Inhibition of cluster phenomena in truly water soluble fullerene derivatives: Bimolecular electron and energy transfer processes

Journal Article · Thu Mar 04 04:00:00 EST 1999 · Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical

DOI:https://doi.org/10.1021/jp983849z· OSTI ID:347559

Guldi, D M; Hungerbuehler, H; Asmus, K D ^[1]

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1. Univ. of Notre Dame, IN (United States). Radiation Lab.

A series of water-soluble fullerene derivatives, namely, e-C{sub 60}[C(COO{sup {minus}}){sub 2}]{sub 2} (2), trans-3-C{sub 60}[C(COO{sup {minus}}){sub 2}]{sub 2} (3), trans-2-C{sub 60}[C(COO{sup {minus}}){sub 2}]{sub 2} (4), and e,e,e-C{sub 60}[C(COO{sup {minus}}){sub 2}]{sub 3} (5) were probed in light- and radical-induced studies and compared to {l_brace}({sup 3}C{sub 60})C(COO{sup {minus}}){sub 2}{r_brace}{sub n} clusters (1). Ground-state absorption spectra of 2--5, recorded in a concentration range between 1.0 {times} 10{sup {minus}4} M and 5 {times} 10{sup {minus}6} M, clearly speak against any appreciable deviation from the Lambert-Beer law. Picosecond-resolved photolysis gives rise to singlet excited state absorptions that closely resemble earlier observations for e-C{sub 60}[C(COOEt){sub 2}]{sub 2}, trans-3-C{sub 60}[C(COOEt){sub 2}]{sub 2}, trans-2-C{sub 60}-[C(COOEt){sub 2}]{sub 2}, and e,e,e-C{sub 60}[C(COOEt){sub 2}]{sub 3} in deoxygenated toluene solutions. The triplet lifetimes of 2--5, as measured by nanosecond-resolved photolysis, are typically around 40 {micro}s, similar to the triplet lifetimes of truly monomeric fullerene solutions. A strongly enhanced lifetime (by nearly 3 orders of magnitude) relative to {l_brace}({sup 3}C{sub 60})C(COO{sup {minus}}){sub 2}{r_brace}{sub n} clusters (1) ({tau} = 0.4 {micro}s) indicates a truly monomeric appearance of these bis- and tris-functionalized fullerenes in aqueous solutions and confirms that micellar aggregation does, indeed, play only a minor role regarding the reactivity of these derivatives. As a consequence of reductive quenching, the spectral region between 900 and 1,100 nm shows the time-resolved growths of the {pi}-radical anions absorptions with maxima at 1,040, 995, and 880, and 1,020 nm, for 2, 3, 4, and 5, respectively. They match the spectra generated by means of hydrated electrons (k = (0.75--3.4) {times} 10{sup 9} M{sup {minus}1} s{sup {minus}1}) and (CH{sub 3}){sub 2}{sup {sm_bullet}}COH radicals (k = (0.9--2.2) {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}) in pulse radiolysis experiments.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• OSTI ID: 347559
• Journal Information: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Journal Name: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical Journal Issue: 9 Vol. 103; ISSN 1089-5647; ISSN JPCBFK
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTRA
AQUEOUS SOLUTIONS
CARBOXYLIC ACIDS
CHEMICAL PROPERTIES
ELECTRON TRANSFER
ENERGY TRANSFER
EXCITED STATES
EXPERIMENTAL DATA
FULLERENES