SYNOPSISPolystyrenes, polyacrylates, and poly ( 3,4-isoprenes) incorporating the hexafluorodimethylcarbinol functionality have been synthesized, characterized, and tested as microsensor coatings on a surface acoustic wave (SAW) device for dimethyl methylphosphonate ( DMMP ) vapor absorption sensitivity. The syntheses involved monomer functionalization and polymerization or hexafluoroacetone reaction with preformed polymer. All fluoroalcohol functionalized polymer coatings displayed sub parts per million level sensitivity with the slope of the absorption isotherm steepest a t low DMMP concentrations. The order of sensitivity for the isomeric polystyrene fluoroalcohols (meta > para %-ortho) paralleled that of the relative free hydroxyl to hydrogen-bonded hydroxyl content. Strong hydrogen bonding between the fluoroalcohol polymers and DMMP vapor was observed by IR spectroscopy. Acylation of the fluoroalcohol group markedly reduced the DMMP sensitivity.

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The electrochemistry of perfluorotetracyclobuta-l,3,5,7-cyclooctatetraene (1) (a flat cyclooctatetraene) shows two reversible one-electron reductions at 0.79 and 0.14 V vs. SCE. The apparent electron-transfer rate constant for the first reduction is 0.07 ± 0.02 cm/s. The first reduction potential of 1 is more than 2.3 V positive of cyclooctatetraene (COT), and the apparent rate constant is more than an order of magnitude higher. It is suggested that the larger electron transfer rate constant for 1 compared with COT is due to the lower molecular reorganization energy required to reach the transition state for electron transfer. The unusually positive reduction potential of 1 is probably due at least in part to the 16 fluorine atoms.We report our findings on the electrochemistry of perfluorotetracyclobuta-1,3,5,7-cyclooctatetraene,1 1, which is one of the most powerful neutral organic oxidants known, reducing at positive 0.79 V vs. SCE.

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