Reorganization energies of ferrocene-peptide monolayers.
To deepen understanding of the electron transfer through a peptide backbone, we have investigated a series of noncyclic and cyclic ferrocene-peptide (Fc-peptide) cystamine conjugates immobilized on the gold microelectrode. Interaction of the ferrocenium group with BF4-, ClO4-, and PF6- as counterions was explored and the electron-transfer rates and reorganization energies were determined by variable temperature cyclic voltammetry. The highest reorganization energy was observed for the BF4- counterion, which has the weakest ability to associate with the ferrocenium cation. In addition, the more rigid cyclic Fc-peptide conjugates have a smaller reorganization energy ranging from 0.3 to 0.5 eV compared to less rigid noncyclic Fc-peptide cystamine conjugates which have higher reorganization energies in the range of 0.5-1.0 eV, which suggests that the dynamic properties of the conjugate play a role in mediating electron transfer in these systems.
Orlowski
Grzegorz A
GA
Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Chowdhury
Somenath
S
Kraatz
Heinz-Bernhard
HB
D004583:Electrons; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D008567:Membranes, Artificial; D000075163:Metallocenes; D008958:Models, Molecular; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry*; D013237:Stereoisomerism; D013499:Surface Properties; D013816:Thermodynamics
D005296:Ferrous Compounds; D008567:Membranes, Artificial; D000075163:Metallocenes; D010455:Peptides; D006046:Gold; C004998:ferrocene