'It was from him I learnt that if you gave the student the freedom to find his own path, he would be more courageous to experiment.'
IMAGE: Professor Omar Yaghi in his lab at the University of California, Berkeley, in an undated photograph.
Professor Yaghi won the 2025 Nobel Prize in Chemistry, alongside Richard Robson of the University of Melbourne and Susumu Kitagawa of Kyoto University on October 8, 2025. Photograph: Brittany Hosea-Small/UC Berkeley/Handout/Reuters
There is a lot of excitement among the Indian scientific community after the Nobel Prize for Chemistry was announced.
Two scientists from India did their post doctoral work under two of the Nobel Laureates; Professor Rahul Banerjee did his post doc under Professor Omar Yaghi and Professor Tamas Kumar Panda under Professor Susumu Katigawa.
Incidentally, Professor Tamas Panda did his PhD under Professor Rahul Banerjee.
IMAGE: Professor Susumu Kitagawa addresses a press conference in Kyoto, Japan, October 8, 2025, after winning the 2025 Nobel Prize for Chemistry. Photograph: Kyodo/via Reuters
Professor Rahul Banerjee is now a Professor in the Department of Chemical Sciences Indian Institute of Science Education and Research (IISER) in Kolkata.
In this interview with Shobha Warrier/Rediff, he remembers his mentor, Professor Omar Yaghi under whom he did his post doc at the University of California, Los Angeles (UCLA) 20 years ago.
"It was in his lab that I learnt what we as scientists needed the most, intense work. There are no short cuts in research, you have to work really, really hard till you get the results," recalls Professor Rahul Banerjee.
IMAGE: Professor Rahul Banerjee with Professor Omar Yaghi in Sweden. Photograph: Kind courtesy Professor Rahul Banerjee
Wanting to do a post doc on metal-organic frameworks (MOFs)
While I was doing my PhD on structural chemistry under Professor Gautam R Desiraju at Hyderabad University, I started thinking what I should do for my post doc.
It was by accident that I happened to read a scientific paper by Professor Omar Yaghi on something called metal-organic frameworks (MOFs).
Remember it was in 2005, 20 years ago and I had no knowledge of what metal organic frameworks were!
What attracted me about the article was the beautiful pictures of MOFs in bright colours!
Though I had no idea what the subject the professor was talking about, I wanted to work on MOFs, simply because I was attracted by the images he had created.
Unlike the students of today who plan everything about their lives, I was totally clueless about the subject I wanted to study for my post doc!
But I was sure about one thing: I wanted to do my post doc under the gentleman who wrote the article and drew those pictures.
And he was Professor Omar Yaghi.
Photograph: Kind courtesy kitagawagroup/@NobelPrize/X
I found that he was a professor at the University of Michigan.
When I told my PhD mentor Professor Desiraju that I wanted to do my post doc under Professor Omar Yaghi, the first question he asked me was, will you be able to handle him?
I asked him, why? He said, Professor Yaghi is an absolute livewire!
I had no idea what to expect but I was still sure about one thing, I wanted to do my post doc under him.
Then, my supervisor said, If you really want it, apply to him. But also apply to some other universities too, in case, he said no to you.
So, I applied to him and some others also.
IMAGE: A screen displays the 2025 Nobel Laureates in Chemistry: Susumu Kitagawa, Richard Robson and Omar M Yaghi as they are announced at a press conference at the Royal Swedish Academy of Sciences in Stockholm, Sweden, October 8, 2025. Photograph: TT News Agency/Fredrik Sandberg/Reuters
Writing to Professor Yaghi
I wrote a simple mail to Professor Yaghi saying I was a PhD student at Hyderabad University who was about to submit my thesis to Professor Desiraju.
I also admitted in the mail that I was fascinated by the images he had drawn in his scientific paper.
I then asked him whether I would be able to do my post doc under him.
I was taken aback to get a reply from him within 12 hours.
I didn't open the mail for some time as I was sure that it was a rejection saying he had no money to have any more post doc students.
But I was in for a huge surprise! In the mail he said, he had a place open and he would like me to have it. But he wanted my professor to write a recommendation letter.
I just couldn't believe my eyes!
That was the first application I had sent and I got a positive reply, that too from the professor I wanted.
This was when my friends were complaining about not getting any reply from the professors they had applied to.
I immediately showed the mail to my supervisor. He said, he would be meeting Professor Yaghi at the Pacifichem conference in Hawaii in a few days, and he would talk to him directly.
A week after Professor Desiraju spoke to him, I got an offer letter from Professor Yaghi as his post doc student. Without any interview.
Professor Yaghi wrote to me that he was no longer at the University of Michigan and was about to join the University of California, Los Angeles (UCLA).
IMAGE: Professor Omar Yaghi in his lab at the University of California. Photograph: Brittany Hosea-Small/UC Berkeley/Handout/Reuters
Joining Professor Yaghi's group at UCLA 19 years ago
I joined Professor Omar Yaghi on the 4th of August 2006 as his post doc student 19 years ago.
It was my trip to anywhere outside India. I didn't know what to expect.
Everybody told me it was going to be very expensive living in Los Angeles. So, the constant worry I had was, where would I find an affordable place to stay.
It was indeed a nightmare to find an accommodation next to the university.
Initially, I stayed in a small hotel close to the university and I had to shell out $60 a day! That was almost 20 years ago!
Finally, I found a studio apartment in Santa Monica, and I had to travel an hour to reach the university.
I went to the university on the first day itself, but Professor Yaghi was not there, he was attending some conference.
I saw there were around 30 people in his group, and everybody appeared super busy with their work. Somebody showed me where my seat was.
IMAGE: 'Feeling very lucky to work with Prof Kitagawa as a JSPS Postdoctoral fellow. Wonderful memory in my canvas. Kitagawa research group is a brand and happy to be part of this group' Tamas Panda posted on X. Photograph: Kind courtesy @tamaschem/X
Meeting Professor Omar Yaghi
I started coming to the lab from the next day but had not yet met Professor Yaghi. He was still at the conference.
Professor Yaghi was 40 years old then, already a professor and an extremely successful and renowned scientist in the field of chemistry because of the work he was doing on MOFs.
I was told by one of the group members that if I wanted a bottle of cold water, I could get from Professor Yaghi's room. So, one day when I went to collect water, one gentleman opened the door.
And it was Professor Omar Yaghi, a young man with very sharp features and full of energy.
When I introduced myself, he said, hello, come in. I will give you some projects to do.
While he gave me instructions on what to do, nothing registered in my mind as I was still worrying about finding an affordable place to stay.
Only after seeing him, did I realise what Professor Desiraju meant by 'live wire'.
Professor Omar Yaghi was indeed a live wire!
IMAGE: Omar Yaghi created a very stable MOF and showed that it can be modified using rational design, giving it new and desirable properties. Photograph: Kind courtesy @NobelPrize/X
Starting to work in the Yaghi group on metal-organic frameworks (MOFs)
Once I started as the post doc, I realised that behind the beautiful pictures which made me join him, there was a lot of hard work.
One thing Professor Yaghi used to say was, our research should be unique, and people should feel after reading our papers, wish we had thought about this!
But that was the time nobody believed in what he was talking about, creating a new material called metal-organic framework.
He used to tell us; this is the idea. It is your job to make sure that it works.
It was in his lab that I learnt what we as scientists needed the most, intense work. There are no short cuts in research, you have to work really, really hard till you get the results.
When you are doing research, both your body and mind would be working. Your strategies will fail. Then, you have to find new ways. That also may fail. You may fail many times.
By the time you reach home every day, you will be drained both physically and mentally.
But you have to energise yourself to work again and again... till you succeed. It is a very hard and long journey to success.
Most of us used to start work in the lab at 7 in the morning and worked till 9 at night. Professor Yaghi also was at the work by 7.30.
Monday to Sunday, we worked like that, every single day. Sometimes, we even stayed in the lab itself.
IMAGE: Professor Omar Yaghi works with students in his lab at the University of California in an undated photograph. Photograph: Brittany Hosea-Small/UC Berkeley/Handout/Reuters
Style of working: Find your own path
When you are stuck in your research, who will show you the path?
Professor Yaghi's policy was, we have to find the path ourselves through trial and error, through intense work.
Whenever I went to him with a result, he would ask, what is it good for?
I would say I have no idea.
He would then say, find out what you will do with it. It is for you to find it out.
It was from him I learnt that if you gave the student the freedom to find his own path, he would be more courageous to experiment. As the mentor, you need only to see that he doesn't lose the direction.
This is what I tell my research students too.
The work I did was on Zeolitic imidazolate frameworks (ZIFs) (a subclass of metal-organic frameworks (MOFs) that are formed by the self-assembly of transition metal ions).
Finally after one year, he was satisfied with my result. He told me the project was over, and that I should stay in the next seven days in the lab and write the draft.
Then I published the paper in a science magazine.
My research with him continued for another two years.
'Addictive chicken' at Professor Yaghi's home
Professor Yaghi was very happy when my paper got published.
To celebrate it, he invited the authors of the paper to his home for dinner.
After every such publication, he would invite the authors to his place for dinner.
What is special about the dinner was an exclusive dish he prepared for us,. And he called it 'addictive chicken'.
It was over dinner that he would talk to us about the difficult childhood he had, growing up in a very poor, large family.
He also would talk about the need to work on MOFs as he believed the future lay in those materials.
You have to remember that 20 years ago, nobody believed that MOFs would be a big thing. Majority of the people criticised the new metals we spoke about. They called it absolute garbage!
The critics said when you have so many other materials, what use does this have?
But Professor Yaghi believed in what he was doing. He believed it would work and it would be accepted one day.
IMAGE: Professor Rahul Banerjee delivers a talk at the S N Bose Centre for Basic Sciences. Photograph: Kind courtesy @AbulHas60118814/X
As the only Indian scientist at the Nobel Symposium
Every two years, the Nobel committee organises a symposium on a subject that has a chance to win a Nobel Prize, and they invite scientists from all over the world.
In 2023, I was invited to join the symposium in Karlskoga in Sweden as the only scientist from India.
Professor Omar Yaghi was also there to talk about MOFs.
After the conference, when we were chatting I said, 'Sir, I was the first Indian student who did his PhD in India, to work under you.'
His reply was, 'the first and the best!' Probably, he was being polite. Anyway, he made me happy!
He is still a live wire with the same energy and passion for science. Maybe age has physically slowed him down a bit. He is 60 now. But mentally, he is the same energetic live wire!
IMAGE: A selfie with Professor Omar Yaghi in Sweden. Photograph: Kind courtesy Professor Rahul Banerjee
Nobel Prize in 2025
When the Nobel Prize was announced, I was not surprised at all.
I was certain that he was going to win the Nobel Prize. The question was whether it would be today, tomorrow or day after.
I would say MOFs are the hottest subject in chemistry now, and these are the most exciting times for all of us.
I wrote him a congratulatory mail with a footnote, 'I know you would be very busy. So, please don't bother to reply'.
But he did.
He wrote,
Dear Rahul,
Thank you so much for your incredibly kind and generous words. Your heartfelt congratulations mean a great deal to me.
It is deeply gratifying to know that my work has inspired dedicated scientists like you.
I truly believe that passion, perseverance, and dedication are the keys to making meaningful contributions in science, and it is encouraging to hear that this message resonates with you.
I am honored to have played a small part in inspiring the next generation, and I look forward to seeing the amazing discoveries from you.
With my deepest gratitude and warmest regards,
Omar
Photographs curated by Manisha Kotian/ Rediff.com
Feature Presentation: Ashish Narsale/Rediff.com