Stable room temperature ferroelectricity in hydrogen-bonded supramolecular assemblies of ambipolar π-systems

Abstract

This article reports H-bonding driven supramolecular polymerization of naphthalimide(A)-thiophene(D)-naphthalimide(A) (ADnA, n = 1-4) conjugated ambipolar π-systems and its remarkable impact on the room temperature ferroelectricity. Electrochemical studies confirm the ambipolar...

A Hierarchical (Macro)molecular Assembly Assisted by Donor–Acceptor Charge‐Transfer Interactions Exhibiting Room‐Temperature Ferroelectricity

“…Moreover, the distribution of points around the anomaly follows the Curie-Weiss law as it shows a distinct deflection in 1/ɛ r values (Figure 5c) around the plausible T c , [3,21] suggesting a possible ferroelectric to paraelectric transition, also seen in other soft FE-materials. [1][2][3][4][5]22] The anomaly peak remains unchanged with frequency within the measured temperature range, which further supports a ferroelectric to paraelectric state by ruling out the presence of any relaxor behaviour in this system. [21b] and furthermore shows a low dielectric loss (Figure S16).…”

“…[2] Although, Rochelle salt was reported in 1920, [3] purely organic FE-systems with appreciable polarization are still limited to only a few examples. [4,5] Supramolecular assembly may be an attractive approach for soft ferroelectrics, [4c] because in one hand it enables directional orientation of the intrinsically polarizable monomer to generate a macro-dipole, while on the other hand its dynamics may help in electrically reversible polarization, a pre-requisite for realizing ferroelectricity. In this context donor(D)-acceptor(A) charge transfer (CT)complexes [6] have gained significant attention following recent invention on room temperature (rt) ferroelectricity in their H-bonded co-crystals [7] or gel.…”

Charge Separation and Intersystem Crossing in Homo- and Hetero-Compact Naphthalimide Dimers

“…NI is a chromophore widely used in fluorescence molecular probes, , supramolecular assemblies, , and fundamental photochemistry studies, such as ISC and phosphorescence. − Previously, NI dimers with long and flexible linkers between the two NI units were reported, and the formation of a singlet excimer was observed, but no compact NI dyads were reported to study the SBCT and the associated ISC. A rigid NI dimer connected at 4-position by a diacetylene linker was reported as an electron acceptor for photovoltaic studies, but the detailed photophysical properties were not studied …”

“…Molecular Structure Design Rationales. NI is a chromophore widely used in fluorescence molecular probes, 66,67 supramolecular assemblies, 68,69 and fundamental photochemistry studies, such as ISC and phosphorescence. 70−72 Previously, NI dimers with long and flexible linkers between the two NI units were reported, and the formation of a singlet excimer was observed, 73 but no compact NI dyads were reported to study the SBCT and the associated ISC.…”

Ferroelectricity in a hydrogen-bonded alternating donor–acceptor supramolecular copolymer

“…Organic ferroelectric (FE) materials, 1 despite exhibiting relatively lower magnitude of polarization compared to the benchmark inorganic or hybrid systems, 2 have been studied with interest as they may offer new opportunities for environmentally-benign, solution-processed, flexible device fabrication. Amongst different organic FE-systems, 3 charge-transfer (CT) complexes 4 of aromatic donor (D) and acceptor (A) chromophores appear highly promising, especially after the recent breakthrough on room-temperature ferroelectricity in D–A co-crystals or other co-assembled systems. 5 These inspiring results have motivated the search for new D–A co-assembled systems, such as supramolecular polymers with adjustable physical and chemical properties to broaden the scope of such emerging organic materials.…”