Raman Spectroscopy Shows Interchain through Space Charge Delocalization in a Mixed Valence Oligothiophene Cation and in Its π-Dimeric Biradicaloid Dication

Casado, Juan; Takimiya, Kazuo; Otsubo, Tetsuo; Ramı́rez, Francisco J.; Quirante, J.J.; Ortiz, Rocío Ponce; González, Serafín Vegas; Oliva, María Moreno; Navarrete, Juan T. López

doi:10.1021/ja806207j

Cited by 37 publications

(32 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spectral changes monitored upon the chemical oxidation were reproduced after rapid (potential-step) electrochemical oxidation of D4T7 in the high-concentration regime However, the more bulky Bu 4 N[B(C 6 F 5 ) 4 ] electrolyte causes somewhat slower conversion of the transient species T1 and the radical cation to the p-dimer dication (see Figure S2 in the Supporting Information); that is, the weakly coordinating B(C 6 F 5 ) 4 À anions stabilize D4T7C + to a greater extent. However, the effect of the counterion nature and size seems to be less pronounced in the experiments performed at high concentrations of D4T7 (!…”

Section: Resultsmentioning

confidence: 99%

Multistep π Dimerization of Tetrakis(n‐decyl)heptathienoacene Radical Cations: A Combined Experimental and Theoretical Study

Ferrón

Capdevila‐Cortada

Balster

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

Radical cations of a heptathienoacene α,β-substituted with four n-decyl side groups (D4T7(.) (+) ) form exceptionally stable π-dimer dications already at ambient temperature (Chem. Comm. 2011, 47, 12622). This extraordinary π-dimerization process is investigated here with a focus on the ultimate [D4T7(.) (+) ]2 π-dimer dication and yet-unreported transitory species formed during and after the oxidation. To this end, we use a joint experimental and theoretical approach that combines cyclic voltammetry, in situ spectrochemistry and spectroelectrochemistry, EPR spectroscopy, and DFT calculations. The impact of temperature, thienoacene concentration, and the nature and concentration of counteranions on the π-dimerization process is also investigated in detail. Two different transitory species were detected in the course of the one-electron oxidation: 1) a different transient conformation of the ultimate [D4T7(.) (+) ]2 π-dimer dications, the stability of which is strongly affected by the applied experimental conditions, and 2) intermediate [D4T7]2 (.) (+) π-dimer radical cations formed prior to the fully oxidized [D4T7]2 (.) (+) π-dimer dications. Thus, this comprehensive work demonstrates the formation of peculiar supramolecular species of heptathienoacene radical cations, the stability, nature, and structure of which have been successfully analyzed. We therefore believe that this study leads to a deeper fundamental understanding of the mechanism of dimer formation between conjugated aromatic systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Multistep π Dimerization of Tetrakis(n‐decyl)heptathienoacene Radical Cations: A Combined Experimental and Theoretical Study

Ferrón

Capdevila‐Cortada

Balster

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…However, polar solvents tend to destabilize radical cations in the solution phase, and most studies of π‐dimer‐based supramolecular chemistry are conducted in dichloromethane 5. 6, 12a–d, 13, 21, 22 Therefore, to shed some light on the driving forces for the π‐dimerization in dichloromethane solution, we considered the following four factors: 1) SOMO–SOMO interactions, 2) van der Waals forces, 3) solvation, and 4) Coulomb repulsion. We will discuss each factor in detail.…”

Section: Discussionmentioning

confidence: 99%

Steric Control in the π‐Dimerization of Oligothiophene Radical Cations Annelated with Bicyclo[2.2.2]octene Units

Tateno

Takase

Iyoda

et al. 2013

Chemistry A European J

View full text Add to dashboard Cite

A Two series of oligothiophenes 2(nT) (n=4,5), annelated with bicyclo[2.2.2]octene (BCO) units at both ends, and quaterthiophenes 3 a-c, annelated with various numbers of BCO units at different positions, were newly synthesized to investigate the driving forces of π-dimerization and the structure-property relationships of the π-dimers of oligothiophene radical cations. Their radical-cation salts were prepared through chemical one-electron oxidation by using nitrosonium hexafluoroantimonate. From variable-temperature electron spin resonance and electronic absorption measurements, the π-dimerization capability was found to vary among the members of the 2(nT)(+)(·)SbF6(-) series and 3(+)(·)SbF6(-) series of compounds. To examine these results, density functional theory (DFT) calculations at the M06-2X/6-31G(d) level were conducted for the π-dimers. This level of theory was found to successfully reproduce the previously reported X-ray structure of (2(3T))2(2+) having a bent π-dimer structure with cis-cis conformations. The absorption bands obtained by time-dependent DFT calculations for the π-dimers were in reasonable agreement with the experimental spectra. The attractive and repulsive forces for the π-dimerization were divided into four factors: 1) SOMO-SOMO interactions, 2) van der Waals forces, 3) solvation, and 4) Coulomb repulsion, and the effects of each factor on the structural differences and chain-length dependence are discussed in detail.

show abstract

“…Casado et al. prepared pentathiophene‐incorporated macrocycle 22 78. The two oligothiophene units could also undergo one‐electron oxidation to afford two stable radical cations.…”

Section: Stabilization Of Radical Cation Dimers In a Confined Envimentioning

confidence: 99%

Engineering Dendritic Aptamer Assemblies as Superior Inhibitors of Protein Function

Kim

Dennis

Morey

et al. 2009

Chemistry An Asian Journal

View full text Add to dashboard Cite

show abstract

Raman Spectroscopy Shows Interchain through Space Charge Delocalization in a Mixed Valence Oligothiophene Cation and in Its π-Dimeric Biradicaloid Dication

Cited by 37 publications

References 16 publications

Multistep π Dimerization of Tetrakis(n‐decyl)heptathienoacene Radical Cations: A Combined Experimental and Theoretical Study

Multistep π Dimerization of Tetrakis(n‐decyl)heptathienoacene Radical Cations: A Combined Experimental and Theoretical Study

Steric Control in the π‐Dimerization of Oligothiophene Radical Cations Annelated with Bicyclo[2.2.2]octene Units

Engineering Dendritic Aptamer Assemblies as Superior Inhibitors of Protein Function

Contact Info

Product

Resources

About