title: Ring-strain effects on the oxidation potential of enediynes and enediyne complexes.
abstract: The metal-enediyne complexes [(eta 5-C5H5)Fe[eta 5-1,2-C5H3C identical to C(CH2)nC identical to]] (4, n = 4; 5, n = 5) and [(eta 5-C5H5)-Fe[eta 5-1,2-C5H3(C identical to C Me)2]] (6) were prepared from 1,2-diethynylferrocene (3). Complexes 4 and 5 were characterized in the solid state by X-ray crystallographic analysis. The structures of 4 and 6 were determined by computation using ab initio methods. A correlation was observed between ring-strain and increased ease of electrochemical oxidation along the series 6 (+0.164 V) to 5(+0.152 V) to 4 (+0.123 V). A similar trend in ionization potentials was identified in both the gas phase and in solution by computational methods.
authors.affiliation: Department of Chemistry and Biochemistry, University of California at San Diego, San Diego Supercomputer Center, La Jolla, California, USA.
authors.forename: Kim K
authors.initials: KK
authors.lastname: Baldridge
authors.forename: Bernadette T
authors.initials: BT
authors.lastname: Donovan-Merkert
authors.forename: Joseph M
authors.initials: JM
authors.lastname: O'Connor
authors.forename: Linda I
authors.initials: LI
authors.lastname: Lee
authors.forename: Adam
authors.initials: A
authors.lastname: Closson
authors.forename: Daniel
authors.initials: D
authors.lastname: Fandrick
authors.forename: Tuan
authors.initials: T
authors.lastname: Tran
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Bunker
authors.forename: Mouffouk
authors.initials: M
authors.lastname: Fouzi
authors.forename: Peter
authors.initials: P
authors.lastname: Gantzel
mesh_terms: D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011743:Pyrimidines / Q000737:chemistry*
chemical_list: D008670:Metals; D011743:Pyrimidines