Surface reactivity studies of bimetallic complexes, (eta(5)-C5Me5)Re(NO)(PPh3)(C equivalent to C)(n)(Ph3P)(ON)Re(eta(5)-C5Me5) (n=2,4,6): candidates for molecular wires

Conjugated polyalkynyl carbon chains, candidates for molecular wires, (eta( 5)-C5Me5)Re(NO)(PPh3)(C drop C)(n)(Ph3P)(ON)Re(eta(5)-C5Me5) (n=2 (Re*C4Re* ), 4(Re*C8Re*), 6(Re*C12Re*)), have been deposited as thin films on air pas sivated copper surfaces and examined by X-ray photoelectron spectroscopy be fore and after exposure to air for various periods of time. The reactivity patterns of these thin films have been determined by examination of the oxi dation state of Re and the chemical states of carbon, oxygen and phosphorus . Rhenium, which is zero valent in the starting compounds (Re*C4Re*), (Re*C 8Re*) and (Re*C12Re*) reacts to form Re3+, Re4+ and Re5+. Their thin film r eactivities will be discussed and compared to their solution electrochemist ry. We have found Re*C4Re* and Re*C8Re* to be more reactive than Re*C12Re* in agreement with the cyclic voltammetry results. (C) 2000 Elsevier Science Ltd. All rights reserved.