Car☐yverdazyls: Water-soluble organic free radicals

Mayr, Armin J.; Eastman, Michael P.; Hartzell, Cynthia J.; Dong, Dezun; McClellan, C.

doi:10.1016/0022-2364(92)90191-9

Cited by 5 publications

(4 citation statements)

References 4 publications

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“…remain almost constant, regardless both of the permittivity and of the concentration. Although a similar tendency is observed for WS-TPV, 15 the difference in l max À1 of TPV between the dispersed state and the aggregated state is one-fourth of the corresponding difference for PyC8TOV (points A and B). This observation indicates that the slope of l max À1 vs. permittivity for WS-TPV might be much smaller than that of PyC8TOV.…”

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confidence: 67%

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Association-mediated chromism of amphiphilic triphenyl-6-oxoverdazyl

et al. 2008

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We synthesized a novel amphiphilic compound, 1,5-diphenyl-3-(4-(8-(pyridin-1-ium-1-yl)octoxy)phenyl)-6-oxoverdazyl bromide (PyC8TOV) thorough modification of 1,3,5-triphenyl-6oxoverdazyl by introducing a pyridinium head group. This amphiphilic radical dissolved in water at concentrations lower than 0.1 mM but formed aggregates at higher concentrations. Depending on its concentration in water, PyC8TOV afforded crystals, or gels. The solvent-and concentration-dependences of UV and ESR spectra of PyC8TOV are discussed in terms of the environmentally sensitive electronic structure of this amphiphilic radical. The nonlinear dependence of the relaxivity of an aqueous solution of PyC8TOV strongly suggests the formation of aggregates in concentrated solution. PyC8TOV exhibited not only solvatochromism but also association-mediated chromism.

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confidence: 67%

“…Mayr et al reported the pioneering synthesis of the water-soluble TPV (WS-TPV) radical. 15 However, the hydrophilic moiety of this radical is a carboxylic group that permits the WS-TPV to dissolve only in alkaline water (pH 4 10). Furthermore, the concentration dependence of UV and ESR spectra for WS-TPV is small.…”

Section: Introductionmentioning

confidence: 99%

Association-mediated chromism of amphiphilic triphenyl-6-oxoverdazyl

et al. 2008

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“…Carboxyphenyl and hydroxyphenyl derivatives Id – If and Ig , respectively, were deprotonated, and their solubility in aqueous basic solutions was demonstrated. More recently the formation of reactive primary bromide Ih and its reaction with pyridine to form the corresponding pyridinium salt was reported .…”

Section: Introductionmentioning

confidence: 99%

“…17 The 6-oxoverdazyl system appears to be stable also to acidic conditions; 1,3,5-triphenyl-6-oxoverdazyl was sulfonylated giving water-soluble trisulfonium acid Ic. 18 Carboxyphenyl 19 and hydroxyphenyl 20 derivatives Id−If and Ig, respectively, were deprotonated, and their solubility in aqueous basic solutions was demonstrated. More recently the formation of reactive primary bromide Ih and its reaction with pyridine to form the corresponding pyridinium salt was reported.…”

Section: ■ Introductionmentioning

confidence: 99%

Functional Group Transformations in Derivatives of 6-Oxoverdazyl

et al. 2013

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Transformations of functional groups, such as OCH2Ph, OCOPh, NO2 and I, in 1,3,5-triphenyl-6-oxoverdazyls 1a-1e were investigated in order to expand the range of synthetic tools for incorporation of the verdazyl system into more complex molecular architectures and to increase spin delocalization. Thus, Pd-catalyzed debenzylation of the OCH2Ph group or basic hydrolysis of the OCOPh group gave the phenol functionality, which was acylated, but could not be alkylated. Orthogonal deprotection of diphenol functionality was also demonstrated in radical 1c. Pt-catalyzed reduction of the NO2 group led to the aniline derivative, which was acylated. Attempted C-C coupling reactions to iodophenyl derivatives 1e and 5e were unsuccessful. Selected verdazyl radicals were characterized by EPR and electronic absorption spectroscopy, and results were analyzed with the aid of DFT computational methods.

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9.4 Hydrazyl and hydrazonyl radicals: R1–N•–NR2R3, R1–N•–N=CR2R3

Neugebauer

Nitrogen and Oxygen Centered Radicals

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Car☐yverdazyls: Water-soluble organic free radicals

Cited by 5 publications

References 4 publications

Association-mediated chromism of amphiphilic triphenyl-6-oxoverdazyl

Association-mediated chromism of amphiphilic triphenyl-6-oxoverdazyl

Functional Group Transformations in Derivatives of 6-Oxoverdazyl

9.4 Hydrazyl and hydrazonyl radicals: R1–N•–NR2R3, R1–N•–N=CR2R3

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