ARYL ESTER DENDRIMERS INCORPORATING TETRATHIAFULVALENE UNITS - CONVERGENT SYNTHESIS, ELECTROCHEMISTRY AND CHARGE-TRANSFER PROPERTIES

The convergent synthesis of a range of aryl ester dendrimers with peri pheral tetrathiafulvalene (TTF) units is reported. 4-( Hydroxymethyl)- TTF and 4,5-(2-hydroxymethylpropane-1,3-diyldithio)-TTF have been used as the starting TTF reagents. The core reagents are benzene-1,3,5-tri carbonyl trichloride, terephthaloyl chloride, biphenyl-4-4'-dicarbonyl chloride and 4,4'-oxybis(benzenecarbonyl chloride). Dendrimers compri sing up to 12 TTF units have been characterised by elemental analysis, plasma desorption mass spectrometry, H-1 NMR spectroscopy and solutio n electrochemistry. Cyclic voltammetry (CV) and ultra microelectrode C V studies show that the TTF dendrimers display nearly ideal redox beha viour for the TTF system with no significant interaction between the T TF units. Thin layer cyclic voltammetric studies show that all the TTF units of these systems undergo two, single-electron oxidations. The d endrimers form charge-transfer complexes upon reaction with iodine in solution. Intermolecular interactions of the TTF radical cations are o bserved in the UV-VIS spectra of some of the oxidised derivatives.