SELF-ASSEMBLED MONOLAYERS WITH CHARGE-TRANSFER GROUPS - N-MERCAPTOALKYL-TETRATHIAFULVALENECARBOXYLATE ON GOLD

The syntheses of n-mercaptoalkyl tetrathiafulvalenecarboxylates (n = 1 6,12,11,8) and the electrochemical and structural properties of self-a ssembled monolayers derived from these compounds are described. Self-a ssembled monolayers of the title compound on gold electrodes displayed voltammetric responses characteristic of the TTF subunit. Infrared re flectance absorbance spectroscopy suggests that the monolayer consists of liquid-like alkyl chains. Exposure of a monolayer of 1 (n = 16) to tetracyanoquinodimethane (TCNQ) results in formation of a monolayer c ontaining a novel charge-transfer unit nominally described as Au-S-(CH 2)16-OC(=O)-TTF+TCNQ-. Spectroscopic data suggest that the TCNQ- anion adopts an orientation parallel to the gold substrate.