Stability of water-stable C60 clusters to OH radical oxidation and hydrated electron reduction.
Reactions of water-stable C(60) clusters (nC(60)) in water with OH radicals (*OH) and hydrated electrons (e(aq)(-)), generated by steady-state gamma-radiation, were observed and characterized. Ordered C(60) clusters were relatively recalcitrant to highly reactive *OH and e(aq)(-) species, with only a fraction of carbons oxidized and reduced, respectively. Pulse radiolysis suggested that the reactions of nC(60) with OH* and e(aq)(-) were diffusion limited, with rate constants of (7.34 +/- 0.31) x 10(9) M(-1) s(-1) and (2.34 +/- 0.02) x 10(10) M(-1) s(-1), respectively. Quantum mechanical calculations of binding energy of the C(60)-OH adduct as a function of C(60) clustering degree indicate, despite an initial fast reaction, a slower overall conversion due to thermodynamic instability of C(60)-OH intermediates. The results imply that ordered clustering of C(60) in the aqueous phase significantly hinders C(60)'s fundamental reactivity with radical species.
Lee
Jaesang
J
School of Civil and Environmental Engineering, and Department of Chemistry, Rice University, Houston, Texas 77005, USA.
Song
Weihua
W
Jang
Seung S
SS
Fortner
John D
JD
Alvarez
Pedro J J
PJ
Cooper
William J
WJ
Kim
Jae-Hong
JH
D004583:Electrons; D037741:Fullerenes / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D011789:Quantum Theory; D013816:Thermodynamics; D014867:Water
D037741:Fullerenes; D014867:Water; D017665:Hydroxyl Radical; C069837:fullerene C60