Nitroxide-labeled ruthenium(II)-polypyridyl complexes as EPR probes to study organized systems. 1. Micellar solutions and micellization of sodium alkyl sulfates

Journal Article · Thu Jul 09 04:00:00 EDT 1992 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100193a078· OSTI ID:273616

Ottaviani, M F ^[1]; Ghatlia, N D; Turro, N J ^[2]

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1. Columbia Univ., New York, NY (United States)
2. Univ. of Florence, Firenze (Italy)

EPR probes that structurally resemble ruthenium(II) trisphenanthroline complexes have been utilized to monitor the binding and dynamics of these complexes with different anionic detergents in aqueous solutions. The results and interpretation of these EPR experiments are compared with the results and interpretations of photophysical studies involving interactions of ruthenium(II)-trisphenanthroline complexes and micelles. The EPR spectra have been evaluated in terms of both the hyperfine splitting (a polarity-sensitive parameter) and the rotational correlation time (a dynamics parameter). All experimentally recorded spectra could be successfully simulated as a single component or as the superposition of two components. Stronger binding of these probes is observed as the chain length of the detergent increases. For the same chain length, stronger interactions are observed for micelles containing a sulfate head group compared to a carboxylate group. The rotational diffusional coefficients obtained are found to correlate extremely well with the translational diffusion coefficients obtained in photophysical studies. Previously reported observations of the formation of premicellar aggregates at concentrations below the critical micelle concentration (CMC) have also been corroborated in this study. 16 refs., 11 figs.

• Sponsoring Organization: USDOE
• OSTI ID: 273616
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 14 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
DETERGENTS
ELECTRON SPIN RESONANCE
HYPERFINE STRUCTURE
MICELLAR SYSTEMS
RUTHENIUM COMPLEXES
STRUCTURAL CHEMICAL ANALYSIS