerenes; PCBM; photovoltaic cell; Introduction The demand for inexpensive, renewable energy sources continues to

• . Solubility of methanofullerenes Good solubility of fullerenes is important for fabricating a photovoltaic device with good morphology [24]. In fact, PCBM is one of the most soluble fullerene derivatives and this is the main reason why it is used for the fabrication of PV cells. Chlorobenzene is normally used

• as a solvent of P3HT and fullerenes to fabricate a bulk hetero layer by spin coating; however, chlorobenzene almost completely dissolves methanofullerenes and hence cannot be used to determine and compare the solubility of different methanofullerenes at a small scale; therefore, in this study