Fingerprints for Structural Defects in Poly(thienylene vinylene) (PTV): A Joint Theoretical–Experimental NMR Study on Model Molecules

Diliën, Hanne; Marin, Lidia; Botek, Edith; Champagne, Benoı̂t; Lemaur, Vincent; Beljonne, David; Lazzaroni, Roberto; Cleij, Thomas J.; Maes, Wouter; Lutsen, Laurence; Vanderzande, Dirk; Adriaensens, Peter

doi:10.1021/jp206663v

Cited by 8 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A joint experimental–theoretical study of the 1 HNMR chemical shift assignment in thiophene‐based polymers has been recently found to be interesting for the identification of the structural defects, end‐groups and regioregularity 18. Figure 6 compares the experimental 1 H NMR spectrum of B3T and the DFT‐calculated 1 H chemical shifts.…”

Section: Results Ad Discussionmentioning

confidence: 99%

Conformational Control of the Electronic Properties of an α‐β Terthiophene: Lessons from a Precursor Towards Dendritic Hyperbranched Oligo‐ and Poly‐Thiophenes

González-Cano¹,

Herrera²,

Segura³

et al. 2012

ChemPhysChem

View full text Add to dashboard Cite

Herein we investigate the conformational and electronic properties of the 2,2';3',2"-terthiophene (B3T) unit as the building block of thiophene dendrimeric materials. By means of DFT ground electronic state dihedral energy profiles, we get insight in the flexibility of B3 T as the prominent feature promoting the 3D arrangement. The presence of diverse conformers is explored by Raman and (1)H NMR spectroscopies. A theoretical estimation of the Raman and (1)H NMR spectra over the most energetically accessible conformers is found to be crucial for the appropriate assignment of the major conformer population derived from the experimental spectra. We show that energy barriers for the interconversion of conformers also play a role. Finally, the impact on the optical spectra (absorption and emission) of the α-α and α-β connections is studied and addressed by scanning the properties of the relevant low-lying excited states. These studies highlight the relevance of the architecture of the basic molecular unit to understand charge and exciton behavior in organic semiconductors, particularly for those useful in photovoltaics.

show abstract

Section: Results Ad Discussionmentioning

confidence: 99%

Conformational Control of the Electronic Properties of an α‐β Terthiophene: Lessons from a Precursor Towards Dendritic Hyperbranched Oligo‐ and Poly‐Thiophenes

González-Cano¹,

Herrera²,

Segura³

et al. 2012

ChemPhysChem

View full text Add to dashboard Cite

show abstract

“…Then, the isotropic shielding constants were evaluated using the B3LYP XC functional and the 6-311+G(2d,p) basis set in combination with the GIAO method . This approach was already employed and its performance substantiated in ref . Then, the chemical shifts were evaluated as δ = σ ref – σ, where σ ref is the shielding constant of 1 H of tetramethylsilane (TMS) as reference compound.…”

Section: Methodsmentioning

confidence: 99%

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

et al. 2018

View full text Add to dashboard Cite

Density functional theory calculations are used to reveal the relationships between the structures, energies, and NMR signatures of an octastate molecular switch composed of a dithienylethene (DTE) unit covalently linked to an indolino[2,1-b]oxazolidine (BOX) moiety through an ethylenic junction. Both the DTE and BOX moieties can adopt open or closed forms. The ethylenic junction can be Z or E, but the latter has been confirmed to be, by far, more stable than the former for all BOX/DTE combinations. In addition, when the DTE is open, the two thienyl units can fold to form parallel conformers, by opposition to the antiparallel or unfolded conformers. Usually parallel conformers present a higher energy than the antiparallel ones, but in the case of compound 2 having a bulky substituent (R = pPh-SMe) on the terminal thienyl group, the enthalpy of one conformer is very close (1–2 kJ mol–1) to that of the most stable antiparallel one, making photocyclization less efficient. These conformational differences and the presence of parallel DTE forms have been substantiated by analyzing experimental 1H NMR chemical shifts in light of their calculated values. These 1H NMR chemical shift calculations led to the following statements: (i) Going from state I (DTE open, BOX closed) to state II (both DTE and BOX are open) the H8 proton of compound 1 (R = Me) is deshielded by ∼0.15 ppm. (ii) The deshielding of H8 proton of compound 2 is larger and attains 0.41 ppm whereas H7 is more shielded by 0.11 ppm. (iii) Then, going from compound 1 to compound 2 leads to deshielding of both H7 and H8 protons. As a consequence, the difference of photochromism gating efficiency among compounds 1, 2, and 3 (R = pPh-OMe) can be attributed to the stabilization of parallel conformer due to an establishment of an intramolecular interaction with BOX opening.

show abstract

Combined experimental–theoretical NMR study on 2,5‐bis(5‐aryl‐3‐hexylthiophen‐2‐yl)‐thiazolo[5,4‐d]thiazole derivatives for printable electronics

Mierloo

Liégeois

Kudrjašova

et al. 2012

Magnetic Reson in Chemistry

Self Cite

View full text Add to dashboard Cite

Four 2,5-bis(5-aryl-3-hexylthiophen-2-yl)thiazolo[5,4-d]thiazole derivatives have been synthesized and thoroughly characterized. The extended aromatic core of the molecules was designed to enhance the charge transport characteristics, and solubilizing hexyl side chains were introduced on the thiophene subunits to enable possible integration of these semiconducting small molecules in printable electronics. Complete elucidation of the chemical structures by detailed one-dimensional/two-dimensional NMR spectroscopy is described, providing interesting input for chemical shift prediction software as well, because limited experimental data on these types of compounds are currently available. Furthermore, theoretical calculations have assisted experimental observations--giving support for the chemical shift assignment and providing a springboard for future screening and predictions--demonstrating the benefits of a coordinated theoretical-experimental approach.

show abstract

Fingerprints for Structural Defects in Poly(thienylene vinylene) (PTV): A Joint Theoretical–Experimental NMR Study on Model Molecules

Cited by 8 publications

References 43 publications

Conformational Control of the Electronic Properties of an α‐β Terthiophene: Lessons from a Precursor Towards Dendritic Hyperbranched Oligo‐ and Poly‐Thiophenes

Conformational Control of the Electronic Properties of an α‐β Terthiophene: Lessons from a Precursor Towards Dendritic Hyperbranched Oligo‐ and Poly‐Thiophenes

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

Combined experimental–theoretical NMR study on 2,5‐bis(5‐aryl‐3‐hexylthiophen‐2‐yl)‐thiazolo[5,4‐d]thiazole derivatives for printable electronics

Contact Info

Product

Resources

About

Fingerprints for Structural Defects in Poly(thienylene vinylene) (PTV): A Joint Theoretical–Experimental NMR Study on Model Molecules

Cited by 8 publications

References 43 publications

Conformational Control of the Electronic Properties of an α‐β Terthiophene: Lessons from a Precursor Towards Dendritic Hyperbranched Oligo‐ and Poly‐Thiophenes

Conformational Control of the Electronic Properties of an α‐β Terthiophene: Lessons from a Precursor Towards Dendritic Hyperbranched Oligo‐ and Poly‐Thiophenes

Assessing the Structure of Octastate Molecular Switches Using 1H NMR Density Functional Theory Calculations

Combined experimental–theoretical NMR study on 2,5‐bis(5‐aryl‐3‐hexylthiophen‐2‐yl)‐thiazolo[5,4‐d]thiazole derivatives for printable electronics

Contact Info

Product

Resources

About

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations