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• Exhaustive photochromic, dielectric and electrochemical analysis of an azobenzene-based organic compound, tAZOi. • tAZOi assembles into molecular dimers by hydrogen-bonding between thymine heads. • An ITO/tAZOi/Al device presents two switchable conductance states with preservation of memory performance. • Conductivity in the transition between ground and excited states is p-type, involving hydrogen-bonded thymine heads. • tAZOi increases dielectric permittivity driven by trans-to-cis isomerisation of the azobenzene groups upon UV irradiation. • Molecular simulations suggest that device performance can be enhanced by light exposure. In the search to obtain new and more efficient components of memory devices, we report the photochromic, dielectric and electrochemical response of a light-responsive organic compound, and its memory performance under electrical fields. The so-called N(1)-[12-(4-(4′-isobutyloxyphenyldiazo)phenoxy)dodecyloxy)]thymine, tAZOi, molecule contains one azobenzene group, which provides with photochromic character, and one terminal thymine group, capable to form hydrogen bonds and assemble supramolecular dimers, (tAZOi) 2. We have calculated the optical absorption coefficient, extinction coefficient and refractive index of tAZOi, which obeys the single oscillator Wemple–DiDomenico model. An ITO/tAZOi/Al device has been prepared and presents two switchable conductance states with preservation of memory performance. The mechanism linked to the resistive random-access memory (RRAM) has been evaluated by molecular modelling and is controlled by p-type conduction, possibly involving hydrogen-bonding. Upon UV irradiation at ∼ 365 nm, tAZOi displays an increase in the complex permittivity driven by trans -to- cis (E -to- Z) isomerisation of the azobenzene groups. Molecular simulations suggest that conductivity and device performance can be enhanced (and controlled) by light exposure through the formation of activated Z isomers that could transfer charge to other neighbouring molecules, resulting in photo-electric responsive devices. [ABSTRACT FROM AUTHOR]

• Synthesis of new side-chain liquid crystalline copolymers containing polarisable groups. • Azobenzene groups confer light-responsive character to the electrolytes. • Electro-donating and electro-withdrawing groups tailor molecular structure. • High conductivity values are reached (10–2.9 S·cm−1) under anhydrous conditions. • Ion conductivity occurs through nematic and smectic phases, decoupled from the polymer backbone. We have prepared and characterised a series of side-chain liquid crystalline homopolymers and terpolymers containing different azobenzene derivatives (R AzB), sulfonic groups (2-acrylamido-2-methyl-1-propanesulfonic acid, AMPS), and methyl(methacrylate) groups (MMA), as monomeric units. We have evaluated the effect of different para-substitutes of 6-(4-azobenzene -4′-oxy)hexyl methacrylate, at the side chains, OCH 3 , NO 2 and H, on the phase behaviour and conductivity of the new polymers. The copolymers can form smectic and nematic phases, depending on their composition, and have light responsiveness, conferred by the azobenzene chromophores. The terpolymer with methoxy terminations, MeOAzB/AMPS/MMA, exhibits the highest conductivity values of the series (10−2/10−3 S·cm−1 range) through liquid crystalline phases and with signs of decoupling from polymeric segmental motions. These materials are promising candidates to develop new light-responsive polymeric electrolytes for electrochemical conversion devices in which ionic conductivity under anhydrous conditions can be controlled by their nanostructure. [ABSTRACT FROM AUTHOR]