Extended tetrathiafulvalenes

Extended tetrathiafulvalenes with acetylenic cores are interesting compounds because of their redox and chromophoric properties. Such molecules are both interesting from materials and supramolecular chemistry perspectives. A tetraethynylethene-extended tetrathiafulvalene, for instance, was prepared using a microwave-promoted Sonogashira reaction [72]. Coup-... 

The most common linker molecules are pyrene derivatives, which have been used, for example, to link Au [64,65] and Pd [66] NPs, as well as QDs [67] to CNTs. Martin et al. chemically attached a n-extended tetrathiafulvalene (exTFF) group to pyrene prior to n-n hybridization on SWCNTs in order to investigate donor-acceptor interactions between the SWCNT and electron rich exTFF [68], More recently, the same group has synthesized a complex molecule consisting of two exTFF anchors connected via a flexible linkage that also consists of a second generation carboxylic terminated den-dron [69]. Here, n interactions between the exTFF anchors and the SWCNTs lead to hybridization while the carboxylic acid groups of the dendron (when de-protonated) lead to increased solubility in aqueous solutions [69]. 

Katsukis, G. Romero-Nieto, C. Malig, J. Ehli, C. Guldi, D.M., Interfacing Nanocarbons with Organic and Inorganic Semiconductors From Nanocrystals/Quantum Dots to Extended Tetrathiafulvalenes. Langmuir 2012,28 11662-11675. 

Photoinduced intramolecular electron transfer in the donor-acceptor complex 87 (R = H) generates transient charge-separated open-shell species with the remarkably long lifetime of about 75 ps [89]. Dyads that contain Tt-extended tetrathiafulvalene units also form stable cationic species upon oxidation [90]. The dumbbell shaped triad 91 [91-93] (Scheme 4.13) was obtained by carrying out the reaction with the in situ generated bis-diene at room temperature, in the dark and in o-dichlorobenzene as a solvent in 50% yield. The product is thermally unstable and easily undergoes a retro-Diels-Alder reaction [91]. 

In the course of exploring new synthetic routes to extended tetrathiafulvalene (TTF) derivatives, lithiation of S,S-acetals, followed by reaction with CS2 and PhCOCl, gave a-dithiomethylenes, which are possible versatile intermediates to extended TTFs. 1,2,3,5,6-Pentathiepanes 86 (Figure 25) were prepared from these intermediates <1995MI1>. 

Fig. 6-1 Examples of soluble and fully conjugated oPPV molecular wires covalently connected to a C60 electron acceptor and an extended tetrathiafulvalene derivative (exTTF) electron donor (C/sn-oWV-exTTF). These triads exhibit wire-like behavior and electron transfer over distances of 40 A and beyond...

The group of Professor Nazario Martin developed the synthesis of several donor-acceptor arrays containing -conjugated oPPEs of different length linking -extended tetrathiafulvalene (exTTF) as electron donor and C o as electron acceptor. Thereby, they systematically increased the length of the molecular wire from the monomer to the trimer. A detailed description of the corresponding synthesis is described elsewhere [8]. 

This chapter deals with the synthesis, reactivity, and characterization of five-membered heterocycles containing two ring sulfur atoms (1,3-dithiole derivatives) and is a review of the literature in the period 1995-2006. Previous reviews covered the literature till 1982 (CHEC(1984)) <1984CHEC(6)813> and 1995 (CHEC-II(1996)) <1996CHEC-11(3)607>. Among 1,3-dithiole compounds, 1,3-dithiolylium ions 1, mesoionic l,3-dithiol-4-ones 2, mesoionic 1,3-dithiole-4-thiones 3, 1,3-dithioles 4, 1,3-dithiolanes 5, and the tetrathiafulv alene (TTF) system 6 as a special class of compounds are discussed. 7l-Extended tetrathiafulvalenes (7t-exTTFs) containing more than one conjugated multiple bond between two 1,3-dithiole moieties are also discussed, in conjunction with 6. 

Relationships between molecular structure, electrochemical properties, and solid-state organization of salts of extended tetrathiafulvalene analogs 05CSR69. 

P. Leriche, J. M. Raimnndo, M. Turbiez, V. Monroche, M. Allain, F. X. Sauvage, J. Roncali, P. Frere and P. J. Skabara, Linearly extended tetrathiafulvalene analogues with fused thiophene units as pi-conjugated spacers, J. Mater. Chem., 13, 1324-1332 (2003). 

Kodis, G. et al. Photoinduced electron transfer in Jt-extended tetrathiafulvalene-porphyrin-fuUerene triad molecules. J. Mater. Chem. 12, 2100-2108, 2002. 

Acetylene-Extended Tetrathiafulvalenes in Cross-Conjugated Systems... 

Figure 9.11 Longest-wavelength absorption maxima of extended tetrathiafulvalenes/ dendralenes.

Moreover, supra-molecular systems involving crown ethers, fullerene and k-extended systems have been achieved that can mimic the photosynthetic process [9-14]. The fullerene Qo has been used successfully as an electron acceptor in the construction of model photosynthetic systems [9], the r-extended systems, such as porphyrins [12], phthalocyanines [13], r-extended tetrathiafulvalene (w -exTTF) derivatives [9,10], which are utilized as electron donors, while the crown ethers act as a bridge between the electron donor and acceptor. In the absorption spectrum of the complexes, the absorption maxima are associated experimentally and theoretically with the formation of charge-transfer states [14-16]. Consequently, these supramolecular systems have potential for applications in photonic, photocatalytic, and molecular optoelectronic gates and devices [9-14]. As a result, the study of the conformations and the complexation behavior of crown ethers and their derivatives are motivated both by scientific curiosity regarding the specificity of their binding and by potential technological applications. 

The complexes of dibenzo-18-crown-6 ether and of dibenzo-18-crown-6 ether of fulleroN-methylpyrrolidine with the diphenylammonium cation, PhaNHj, and its derivative with r-extended tetrathiafulvalene, r-exTTF, were investigated by employing density functional theory. We calculated geometries, complexation energies and some absorption spectra of the lowest energetic minima of the above complexes in the gas phase as well as in CHCI3 solvent. A summary of our main results follows ... 

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