Ring-strain effects on the oxidation potential of enediynes and enediyne complexes.
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.
Baldridge
Kim K
KK
Department of Chemistry and Biochemistry, University of California at San Diego, San Diego Supercomputer Center, La Jolla, California, USA.
Donovan-Merkert
Bernadette T
BT
O'Connor
Joseph M
JM
Lee
Linda I
LI
Closson
Adam
A
Fandrick
Daniel
D
Tran
Tuan
T
Bunker
Kevin D
KD
Fouzi
Mouffouk
M
Gantzel
Peter
P
D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011743:Pyrimidines / Q000737:chemistry*
D008670:Metals; D011743:Pyrimidines