Calculation and interpretation of the vibrational spectrum of 2,2,6,6-tetramethyl-1-oxylpiperidine

The vibrational group frequency of the N–O stretching band of nitroxide stable free radicals

“…In those instances, spectral comparisons with 15 N or 18 O analogues were required for confirmation. Thus, the positions of ν(N-O • ) of the 6-membered rings, TEMPONE and TEMPOL, were determined to be 1380 and 1371 cm -1 , respectively, by 15 N substitution [13], and 1339 cm -1 in the case of TEMPO by 18 O substitution [14], to give a range of 1380 -1339 cm -1 for 6-membered cyclic nitroxides. Finally, many years after it was first proposed, 15 N measurements were undertaken to confirm 1337 cm -1 for ν(N-O • ) of the acyclic DTBN [15].…”

“…In the Grigor'ev paper a 15 was a function of ring size analogous to the C=O stretch of cyclic ketones. The findings that the peak positions of 5-membered cyclic nitroxides were up to 60 cm -1 higher than the known nitroxide range were at odds with the reports cited in the reviews [4,5] …”

Monitoring SEIRAS on a Graphitic Electrode for Surface-Sensitive Electrochemistry: Real-Time Electrografting

“…Interpretation of ATR data is based on previously reported IR assignments for graphene, graphene oxide, and 4-amino-TEMPO (Table S1). ,,− Figure a shows the time-resolved spectra acquired while maintaining a 1.1 V potential for 10 min in a 1 mM 4-amino-TEMPO PBS solution. The main IR bands during the graft are positive 1574 cm –1 and negative 1592 cm –1 attributed to the aromatic CC bonds of the graphene .…”

“…The graphene-gold was validated by successfully monitoring the electrografting of 4-amino-2,2,6,6-tetramethyl-1-piperidine N -oxyl (4-amino-TEMPO) and 4-nitrobenzene diazonium (4-NBD) onto a graphene interface. 4-Amino-TEMPO is a stable aminoxyl radical-containing species (N–Ȯ) that exhibits a reversible electrochemical response and has been previously studied using infrared spectroscopy. , The electrooxidation of 4-amino-TEMPO allows the grafting of the molecule onto electrodes via amine bridging. − 4-NBD has been previously used as a probe to understand electrografting processes due to its clear spectral signal stemming from the nitro (NO 2 ) stretches and its redox behavior . The electroreduction of diazonium-containing species, such as 4-NBD, is a well-known process for functionalizing carbon electrodes and has been extensively studied both electrochemically ,− and spectroscopically. − …”