Spin dynamics of C[sub 60] triplets

Journal Article · Thu Aug 04 04:00:00 EDT 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100082a013· OSTI ID:6970679

Steren, C A; Willigen, H van ^[1]; Dinse, K P ^[2]

---

1. Univ. of Massachusetts, Boston, MA (United States)
2. Technical Univ. Darmstadt (Germany)

A study of the photoexcited triplet state of C[sub 60] ([sup 3]C[sub 60]) in liquid solution (toluene, methylcyclohexane) was made using pulsed-EPR techniques. The spin-lattice relaxation time (T[sub 1]), phase-memory time (T[sub m]), and line width ([Delta][nu][sub 1/2]) were measured as function of temperature (170-360 K). The results were used to analyze some aspects of the spin dynamics of [sup 3]C[sub 60]. The data confirm earlier findings that the relaxation toward Boltzmann equilibrium is responsible for the initial growth of the signal amplitude when FT-EPR spectra are measured as a function of delay time between laser excitation and [pi]/2 microwave pulse. Also, it is found that [Delta][nu][sub 1/2] = 1/[pi]T[sub m] in both solvents over the whole temperature range. This establishes that there is a negligible contribution to the line width from unresolved [sup 13]C hyperfine structure. The contribution of the electron spin-spin interaction modulated by rotational motion to the relaxation rates is analyzed. The analysis shows that the value of the zero-field splitting parameter D, which determines the magnitude of this contribution, is about an order of magnitude less than that found in rigid matrices at low temperature. 26 refs., 9 figs., 1 tab.

• DOE Contract Number: FG02-84ER13242
• OSTI ID: 6970679
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:31; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ALKANES
ALKYLATED AROMATICS
AROMATICS
CARBON
CYCLOALKANES
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FULLERENES
HYDROCARBONS
LASERS
LINE WIDTHS
MAGNETIC RESONANCE
MATHEMATICAL MODELS
MICROWAVE RADIATION
MIXTURES
MULTIPLETS
NONMETALS
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
RADIATIONS
RELAXATION
RESONANCE
SOLUTIONS
SPIN-LATTICE RELAXATION
TOLUENE
TRIPLETS