REPORT DOCUMENTATION PAGEReproduction in whole or in part is permitted for any purpose of the United States Government.This document has been approved for public release and sale; its distribution is unlimited. it is not oxidized at potentials up to 1.0 V. An analogous initiator containing a ferrocenylmethylidene ligand (ib) can be synthesized by treating la with vinylferrocene. Redoxactive derivatives of norbornene, containing ferrocene (2) or phenothiazine (3) were prepared and polymerized by la or lb to give living block copolymers containing the ring-opened norbornene derivatives. The living polymer was cleaved from the metal in a Wittig-like reaction with pivaldehyde, trimethylsilylbenzaldehyde, or octamethylferrocenecarboxaldehyde. Polydispersities for the longer block copolymers containing up to -80 monomer units was found to be as low as 1.05 by GPC. In one case the polydispersity of a homopolymer made from the ferrocenecontaining monomer was determined by FD-Mass Spectroscopy to be 1.06. DSC studies suggest that microphase formation occurs in the block copolymers, even in the case of relatively low 4 molecular weight materials. Solution voltammetric studies of homo and block copolymers showed that the redox centers were electrochemically independent, and that all centers exchanged electrons with the electrode. Neutral polymers became insoluble upon oxidation to a polycation, yielding an adsorbed polymer layer on the electrode that could then be cathodically stripped. This oxidative deposition process depended on the electrolyte and the polymer molecular weight, but also could be controlled by the size of a non-electroactive block ir the block copolymers. Problems resulting from precipitation of the redox polymers could be circumvented by employing normal pulse voltammetry. Polymers containing redox-active centers in both end groups, as well as in the polymer chain itself, have been prepared and shown in electrochemical studies to undergo the expected initiation, propagation, and termination reactions.
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