Av 360

Reagent 1 was prepared according to a known procedure.^{34 (link), 35} Photographs to illustrate the change in color during the assays were acquired using a Nikon digital camera (D40, D3100). Proton nuclear magnetic resonance (¹H-NMR) spectra and carbon nuclear magnetic resonance spectra (¹³C-NMR) were recorded using a Bruker DRX-400 (400 MHz), Bruker CDPX-300 (300 MHz), Bruker DPX-300 (300 MHz) or AV-360 (360 MHz) at 25 °C. Proton chemical shifts are expressed in parts per million (ppm, δ scale) and are referenced to chloroform (CDCl₃, 7.26 ppm), or deuterated water (D₂O, 4.27 ppm). UV/vis spectroscopic data was obtained using a Beckman Coulter DU 800 spectrometer.

The structures of OFP and X-OFP were confirmed by ¹H and ³¹P NMR spectroscopy using a Bruker AV-360 instrument operated at 360 and 145 MHz, respectively. ³¹P NMR spectra were proton decoupled. ¹ H shifts are reported in ppm relative to tetramethylsilane at 0 ppm, and ³¹P shifts are reported in ppm relative to 85% H₃PO₄ at 0 ppm. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra were measured with a FTIR Bruker V70 spectrometer using polymer films directly. Molecular weights were obtained by gel permeation chromatography using a Hewlett-Packard 1047A refractive index detector and two Phenomenex Phenogel linear 10 columns, eluted at a rate of 1.0 mL/min using a 10 mM solution of tetra-n-butylammonium nitrate in THF. The elution times were calibrated with polystyrene standards. Glass transition temperatures (T_g) were measured using a TA Instruments Q10 DSC unit operated at a ramping rate of 10 °C/min from −100 °C to 100 °C and a samples size of ~10 mg, with analysis performed on a TA Instruments Universal Analysis 2000 software.