Ionic Assembly, Anion–π, Magnetic, and Electronic Attributes of Ambient Stable Naphthalenediimide Radical Ions

Abstract

Organic spin‐based molecular materials are considered to be attractive for the generation of functional materials with emergent optoelectronic, magnetic, or magneto‐conductive properties. However, the major limitations to the utilization of organic spin‐based systems are their high reactivity, instability, and propensity for dimerization. Herein, we report the synthesis, characterization, and magnetic and electronic studies of three ambient stable radical ions (1 a.+, 1 b.+, and 1 c.+). The radical ions 1 b.+ and 1 c.+ with BPh4− and BF4− counter anions, respectively, were synthesized in excellent yields by means of anion metathesis of 1 a.+ with Br− as its counter anion. Notably, synthesis of 1 a.+ was achieved in an ecofriendly, solvent‐free protocol. The radical ions were characterized by means of single‐crystal X‐ray diffraction studies, which revealed the discrete nature of the radical ions and extensive hydrogen‐bonding interactions within the radical ions and with the counter anions. Thus, radical ions can be organized to form infinite supramolecular arrays using weak noncovalent interactions. In addition, the Br−, BF4−, and BPh4− anions formed diverse types of anion–π interactions with the naphthalene and imide rings of the radical ions. The radical ions were characterized by means of X‐band electron paramagnetic resonance (EPR) spectroscopy in solution and in the solid state. Magnetic studies revealed their paramagnetic nature in the range of 10 to 300 K. The radical ions exhibited high resistivity approaching the gigaohm (GΩ) scale. In addition, the radical ions exhibited panchromism.

Naphthalene diimide–Annulated Heterocyclic Acenes: Synthesis, Electrochemical and Semiconductor Properties and their Multifaceted Applications

“…Due to the presence of semiperfluoroalkyl chains, the first reduction potential of ( 69) is observed to be 0.1 less negative than that of the alkyl chain substituted (67). Also the LUMO energy level in case of ( 69) is observed to be lower than both (67)(68). These compounds were also found to be a good candidate for n-type semiconductors and solar cells, owing to their absorption in the whole NIR/visible region.…”

“…Remarkably, (23 a) demonstrates an extraordinarily low LUMO level of À 5.15 eV, solidifying its position as the arylenediimide with the lowest LUMO. [67][68][69] The versatility of NDI extends to biology, where its fluorescence properties have been leveraged for biological imaging and sensing. [70,71] Basak et al synthesised an NDI-based peptide which has potential applications in authentication tools for security purposes and encryption of information.…”

Truxenone Triimide: Two‐Dimensional Molecular Arrangements of Triangular Molecules for Air Stable n‐Type Semiconductors

“…The rational design and synthesis of highly electron deficient π‐conjugated organic materials have received tremendous attention owing to their potential application as n‐type organic semiconductors in the fabrication of next generation flexible opto‐electronic devices, such as organic field‐effect transistors (OFETs), [ 1,2 ] organic light‐emitting diodes (OLEDs), [ 3–5 ] and organic photovoltaics (OPVs). [ 6–8 ] In addition, these molecules have found wide ranging applications in anion‐π‐interactions, [ 9,10 ] anion‐π catalysis, [ 11,12 ] anion transport across the cell membrane, [ 13,14 ] and in preparation of organic magnetic [ 15–18 ] and direduced materials. [ 19 ] Despite their intrinsic potential in the development of complementary circuits, non‐fullerene n‐type materials lag far behind compared to their counterpart p‐type materials in terms of molecular diversity, air stability, and carrier mobility.…”

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cell membrane, [13,14] and in preparation of organic magnetic [15][16][17][18] and direduced materials. [19] Despite their intrinsic potential in the development of complementary circuits, non-fullerene n-type materials lag far behind compared to their counterpart p-type materials in terms of molecular diversity, air stability, and carrier mobility.

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Perhalogenated Tetraazaperopyrenes and Their Corresponding Mono- and Dianions

“…The design and synthesis of organic materials with electron-accepting properties which perform satisfactorily as electron (n-channel) semiconductors remains a challenging task. − Promising strategies are based on the isosteric CH → N-substitution within the organic framework − and the introduction of electron-withdrawing groups, − which both lead to significant stabilization of frontier orbitals. Low-lying lowest unoccupied molecular orbitals (LUMOs) in particular are a prerequisite for the application as n-channel semiconductors by decreasing the electron-injection barrier at the interface between the active layer and the electrodes. , Additionally, they stabilize the reduced species, making it even possible to isolate and characterize these under certain conditions. − …”