NMR measurements were performed at 233 MHz in a 14.1 T Unity Inova NMR spectrometer over a temperature range of 173 K to 403 K. We used a 5 mm Varian broadband probe in the temperature range 213 K to 373 K, and a 10 mm probe for measurements below 213 K and above 373 K. We used a 17.1 T