Establishing design principles to create nonplanar π-conjugated molecules is crucial for the development of novel functional materials. Herein, we describe the synthesis and properties of dinaphtho­[1,8-bc:1′,8′-ef]­azepine bisimides (DNABIs). Their molecular design is conceptually based on the insertion of a nitrogen atom into a perylene bisimide core. We have synthesized several DNABI derivatives with a hydrogen atom, a primary alkyl group, or an aryl group on the central nitrogen atom. These DNABIs exhibit nonplanar conformations, flexible structural changes, and ambipolar redox activity. The steric effect around the central nitrogen atom substantially affects the overall structures and results in two different conformations: a nonsymmetric bent conformation and a symmetric twisted conformation, accompanied by a drastic change in electronic properties. Notably, the nonsymmetric DNABI undergoes unique structural changes in response to the application of an external electric field, which is due to molecular motions that are accompanied by an orientational fluctuation of the dipole moment. Furthermore, the addition of a chiral Brønsted base to N-unsubstituted DNABI affords control over the helical chirality via hydrogen-bonding interactions.

Polar H 2 O molecules generally act as trapping sites and suppress the electron mobility of n-type organic semiconductors, making chemical design of H 2 O-tolerant and responsive n-type semiconductors an important step toward multifunctional electron−ion coupling devices. The introduction of effective electrostatic interactions between potassium ions (K + ) and carboxylate (−COO − ) anions into the electron-transporting naphthalenediimide πframework enables the design of high-performance H 2 O-tolerant n-type semiconductors with a reversible H 2 O adsorption−desorption ability, where the electron mobility and K + ionic conductivity were coupled with the reversible H 2 O sorption behavior. The reversible H 2 O adsorption into the crystals enhanced the electron mobility from 0.04 to 0.28 cm 2 V −1 s −1 , whereas the K + ionic conductivity decreased from 3.4 × 10 −5 to 4.7 × 10 −7 S cm −1 . Because this reversible electron−ion conducting switch is responsive to H 2 O sorption behavior, it is a strong candidate for H 2 O gating carrier transport systems.

Electrostatic cation–anion interaction is effective to form a tightly bounded π-molecular assembly, which enhances the thermal stability and carrier transport property. Dianionic bis­(benzenesulfonate)–naphthalenediimide (BSNDI 2– ) formed simple 2:1 cation–anion pairs of (Na+)2(BSNDI 2– ) (1), (K+)2(BSNDI 2– ) (2), and (NH4 +)2(BSNDI 2– ) (3), and their redox behaviors, thermal stabilities, crystal structures, electron transport properties, and dielectric constants were compared to those of neutral bis­(phenyl)–naphthalenediimide (4). Crystals 1, 2, and 3 had quite high thermal stabilities up to 850, 810, and 600 K, respectively, even though organic molecules. A two-dimensional (2D) n-type electron transport layer consisting of NDI π cores was sandwiched between networks of highly polarized electrostatic cation–anion pairs showing 2D herringbone (1), one-dimensional π-stacking (2), and brickstone-like 2D π-stacking (3) interactions. The values of electron mobility in polycrystalline 1, 2, 3, and 4 reached 0.22, >0.0003, 0.036, and >0.028 cm2 V–1 s–1, respectively, according to flash-photolysis time-resolved microwave conductivity measurements. The electron mobility of crystal 1 was 1 order of magnitude higher than those of crystals 2, 3, and 4 owing to the tight intermolecular interactions within the 2D transport layer. The real part dielectric constants of crystals 1, 2, 3, and 4 were ∼4, ∼50, ∼20, and ∼4 at 450 K, respectively, which affected the electron transport property. The chemical design of highly polarized electrostatic cation–anion pair formed the 2D transport layer and also has high thermal stability up to ∼850 K in the ionic n-type semiconducting materials.

Hydrophilic fullerene derivatives of C60(OH)12 (1) and C60(OH)36 (2) bearing different numbers of-OH groups formed amorphous solids of 1•x(H2O) (x = 5-10) and 2•x(H2O) (x = 15-22), respectively, according to the humidity. The thermally activated dynamic molecular motion of polar H2O was confirmed in the DSC and dielectric spectra. Three-dimensional O-H•••O hydrogen-bonding networks in amorphous 1 and 2 produced extrinsic adsorption-desorption pores with a hydrophilic environment posed by-OH groups, where N2, CO2, H2, and CH4 gases vapors and polar H2O, MeOH, and EtOH molecules reversibly adsorbed into the networks. Molecular motion of polar H2O was directly observed in dielectric enhancement and protonic conductivity in three-dimensional O-H•••O hydrogen-bonding networks. The Brunauer-Emmett-Teller (BET) specific surface areas of amorphous 1 and 2 were 315 and 351 m 2 g-1 , respectively, from the CO2 sorption isotherms. Reversible vapor sorption behaviors with structural changes of amorphous 1 and 2 were also confirmed for the polar H2O, MeOH, and EtOH.

which exhibited reversible H 2 O adsorption−desorption behavior because of the presence of their electrostatically binding crystal lattices. The maximum H 2 O adsorption amounts (n) for M + = Li + , Na + , K + , Rb + , and Cs + were 0.25, 6.0, 4.0, 6.0, and 2.0, respectively, whereas the reversible gate-opening (gateclosing) H 2 O adsorption−desorption isotherms were observed at 273 and 298 K, except for M + = Li + . High ionic conductivities of around 10 −4 −10 −5 S cm −1 were observed in M + = Na + and K + salts, whereas short-range thermal fluctuations occurred in large cations of M + = Rb + and Cs + . The change in the electrostatic lattice energy for M + = Na + and K + salts during the H 2 O adsorption−desorption cycles was significantly larger than those for M + = Rb + and Cs + . Therefore, the Na + and K + salts had a considerably flexible electrostatic crystal lattice with a large amplitude of lattice modulation during the H 2 O sorption cycle. In contrast, the lattice modulation for M + = Rb + and Cs + salts involved a low magnitude of ion displacements, forming a relatively rigid cation−anion electrostatic crystal lattice. The flash-photolysis time-resolved microwave conductivity and transition absorption spectroscopy results revealed the high electron mobility of H 2 O-adsorbed thin films, wherein the crystallized H 2 O molecules did not act as electron-trapping sites. The values of electron mobility increased in the order of Cs