Electron Spin Resonance of the Organic Semiconductor, <i>α</i>-Copper Phthalocyanine

Abkowitz, M.; Chen, Inan; Sharp, J. H.

doi:10.1063/1.1668028

Cited by 32 publications

(19 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The dried products were then further purified by vacuum evaporation for 1 h (10 À5 mbar). CuPc and CuPc F were dissolved in sulfuric acid and in D 2 SO 4 to a concentration of 10 À3 M. CuPc t was dissolved in sulfuric acid, D 2 SO 4 , toluene or toluene-d 8 to a concentration of 10 À3 M. The magnetically diluted compound CuPc : H 2 Pc (1 : 500 weight ratio) was prepared according to Abkowitz et al 11 The sulfuric acid was removed by sublimation and the b-form was isolated. 26,27…”

Section: Experimental Sample Preparationmentioning

confidence: 99%

“…Most EPR investigations on MPcs done so far used continuous wave (cw) EPR. [10][11][12][13][14][15][16][17][18] The results are partially contradictory and many of the magnetic parameters are still not known. During the last two decades, different pulse EPR and electron nuclear double resonance (ENDOR) techniques [19][20][21] have been developed, which allow for a much more detailed investigation of the influences of matrix molecules and ring substituents on the spin-density distribution in these complexes.…”

Section: Introductionmentioning

confidence: 99%

“…In this work, we present a cw and pulse EPR and ENDOR study of the Cu II complexes of Pc, 2,9,16,23-tetra-tert-butyl-29H, 31H-phthalocyanine (Pc t ), and 1,2, 3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H, 31H-phthalocyanine (Pc F ) in various matrices. By means of cw-EPR, hyperfine sublevel correlation 22 (HYSCORE) and Davies-and Mims-ENDOR 23,24 spectroscopy at X-and Q-band 25 frequencies in combination with isotope substitutions, the g values, copper hyperfine couplings and hyperfine interactions of the 14 N, 1 H and 19 F nuclei of the macrocycle and the surrounding matrix molecules are determined and discussed.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Matrix effects on copper(ii)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study

Finazzo

Calle

Stoll

et al. 2006

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The effect of the electron withdrawing or donating character of groups located at the periphery of the phthalocyanine ligand, as well as the influence of polar and nonpolar solvents are of importance for the redox chemistry of metal phthalocyanines. Continuous wave and pulse electron paramagnetic resonance and pulse electron nuclear double resonance spectroscopy at X- and Q-band are applied to investigate the electronic structure of the complexes Cu(II)phthalocyanine (CuPc), copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuPc(t)), and copper(II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine (CuPc(F)) in various matrices. Isotope substitutions are used to determine the g values, the copper hyperfine couplings and the hyperfine interactions with the 14N, 1H and 19F nuclei of the macrocycle and the surrounding matrix molecules. Simulations and interpretations of the spectra are shown and discussed, and a qualitative analysis of the data using previous theoretical models is given. Density functional computations facilitate the interpretation of the EPR parameters. The experimental g, copper and nitrogen hyperfine and nuclear quadrupole values are found to be sensitive to changes of the solvent and the structure of the macrocycle. To elucidate the electronic, structural and bonding properties the changes in the g principal values are related to data from UV/Vis spectroscopy and to density functional theory (DFT) computations. The analysis of the EPR data indicates that the in-plane metal-ligand sigma bonding is more covalent for CuPc(t) in toluene than in sulfuric acid. Furthermore, the out-of-plane pi bonding is found to be less covalent in the case of a polar sulfuric acid environment than with nonpolar toluene or H2Pc environment, whereby the covalency of this bonding is increased upon addition of tert-butyl groups. No contribution from in-plane pi bonding is found.

show abstract

Section: Experimental Sample Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Matrix effects on copper(ii)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study

Finazzo

Calle

Stoll

et al. 2006

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Diese Gleichgewiclite konnten gerade in deiii Bereich der Lanthanidenserie nachgewiesen werden, wo auf Grund thermodynamisdier und kinetischer Untersuchungen [Ill Gleichgewichte der Art (IV) auftreten (Sni, Eu, Gd, Tb) : Ln EDTA(H,O); Ln EDTA(H,O);_, + H,O.Die Zuordnung; der Hoch-und Tieftemperaturbande zum Komplex mit niedrigerer bzw. hiiherer KZ kann mit Hilfe des nephclauxetischen Effektes[19] erfolgen. Danach ergibt sich, class der bei kurzerer Wellenlange absorbierende Komplex (Hochtemperaturmodifikation) von niedriger KZ ist(EuEDTA(H,O);-J.…”

unclassified

Koordinationszahl und nephelauxetischer Effekt von Komplexen der Lanthaniden

Geier

Karlen

Zelewsky

1969

Helvetica Chimica Acta

View full text Add to dashboard Cite

The EuIIIEDTA complex exhibits a strong temperature dependence of its absorption band at 395 nm in dilute aqueous solution. Similar but much weaker effects can be observed in solutions of SmEDTA and GdEDTA, whereas EDTA complexes of the other lanthanide ions as well as the aquo ions of the whole series show no significant change of their absorption spectra in nation number along the series of the lanthanide EDTA complexes that takes place from Sm to Tb at room temperature. It can be concluded from the nephelauxetic effect that the coordination number decreases with increasing atomic number. The coordination numbers of the aquo ions are the same for all trivalent lanthanide ions in dilute solutions.

show abstract

“…The Qband spectra are better resolved showing the axial g anisotropy characteristic of copper (II) phthalocyanine complexes (Figure 4a & 4b). [42][43][44][45][46] The g values are obtained by simulation of the experimental spectra (Table S3). In all the cases, the lowest g deviates significantly from the freeelectron value (ge=2.0023) and g|| is higher than g, thus the unpaired electron is occupying the dx2-y2 orbital in the equatorial plane of a Cu (II) chromophore with elongated tetragonal symmetry.…”

Section: Electron Paramagnetic Resonancementioning

confidence: 99%

Asymmetrically Substituted Phthalocyanines as Dopant-Free Hole Selective Layers for Reliability in Perovskite Solar Cells

Huang

Hernandez

Kazim

et al. 2021

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

Dopant-free metal phthalocyanines are viable alternatives to the classical Spiro-OMeTAD in perovskite solar cells (PSCs), due to their appealing optoelectrical properties and chemical stability. However, low carrier concentration, transportability, and narrow bandgap limit their application. Here, we designed and investigated six innovative asymmetrically substituted metal phthalocyanines (MPcs, M = Zn or Cu), and established the correlation between electronic structure, charge carrier transfer parameter, and core metal/substitutions in MPcs by transient absorbance spectroscopy and electronic paramagnetic resonance. We probed the charge transport properties of ZnPcs including carrier lifetime, diffusion coefficient, and diffusion length by transient absorbance spectroscopy. We noted, ZnPcAE presents a longer diffusion length (1.94 nm) than of control ZnPcTB4 (0.80 nm), which is advantageous for reducing charge recombination and gave higher power conversion efficiency in the fabricated PSCs. Importantly, the devices with MPcs yielded improved stability under multi-stress conditions. Our work provides a molecular guideline for designing MPcs and their application as dopant-free hole-transporting materials for perovskite solar cells fabrication.

show abstract

Electron Spin Resonance of the Organic Semiconductor, α-Copper Phthalocyanine

Cited by 32 publications

References 19 publications

Matrix effects on copper(ii)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study

Matrix effects on copper(ii)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study

Koordinationszahl und nephelauxetischer Effekt von Komplexen der Lanthaniden

Asymmetrically Substituted Phthalocyanines as Dopant-Free Hole Selective Layers for Reliability in Perovskite Solar Cells

Contact Info

Product

Resources

About