Tga 550

(Nitronyl nitroxide-2-ido)(triphenylphosphine) gold(I) 4 is synthesized by the reaction of nitronyl nitroxide 7 and Au^I(PPh₃)Cl with NaOH in methanol/dichloromethane.^{41 ,83 ,84 (link)} After purification by chromatography (deactivated Al₂O₃), the spin concentration of 4 is up to 99%. Di-iodo-Blatter radical 5 and its mono-iodo analogue 6 are prepared according to previous literature.^{45 (link),46} Frozen and liquid solution EPR spectra were obtained using a Bruker EMX-plus X-band spectrometer and simulated with the EasySpin software.^{56 (link)} The TGA instrument (TA Instruments TGA 550) was run either without or with IR attachment (Thermo NICOLET Is50 NIR). Variable temperature (from 1.8 K to up to 370 K) magnetic susceptibility measurements of 3 were performed using a Quantum Design SQUID magnetometer with applied magnetic fields of 30 000 and 5000 Oe. Variable field (0 – 50,000 Oe) magnetization studies were carried out at temperatures of 1.8 – 5 K. Sample tubes for SQUID studies in dilute matrices^{85 (link)} are described in the SI.

Frozen solution EPR spectra were obtained using a Bruker EMX or EMX-plus X-band spectrometer and simulated with the EasySpin software.^{28 (link)} The TGA/DSC or TGA instrument (TA Instruments TGA 550) was run either without or with IR attachment (Thermo NICOLET Is50 NIR). Variable temperature (from 1.8 K to up to 370 K) magnetic susceptibility measurements of 1 and 2 were performed using a Quantum Design SQUID magnetometer with applied magnetic fields of 30 000, 5000, and 500 Oe. Variable field (0 – 50,000 Oe) magnetization studies were carried out at temperatures of 1.8 – 5 K. Sample tubes for SQUID studies in dilute matrices are described in the SI.^{61 (link)}