A solution-processable benzothiazole-substituted formazanate zinc(II) complex designed for a robust resistive memory device

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 53; no. 36; pp. 15338 - 15349
• Main Authors: Birara, Sunita, Saini, Shalu, Majumder, Moumita, Tiwari, Shree Prakash, Metre, Ramesh K
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 18.09.2024
• Subjects: Chemical reduction; Coordination compounds; Crystallography; Data storage; Equivalence; Ligands; Memory devices; Oxidation; Valence; Zinc; Zinc compounds
• ISSN: 1477-9226; 1477-9234; 1477-9234
• DOI: 10.1039/d4dt01640h

A novel mononuclear bis(formazanate)zinc complex (1) based on a redox-active 1-(benzothiazol-2-yl)-5-(2-benzoyl-4-chlorophenyl)-3-phenyl formazan ligand has been synthesized and characterized. Complex 1 was prepared by reacting one equivalent of Zn(OCOCH )·2H O with two equivalents of the corresponding formazan derivative. X-ray crystallography was employed to ascertain the solid-state structure of compound 1, and the analysis revealed a distorted octahedral geometry for the complex where the symmetrical ligands exhibit a preference for coordinating with the zinc center in the 'open' form, generating five-membered chelate rings. Moreover, cyclic voltammetry analysis reveals that complex 1 exhibits the capacity for electrochemical reduction as well as oxidation, resulting in the formation of radical anionic (L Zn ) and dianionic (L Zn ) states as well as the oxidation state of 1. Additionally, the developed solution-processable complex 1 was employed as the fundamental building material for resistive switching memory applications. The [FTO/Zn L (1)]/Ag RRAM device demonstrates exceptional resistive memory switching properties, with a substantial / ratio (10 ), low operational and (0.9 V and -0.75 V) voltages, excellent endurance stability (100 cycles), and decent retention time (more than 2000 seconds). The findings presented in this study underscore the importance of redox-active formazanate metal complexes for creating promising memory storage devices.