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The UV-vis absorption, MCD and fluorescence spectra of phthalocyaninatosilicon (SiPc) covalently linked to one or two TEMPO radicals have been studied in comparison with those of (dihydroxy)SiPc. The electronic absorption and MCD spectra show little change on substitution of TEMPO radicals, indicating that the electronic interaction between excited singlet SiPc (¹SiPc*) and doublet TEMPO (²TEMPO) is very weak or non-existent. In contrast, fluorescence quantum yields decrease markedly with increasing number of TEMPO radicals. This result is interpreted reasonably by assuming that the decay from ¹SiPc* to excited triplet SiPc (³SiPc*) partially becomes a spin-allowed transition owing to the interaction between ³SiPc* and ²TEMPO.

The amphiphilic TEMPO molecules consist of two dissimilar parts. One part is hydrophilic (head) and the rest part is hydrophobic (tail). The derivatives of 4-alkaneamino-2, 2, 6, 6-tetramethyl-1-piperidinyloxy radical (C_n-amino-TEMPO, n = 14, 16, 18, 20, 22) was synthesized with 4-amino-TEMPO and carboxylic acid. The C_n-amino-TEMPOs equilibrated at the air/water interface form Langmuir monolayer by classical Langmuir monolayer techniques. The stable monolayers of C_14-22-amino-TEMPOs were characterized by pressure–area isotherms. The features of collapse pressure of C_14-22-amino-TEMPOs were confirmed on alkyl chain length. Limiting area points and take-off area points from surface pressure-MMA isotherms were subjected to the influence of subphase. The monolayer of C₂₂-amino-TEMPO which has longer alkyl chain was characterized by Brewster Angle Microscopy. So we can confirm phase transition by BAM images as monolayer is expanding at the room temperature.

Novel TEMPO radical grafted PANI [polymer (3)] was synthesized from 2,5-dicarboxyaniline by two-step process, and investigated with Fourier transform infrared spectroscopy, electron spin resonance spectra, thermogravimetric analysis, scanning electron microscopy, cyclic voltammograms, and galvanostatic charge–discharge techniques. The polymer (3) shows six-electron redox reaction process in the voltage ranges of 2.0–4.0 V versus Li⁺/Li. A high specific capacity of 156 mA h g⁻¹ is obtained in the experiment, close to half of the theoretical capacity of the polymer based on six-electron redox reaction (330 mA h g⁻¹. The polymer (3) also exhibits good rate capability and cycle life. The excellent electrochemical properties benefit from fast redox reaction of nitroxy radical and conductive polyaniline nanotubes structure.