> You have an unassailable right to deposit your peer-reviewed, accepted
> final drafts (postprints) of your ACS articles in your Institutional
> Repositories.

Well, let's clarify this just a bit.  You certainly have an
"unassailable right" to write an article and to place it in an
institutional repository.  Alternatively, you also have an "unassailable
right" to submit your article for formal publication in a journal.
However, if your article is accepted by the journal, publication may be
contingent upon your agreement not to also distribute that article
freely through some other venue (such as a publicly-available IR).
Based on a quick perusal of ACS's various copyright-assignment
documents, this seems generally to be the case with their journals.

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Rick Anderson
Dir. of Resource Acquisition
University of Nevada, Reno Libraries
(775) 682-5664
rickand@unr.edu