TEMPO molecule

TEMPO molecule [102] Adsorbs at single dangling bonds. Used as a barrier molecule for restricting the growth of styrene chains. 

Fukuda, 1997) as follows A mixture of benzoyl peroxide (0.072 mol L ), TEMPO (0.086 mol L ), and styrene, degassed and sealed off under vacuum, was heated at 90°C for 1 h. There was no formation of polymer as shown by GPC. Then the system was heated at 125°C for 5 h to yield a polymer (recovered by precipitation in excess methanol) with M = 1700 and = 1.11. Analysis showed that this polymer (PS) had a TEMPO molecule... 

The active piperidinyloxy copper(II) species is produced via TEMPO-mediated oxidation of Cu Cl. Replacement by a substrate molecule, followed by coordination of a second TEMPO molecule and intramolecular (3-hydrogen... 

Fig. 6 The high-field peak region of TEMPO CW EPR spectra in methacrylic-acid containing PNIPAAM copolymer networks (left). A denotes the peak from TEMPO in hydrophilic environment, while B denotes the peak from TEMPO in the collapsed regions. The spectra were recorded in the course of 120 min and in this timeframe the B type species is only minimally reduced, while the hydrophilic A species is significantly reduced due to acid-catalyzed disproportionation of TEMPO to diamagnetic compounds. The coexistence of regions, in which this chemical reaction is facilitated ( nanoreactors ) and simultaneously of regions, in which TEMPO molecules are protected from the reaction ( nanoreactors ) is schematically depicted on the right...

The aggregation and the collapse can further be characterized by analyzing the effective hyperfine coupling constants of those TEMPO molecules in hydrophobic environments and the fraction of TEMPO in hydrophilic environments as a function of temperature. By plotting these parameters vs the reduced temperature (J — Tc)/Tc it was possible to check whether the collapse results from a well-behaved phase transition. Both parameters do not follow one straight line, expected... 

We chose this as our first case study due to the many special features of the TEMPO compound(s) and also that the studies made are thorough and exemplifies the level of accuracy that has been reached for predicting the electrochemical stability of additives. There are also a number of delicate computational issues that we do not find described elsewhere for these types of additives. The core TEMPO molecule is a stable radical, with a sterically protected nitroxide. In 2006 only BDB and TEMPO had shown the required stability to act as an overcharge protecting redox shuttle [90]. 

Figure 2.6. In-situ catalytic regeneration of the TEMPO molecule.

F. 17.4 Graphical representation of the NfO-TEMPO molecule, together with the computed [167] and experimental [168] fluorescence spectrum... 

Oxidation with NaClO catalyzed by the 2,2,6,6-tetramethyl-l-piperinidyloxy (TEM PO) radical has proven to be a highly selective, fast, and well-controlled method for carboxylation of the alcohol groups in various cellulose materials [61]. Owing to the steric structure of the TEMPO molecule, only the primary C6 hydroxyls are converted into carboxyl groups (Figure 8.10) [68-70]. 

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