Impact of Chlorine Substitution on Electron Spin Relaxation of a Trityl Radical.

A perchlorotriarylmethyl tricarboxylic acid radical 99% enriched in C at the central carbon (C-PTMTC) was characterized in phosphate buffered saline solution (pH = 7.2) (PBS) at ambient temperature. Samples immobilized in 1:1 PBS:glycerol or in 9:1 trehalose:sucrose were studied as a function of temperature.

Perchlorinated Triarylmethyl Radical 99% Enriched C at the Central Carbon as EPR Spin Probe Highly Sensitive to Molecular Tumbling.

Soluble stable radicals are used as spin probes and spin labels for in vitro and in vivo electron paramagnetic resonance (EPR) spectroscopy and imaging applications. We report the synthesis and characterization of a perchlorinated triarylmethyl radical enriched 99% at the central carbon, . The anisotropy of the hyperfine splitting with the C ( = 26, = 25, = 199.

Synthesis of hydroxyethyl tetrathiatriarylmethyl radicals OX063 and OX071.

We report the synthesis of hydroxyethyl tetrathiatriarylmethyl radical and its deuterated analogue for biomedical EPR applications.