Abstract
Electron spin resonance measurements of Heisenberg spin-exchange rates have been used to determine the formation constants (K/sub a/) and thermodynamic parameters for the complexation reactions involving di-tert-butyl nitroxide (DTBN), 3-carbamoylproxyl (CAPRO), 3-(aminomethyl)proxyl (AMPRO), and the complexing agent ..cap alpha..-cyclodextrin (proxyl = 2,2,5,5-tetramethyl-pyrrolidinyl-1-oxy). At 298 K the K/sub a/ values for DTBN, CAPRO, and AMPRO are 6.0 +/- 1, 3.3 +/- 1, and 4.9 +/- 1. The ..delta..H and ..delta..S values determined from the formation constants are as follows: -33 +/- 6 kJ, -94 +/- 18 J K/sup -1/ (DTBN); -22 +/- 7 kJ, -64 +lt. slash- 20 J K/sup -1/ (CAPRO); -33 +/- 8 kJ, -97 +/- 25 J K/sup -1/ (AMPRO). Rate constants for exchange reactions involving radical-radical collisions, radical-complex collisions, and complex-complex collisions are reported. Possible structures for the complexes are discussed in terms of the measured equilibrium and rate constants.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
