If we utilize the example of an ascending staircase, then the first action, i.e. the very first thrilled state of the molecule, is high, and each subsequent action is lower and for that reason closer to the previous one. On the other hand, an antiaromatic compound is unsteady, and the molecule attempts to get away from this state as rapidly as possible. With their research study, Slaninas team is reacting to the requirements of the present, which looks for a way to ensure that the energy from photons (e.g. from the Sun) recorded by a particle is not lost and that it can be further used (e.g. to transfer energy in between particles or for charge separation in solar cells). Furthermore, in the current paper, the researchers reveal in many cases that the property of azulene is transferable; it can be simply attached to the structure of any aromatic particle, thanks to which that molecule gets the key properties of azulene.
In their research study, the scientists at IOCB Prague utilized several unique programs that can determine how electrons in a molecule behave in the abovementioned higher ecstatic states.
Researchers have actually deciphered azulenes special habits, paving the way for advances in organic chemistry and effective light energy capture. Above is an artistic making of the uncommon habits of azulene. Credit: Tomáš Belloň/ IOCB Prague.
Scientists from IOCB Prague are the first to describe the causes of the habits of one of the essential aromatic molecules, azulene. This particle has captivated the clinical community not simply with its distinct blue hue, but also with its special homes.
Their present endeavor will influence the structures of natural chemistry in the years to come and in practice will help harness the maximum potential of captured light energy. Their findings were just recently released in the Journal of the American Chemical Society ( JACS).
Azulene has piqued the curiosity of chemists for several years. The question of why it is blue, despite there being no obvious reason for this, was answered practically fifty years ago by a researcher of worldwide importance, who, coincidentally, had close ties with IOCB Prague, Prof. Josef Michl.
Now, Dr. Tomáš Slanina is following in his footsteps in order to use his coworkers in the field the solution to another puzzle. He and his associates have actually convincingly described why the tiny azulene particle violates the universal Kashas guideline.
This guideline discusses how particles produce light upon transitioning to various excited states. If we use the analogy of an ascending staircase, then the initial step, i.e. the very first ecstatic state of the molecule, is high, and each subsequent action is lower and for that reason closer to the previous one. The smaller sized the range between the steps, the faster the particle tends to fall from the step to lower levels. It then waits the longest on the primary step before returning to the base level, whereupon it can release light. Azulene behaves differently.
To describe the habits of azulene, scientists at IOCB Prague used the principle of (anti) aromaticity. Once again, put simply, a fragrant substance is not identified by a fragrant odor but by being stable, or satisfied, if you will. Some chemists even describe it informally with the familiar smiley face emoticon.
Dr. Tomáš Slanina, head of the Redox Photochemistry group at IOCB Prague. Credit: Tomáš Belloň/ IOCB Prague.
On the other hand, an antiaromatic compound is unstable, and the particle tries to leave from this state as quickly as possible. It leaves the higher energy state and falls downward. In the very first step, azulene is unhappy, i.e. antiaromatic, and therefore falls downward in the order of picoseconds without having time to discharge light.
It can exist in this ecstatic state for even a full nanosecond, and that is long enough to release light. The energy of this excited state is not lost anywhere and is totally converted into a high-energy photon.
With their research, Slaninas team is responding to the needs of the present, which seeks a method to make sure that the energy from photons (e.g. from the Sun) caught by a molecule is not lost which it can be even more used (e.g. to transfer energy between molecules or for charge separation in solar batteries). The objective is to produce particles that handle light energy as effectively as possible. Furthermore, in the present paper, the scientists show in lots of cases that the property of azulene is transferable; it can be simply connected to the structure of any aromatic particle, thanks to which that molecule gets the key residential or commercial properties of azulene.
Tomáš Slanina includes: ” I like theories that are so simple you can quickly visualize, remember, and then put them to use. And thats precisely what weve prospered in doing. Weve responded to the question of why particles behave in a specific way, and weve done it using an extremely simple concept.”.
In their research study, the scientists at IOCB Prague utilized a number of distinct programs that can determine how electrons in a particle behave in the abovementioned higher excited states. Little is understood about these states in general, so the work is also groundbreaking since it unlocks to more research study. Moreover, the post published in JACS is not just computational but also speculative.
Scientists from Tomáš Slaninas group supported their findings with an experiment that precisely validated the correctness of the determined information. They likewise worked together with one of the worlds most respected authorities in the field of (anti) aromatic molecules, Prof. Henrik Ottosson of Uppsala University in Sweden. And this is the second time JACS has taken an interest in their collaboration; the first time remained in relation to research on another primary particle– benzene.
The story of azulene is even more layered. Like the first area, the second also bears the seal of IOCB Prague– one of the first drugs developed in its laboratories was an ointment based on chamomile oil containing a derivative of azulene.
Recommendation: “Excited-State (Anti) Aromaticity Explains Why Azulene Disobeys Kashas Rule” by David Dunlop, Lucie Ludvíková, Ambar Banerjee, Henrik Ottosson and Tomáš Slanina, 13 September 2023, Journal of the American Chemical Society.DOI: 10.1021/ jacs.3 c07625.
By Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague).
September 21, 2023.
