Electronic absorption spectra and dipole moments for hydrazyl radicals

Gubanov, V. A.; Pereliaeva, L. A.; Chirkov, A. K.; Matevosian, R. O.

doi:10.1007/bf00527332

Cited by 7 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…N(19)-C(1) has a still smaller value (1.37 A). Gubanov, Pereliaeva, Chirkov & Matevosian (1970) have calculated bond orders for DPPH [0.436 for N-N, 0.369 for N-C(phenyl) and 0.513 for N-C(picryl)], but they assume that the molecule is planar and that N(19) has ~p hydridization. Their results are therefore not applicable to the DPPH molecules in the crystals, where smaller bond orders are expected due to the non-planarity of the molecules and sp z hybridization at N(19).…”

Section: N-c Bondsmentioning

confidence: 99%

The crystal structure of a 2,2-diphenyl-1-picrylhydrazyl (DPPH) modification

Kiers¹,

Boer²,

Olthof³

et al. 1976

Acta Crystallogr Sect B

View full text Add to dashboard Cite

Section: N-c Bondsmentioning

confidence: 99%

The crystal structure of a 2,2-diphenyl-1-picrylhydrazyl (DPPH) modification

Kiers¹,

Boer²,

Olthof³

et al. 1976

Acta Crystallogr Sect B

View full text Add to dashboard Cite

“…Gubanov et al improved on the previous calculations slightly by starting off with a semiempirical self-consistent field (SCF) linear combination of atomic orbital (LCAO) method. 35 However, the calculations were performed assuming that the DPPH • radical was planar. 11 No theoretical geometry optimizations were carried out and the atomic coordinates were not taken from the existing X-ray single crystal structure data.…”

Section: Introductionmentioning

confidence: 99%

“…Due to the approximate semiempirical nature of this method, no reliable correlations with the experimental properties and spectra could be made. Gubanov et al improved on the previous calculations slightly by starting off with a semiempirical self-consistent field (SCF) linear combination of atomic orbital (LCAO) method . However, the calculations were performed assuming that the DPPH • radical was planar .…”

Section: Introductionmentioning

confidence: 99%

Role of the Geometry, Restricted Rotations and Solvents on the Computed 2,2′-Diphenyl-1-picrylhydrazyl Hyperfine Tensors

Mattar

Sanford

2008

J. Phys. Chem. A

View full text Add to dashboard Cite

The nuclear hyperfine tensor (A) components of the 2,2'-diphenyl-1-picrylhydrazyl neutral radical are computed using the UB1LYP hybrid density functional method. Solvent interactions via hydrogen bonding are found to play a crucial role in the position of the two phenyl rings relative to the picryl moiety. Under these conditions, the calculated isotropic hyperfine tensor components of the N 1 and N 2 hydrazyl backbone are within approximately 1.3 Gauss (G) of the experimental values determined by EPR and ENDOR spectroscopy. Just as important are the effects of restricted rotations of the phenyl rings on these tensors. Rotational averaging using a Maxwell-Boltzmann type distribution improves the agreement between theory and experiment to less than 1.0 G. In addition, rotational averaging of the twelve isotropic proton coupling constants has also been performed. They come within 0.3 G of the experimental values. Thus, for the first time, all the nuclear hyperfine tensor components of this large class of molecules are accurately calculated without resorting to post Hartree-Fock techniques.

show abstract

“…The DPPH NPs have absorption bands in the UV and visible regions [I and II, respectively] (Figure d). These two bands originate from π−π* transitions of DPPH radicals, and the delocalized radical electron makes a major contribution to II . Both of the NP absorption bands exhibit a size-dependent red shift relative to free DPPH molecules in THF: the bigger the NPs, the larger the red shift, and vice versa (Figure d inset and Figures S2 and S3).…”

mentioning

confidence: 97%

“…These two bands originate from π-π* transitions of DPPH radicals, and the delocalized radical electron makes a major contribution to II. 8 Both of the NP absorption bands exhibit a size-dependent red shift relative to free DPPH molecules in THF: the bigger the NPs, the larger the red shift, and vice versa (Figure 1d inset and Figures S2 and S3). The red shift of these π-π* absorption bands is due to J-type aggregation of DPPH molecules inside an NP.…”

mentioning

confidence: 99%

Synthesis of Water-Soluble 2,2′-Diphenyl-1-Picrylhydrazyl Nanoparticles: A New Standard for Electron Paramagnetic Resonance Spectroscopy

et al. 2009

View full text Add to dashboard Cite

This communication reports a size-controlled synthesis of water-soluble 2,2'-diphenyl-1-picrylhydrazyl (DPPH) nanoparticles (NPs). These nanoparticles exhibit size-dependent absorption spectra and fast spin exchange-narrowed single-line EPR spectra. The linewidths of the EPR spectra of these water-soluble nanoparticles are approximately 1.5-1.8 G, which are equal or close to the narrowest line width (1.5 G) of the common DPPH standard in the form of water-insoluble microcrystals. In addition, these NPs are stable over a wide pH range of 3.0 to 10.0. These properties make these water-soluble DPPH NPs suitable for use as a new type of EPR standard, which is important for fundamental research and practical applications in fields such as the food industry and the life sciences. Furthermore, the DPPH NPs can potentially be used as a spin probe in biomedical studies.

show abstract

Electronic absorption spectra and dipole moments for hydrazyl radicals

Cited by 7 publications

References 9 publications

The crystal structure of a 2,2-diphenyl-1-picrylhydrazyl (DPPH) modification

The crystal structure of a 2,2-diphenyl-1-picrylhydrazyl (DPPH) modification

Role of the Geometry, Restricted Rotations and Solvents on the Computed 2,2′-Diphenyl-1-picrylhydrazyl Hyperfine Tensors

Synthesis of Water-Soluble 2,2′-Diphenyl-1-Picrylhydrazyl Nanoparticles: A New Standard for Electron Paramagnetic Resonance Spectroscopy

Contact Info

Product

Resources

About