SYNTHESIS AND SURFACE-CONFINED ELECTROCHEMISTRY OF DIMETHOXYNAPHTHALENE FUSED THROUGH RIGID NORBORNYLOGOUS SPACERS TO THIOLATE, DITHIOLATE,AND DISULFIDE GROUPS

A series of compounds (1-8) has been prepared in which a 1,4-dimethoxy naphthalene (DMN) group and either two thiol groups or a disulfide moi ety are attached to the respective termini of rigid ''norbornylogous'' hydrocarbon bridges. 3, 5, 7, 9, and 13 bonds in length. Each of the the molecules forms an adsorbate monolayer when its CH2Cl2 solutions a re exposed to etched gold. Chemically reversible one-electron oxidatio n of the DMN group is observed in CH2Cl2 or CH3CN at potentials of 0.5 4-0.67 V vs ferrocene. Repeated potential cycling demonstates less mon olayer degradation (a) in CH2Cl2 compared to CH3CN and (b) at subambie nt temperatures. Fast cyclic voltammetry experiments establish that th e electron-transfer rates between the naphthalene group and the electr ode surface are very fast (> 10(8) s(-1)).