Preparation of TTF-bsed Oligomeric Donor Hosts with Flexible Structure

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Three-dimensionally assembled TTF derivatives through their molecular architecture may exhibit markedly different properties and/or functions due to their totally different shapes from the basically flat nature of monomeric TTF derivatives.. Previously we prepared TTF dimer in which two TTF moieties are held either parallel or orthogonal through four alkylenedithio chains and their electrocrystallization gave complexes of unique electronic and/or magnetic properties.In the present study, preparation of two kinds (linear and cyclic) of flexible donor hosts has been tried. They are made of three to four TTF moieties and may form supramolecular assemblies with large three-dimensional acceptors like fullerene through "induced fit".Linear types in which the central TTF moiety is connected to the two franking TTF's through two propylenedithio groups have been successfully prepared. Two protected thiol groups are' located at both of the ends and can be easily converted to various functionalities. Their properties are, however, yet to be studied.. To the contrary, the ethylenedithio homologues are difficult to prepare, mainly due to low solubilitys of intermediates.Preparation of a macrocycle composed of four TTF's whose 4-and 5-C are both connected with a respective franking TTF moiety through propylenditho group have been tried. Quadruple TTF-forming couplings of the corresponding 1,3-dithiole-2-one/thione cyclic tetramer using standard trialkyl phosphite protocols gave only insufficiently coupled products even under the presence of a large excess of the counterpart molecule. Efforts to prepare a similar cyclic trimer connected with propylenedithio or ethylenedithio group have been also unsuccessful.Presently a new route to connect preformed three TTF's has been tried. A linear TTF trimer precursor have been prepared and its ring-forming reaction have been under scrutiny..