Charge Transfer Modulated Self-Assembly in Poly(aryl ether) Dendron Derivatives with Improved Stability and Transport Characteristics

Abstract

Alteration of native gelation properties of anthracene and pyrene cored first generation poly(aryl ether) dendrons, G1-An and G1-Py, by introducing a common acceptor, 2,4,7-trinitro-9H-fluoren-9-one (TNF), results in forming charge transfer gels in long chain alcoholic solvents. This strategy leads to significant perturbation of optical and electronic properties within the gel matrix. Consequently, a noticeable increase of their electrical conductivities is observed, making these poly(aryl ether) dendron based gels potential candidates for organic electronics. While the dc-conductivity (σ) value for the native gel from G1-An is 2.8 × 10 S m, the value increased 3 times (σ = 8.7 × 10 S m) for its corresponding charge transfer gel. Further, the dc-conductivity for the native gel self-assembled from G1-Py dramatically enhanced by approximately an order of magnitude from 4.9 × 10 to 1.3 × 10 S m, under the influence of an acceptor. Apart from H-bonding and π···π interactions, charge transfer results in the formation of a robust 3D network of fibers, with improved aspect ratio, providing high thermo-mechanical stability to the gels compared to the native ones. The charge transfer gels self-assembled from G1-An/TNF (1:1) and G1-Py/TNF exhibit a 7.3- and 2.5-fold increase in their yield stress, respectively, compared to their native assemblies. A similar trend follows in the case of their thermal stabilities. This is attributed to the typical bilayer self-assembly of the former which is not present in the case of G1-Py/TNF charge transfer gel. Density functional calculations provide deeper insights accounting for the role of charge transfer interactions in the mode of self-assembly. The 1D potential energy surface for the G1-An/TNF dimer and G1-Py/TNF dimer is found to be 11.8 and 1.9 kcal mol more stable than their corresponding native gel dimers, G1-An/G1-An and G1-Py/G1-Py, respectively.

Effect of Slip‐Stack Self‐Assembly on Aggregation‐Induced Emission and Solid‐State Luminescence in 1,3‐Diarylpropynones

“…Additional support behind this interaction came from the long‐range diffraction peak, in powder XRD analysis of PYNAP (Figure S13). The notable reflection peak, appeared at 2θ=25.01°, indexed a d‐spacing of 3.57 Å and confirmed the presence of this intermolecular π⋅⋅⋅π interaction . On the other hand, obvious flipping of naphthalene unit around the single bond, connected with keto group, caused a certain amount of twisting in the structure.…”

Augmenting Photoinduced Charge Transport in a Single‐Component Gel System: Controlled In Situ Gel–Crystal Transformation at Room Temperature

“…The peripheral o ‐benzoxy rings of PAE dendrons now become strongly electronegative in character, with respect to the central N atom of the TPA core. The stability of such highly polarized states of TPAPAE ⋅+ can ameliorate the conduction pathways in a single‐component molecular assembly, without the need of any dopants/additives . However, prohibiting deactivation of such states is difficult, which demands for a higher order assembly.…”

“…The stability of such highly polarized states of TPAPAE · + can ameliorate the conduction pathways in as ingle-component molecular assembly,w ithout the need of any dopants/additives. [44] However,p rohibiting deactivation of such states is difficult, whichd emands for ah igher order assembly.T he self-assembled nanocrystalse xhibit tremendous electrochemical stabilization of TPAPAE mixed valence states, upon applying electrical voltage. Cyclic voltammograms (CV) for the xerogel-coated electrodes show ah igh stabilization of mixed valence states,w ith an onset of two irreversible oxidation potentials at E ox 1 = 0.34 V and E ox 2 = 0.46 V, (Figure S13 a) corresponding to TPAPAE · + and TPAPAE ·2 + ,r espectively.T he irreversiblee lectrochemical stability of the charge carriers is retained even after 20 cycles.T his is in contrastt ot he reversible redox response of solidT PAPAE, which showss table and reversible redox responsea tasimilar potentialw ith lower current (Figure S13 b).…”

“…The high photoconductivity value from such single-component self-assembled ordered crystals, neither using ad onor-acceptor or I 2 doping strategy nor compromising their emission features, are impressive with respect to reported values. [6,7,10,[44][45][46]…”

Computational Designing of Low Energy Gap Small Molecule Acceptors for Organic Solar Cells

“…Arago et al, [47,48] have performed the benchmark studies using wB97X-D functional against several dispersion-corrected hybrids and highly correlated methods. They found that the wB97X-D exhibits the best performance to deal with charge-transfer excitations in a balanced way.…”