WORM type memory device based on ionic organotin complex using 1,5-diphenyl-3-(2-pyridyl)formazan ligand

Synthesis, structure, and write once read many (WORM) type memory behavior of an ionic organotin complex containing a 2-pyridine substituted formazan ligand is described herein. Ionic organotin complex (1) was obtained by the reaction of diphenyltin dichloride with 1,5-Diphenyl-3-(2-pyridyl)formazan ligand (L) in the presence of dilute hydrochloric acid in a 2:1 molar ratio in refluxing toluene for 24 hrs. The structure of complex 1 was confirmed using the single-crystal X-ray diffraction technique, which reveals an octahedral tetrachloridodiphenylstannate and a trigonal bipyramidal dichloridotriphenylstannate anions interacting with 1,5-Diphenyl-3-(2-pyridyl)formazan cation by the attractive force as well as hydrogen bonds between them. When applied as an active material in a metal insulator metal (MIM) type memory device, complex 1 exhibited unique write once-read many (WORM) type switching memory characteristics with a high switching on-off ratio of 104. The device interestingly also shows low switching voltage and good reading capability. This work offers a new direction for the rational design and fabrication of high-performance write-once-read-many (WORM) type memory devices based on ionic organotin complexes.