title: Synthesis of thiol-derivatized ferrocene-porphyrins for studies of multibit information storage
abstract: One approach toward storage of multiple bits of information at the molecular level requires the construction of molecular architectures comprised of multiple redox-active units. Four new ferrocene-porphyrins have been synthesized to investigate questions concerning (1) the scope of redox-active molecules that can be employed in molecular information-storage schemes and (2) writing/reading rates as well as retention of charge in redox-active units located at different sites in a molecular architecture. Three of the ferrocene-porphyrins have linkers of different lengths between the ferrocene and porphyrin. The fourth ferrocene-porphyrin has two ferrocenes positioned at the lateral sites on the porphyrin. The latter architecture is designed to provide a shorter distance between the electroactive surface and the ferrocene while maintaining an upright orientation of the porphyrin. Each ferrocene-porphyrin affords three cationic oxidation states (ferrocene monocation, porphyrin monocation, porphyrin dication) in addition to the neutral state, thereby affording the capability of storing two bits of information. Each ferrocene-porphyrin bears an S-acetyl or S-(N-ethyl)carbamoyl-protected thiol moiety, thereby avoiding handling of free thiols. Each ferrocene-porphyrin forms a self-assembled monolayer (SAM) on gold via in situ cleavage of the thiol protecting group. The SAM of each array is electrochemically robust and exhibits three well-resolved, reversible oxidation waves.
authors.affiliation: Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, and Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
authors.initials: DT
authors.lastname: Gryko
authors.initials: F
authors.lastname: Zhao
authors.initials: AA
authors.lastname: Yasseri
authors.initials: KM
authors.lastname: Roth
authors.initials: DF
authors.lastname: Bocian
authors.initials: WG
authors.lastname: Kuhr
authors.initials: JS
authors.lastname: Lindsey