Advancement in Molecular Memory Technology: A New Frontier in Data Storage

A method to control switching between different forms of Fulgimide photoswitches has been developed, as explored in a study by Lucie Wohlrábová at IOCB Prague. The research reveals the potential for these photoswitches to exist in three distinct forms.

Photoswitches, molecules which can alter their structure in response to light pulses, are typically restricted to two states. However, researchers at the Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) have now created a molecule capable of switching between three states. This novel molecule offers the capability to hold a larger amount of complex information within its structure.

Although it was theorized that similar molecules could attain a third state, scientists have been reluctant to study this process due to difficulty controlling transitions between molecular forms. Now, a study led by Dr. Tomáš Slanina—and co-authored by PhD student Jakub Copko—has bypassed these issues, the findings of which have been published in Chemical Communications.

"The ability to accurately control switching molecules between three distinct states allows for a more diverse range of molecular interactions," explains Jakub Copko.

Light-induced changes in photoswitches are typically seen in alterations in macroscopic properties such as color changes. The changes are easily perceivable to the naked eye, allowing individual molecules to serve as memory bits. However, these molecules can store far more information than silicon-based chips due to their smaller size. These transitions, according to Dr. Tomáš Slanina, are only possible with photoswitches that do not switch between states spontaneously, a requirement previously difficult to fulfill.

The geometry of a molecule significantly changes when transitioning from the second state to the third, something that can be useful for manipulating molecules to fit or not fit into target active centers. Activated by specific light pulse wavelengths, this discovery has made it possible to apply this mechanism in numerous practical applications.

Dr. Tomáš Slanina and his team have been studying photoswitches specifically focusing on fulgids, which only a few laboratories worldwide investigate even though these substances generally possess superior properties than other photoswitches. The challenge lies in their complicated preparation process.

Jakub Copko found a way to mitigate this problem using a "one-pot reaction" method: all chemical transformations are executed in a single flask, getting rid of the need for isolating and purifying all intermediate substances. In addition to streamlining the procedure and creating a cleaner reaction with greater output, this method lessens environmental impact.

"We aim to raise wider awareness about fulgides, which can considerably advance the field of photoswitches on a global scale," Slanina remarks.

As per this team's endeavours, preparation is now so efficient that any synthetic chemistry lab, even those without prior experience with photoswitch chemistry, can produce these photoswitches.

Reference: “Multiplicity-driven photochromism controls three-state fulgimide photoswitches” by Jakub Copko and Tomáš Slanina, 13 February 2024, Chemical Communications. DOI: 10.1039/D3CC05975H