Should a top-notch scientist, at age 51, decide to mentor a 47 years scientist, from a faraway country? Olivier Kahn did it, and I was the beneficiary — J.V. Yakhmi
Over a long academic career in scientific research, one needs mentors at different stages of one’s career. I, too, have had the benefit of several mentors, who helped me grow in my research career spanning 44 years (1966-2010) at Bhabha Atomic Research Centre, Mumbai. Some of them helped to steady my research career in the initial stages, some others offered valuable advice on how to handle the bottlenecks as I struggled to manage my small research group, while some of my mentors made sure that I got due credit for my achievements. All my mentors were nice human beings, senior to me, who never tried to gain anything from me in return, either by making me work for them or by seeking co-authorship in my publications. I did not consider my research collaborators in the category of my mentors, even if they were much senior to me in age, or experience.
Does someone, who has himself spent a long time in science, or any other profession, say thirty years, need a mentor, that too, when he is himself mentoring a few younger colleagues? Would it not be embarrassing? I would say not, if his own mentor is notches above him in a branch of scientific expertise. I wish to tell the story of one such mentor, the late Prof. Olivier Kahn (d. 1999), who very suddenly, and unexpectedly, offered to take me under his wings in 1993. I was 47 then, but a rank beginner in the subject of molecular magnetism, in which Kahn was considered topmost in the world, though he was just four years older than me. He chose to mentor me because, as became clear with time, he had identified a spark and hidden talent in me. Therefore, he undertook to pay special attention to make me scale the heights quickly in his favourite subject. And he did that in a hidden manner during the next six years, the remainder of his life, like no other mentor would do.
Before I met Kahn, I had done very well by international standards, in certain other areas of research, such as high-Tc superconductors, and magnetism of Cr-alloys. In recognition of these successes, I was awarded the ‘Rouge’ Fellowship of CNRS, in 1987 to work at Laboratoire de Physique des Solides at Universite Paris-Sud, Orsay (Paris) to work with Prof. I.A. Campbell, an acknowledged expert in the field of spin glasses, and subsequently invited as a Visiting Professor in the Physics Department of the University of Toronto in 1988 to work with Prof. E. Fawcett (d. 1998) on high-temperature superconductors and spin-density wave antiferromagnetism of Cr-alloys. Despite all that, I was eager to try my hands, during the period 1989-1992, on a challenging new area of research, preferably interdisciplinary, which had the intensity of physics and chemistry both, since as a physicist I had by then gained the advantage of having worked at Chemistry Division of Bhabha Atomic Research Centre for over two decades. During these times, I initiated some research activity in my group on synthesis and measurements on organic superconductors and Chevrel phase superconductors, and even toyed with the idea to work on fullerenes.
It was during this phase of scouting around that I took note of a path-breaking paper published by Prof. O. Kahn in Inorganic Chemistry journal in October 1991, which highlighted the synthesis of a molecular compound with the formula MnCu(pbaOH)(H20)2 which showed bulk magnetic order below 30 degrees Kelvin (Curie temperature). This gave me a thrill as big as I had got in 1986 when I saw the publication ‘Possible high Tc superconductivity in the Ba-La-Cu-O system’, by J.G. Bednorz and K.A. Mueller in Z. Physik B, for which they were awarded the Nobel prize in 1987. This was because Kahn’s group had opened the doors, for the first time, for employing just a simple closed cycle Helium refrigerator to cool the samples down to about 15K or so, and study the magnetic behaviour of the new high-Tc (Tc here stands for Curie temperature) molecular magnets. Before this publication, samples of all known molecular magnets had required the use of liquid Helium to cool them for studying them. Excitedly, I made a quick survey and updated myself with the work being done on molecular magnets until then, which was primarily limited to labs in Italy, Spain, Japan, USA and of course, in France by Prof. O. Kahn and his colleagues. I delivered a review talk on the subject of molecular magnets, too, in December 1992 to gain confidence.
But before taking a plunge into the new subject area of molecular magnetism, I wanted to fathom how hard it was to synthesize these organic compounds. Unfortunately, no group in India had yet taken up this effort. Hence, I decided to visit Kahn’s lab (at that time he was at Laboratoire de Chimie Inorganique, Université de Paris-Sud, at Orsay), and requested my former host at Orsay, Prof. Ian Campbell, to help me do so. He agreed and I made a stop-over at Paris, while returning to Mumbai from Toronto in February of 1992.
On Feb 14, 1992, Prof. Campbell took me along to see Kahn’s lab, and to speak to him. To my dismay, Kahn spent just a few minutes with us, after which he asked a Japanese guest scientist to show us his labs. This short tour of Kahn’s lab convinced me that it would be possible for my research group to conduct the chemical synthesis of molecular magnets at Mumbai. But I was sad that I couldn’t do any detailed subject-related discussions with the master, Olivier Kahn himself. I later learnt that Kahn was working very hard that day to give finishing touches to the manuscript of his celebrated book “Molecular Magnetism” which he was to submit to Wiley-VCH Publishers, the next day. This book was published in 1993. Later events showed that I was destined not only to meet him often but also to collaborate with him intensively.
The chance for me to meet and discuss with Kahn came soon, in 1993, when he visited India, representing the science minister of France, and went around some premier research institutes in India to propose new bilateral scientific collaborations between Indian and French labs on Rare Earth-based materials (India has large RE mineral stocks). During this trip, he also visited my institution BARC, at Mumbai, and delivered a talk on molecular magnets, during which he also referred to his paper published in Science journal earlier that year. Since I had been tracking his work, and had also read his paper mentioned above, I could ask him pointed questions on molecular magnetism. He was delighted and invited me for a one-to-one discussion after his talk, during which I showed him the OHPs of my own lecture on the topic (hesitantly though, because I was yet to start working on this subject, and he was the top global expert on it). Delivered by me a few months earlier, my talk was essentially an update on the progress of the subject of molecular magnetism, covering not only the essence of Kahn’s own work, but also the work done by the group of Prof. Dante Gatteschi in Italy, Prof. J.S. Miller’s group in USA, and by Prof. Hiiju Iwamura’s group in Japan.
Kahn went back to France and made a Report on his Indian visit to the French Government and to IFCPAR (Indo-French Centre for the Promotion of Advanced Research, called CEFIPRA in French) suggesting which French and Indian research groups should propose joint collaborative projects. At the end of his report, he wrote that he would like to propose a CEFIPRA project with me, and Prof. S. Ramasesha, from Indian Institute of Science, Bangalore as Principal Indian Investigators. Subsequently, he wrote this project proposal himself and submitted to CEFIPRA, which approved it as a three-year project in mid-1994, to begin formally in April 1996. I was thrilled, because I was getting a golden opportunity for a collaboration on molecular magnets with Prof. Kahn, who was not only a pioneer in it, but also a Member of College de France, an honour given to only about a dozen French chemists of the time. Therefore, I started earnest efforts to initiate work on molecular magnets in my labs. Based on some new samples made by us at BARC, I proposed the first-ever Muon Spin Rotation (MUSR) experiment on transition-metal based molecular magnets, which was approved by Rutherford Appleton Lab (R.A.L., Oxford), and conducted by me at R.A.L. in September 1995.
Kahn had by then shifted to the University of Bordeaux, at Pessac, in south-west of France, with special funding to set up his new lab at ICMCB (Institut de Chimie de la Matière Condensée de Bordeaux).
Kahn invited me to participate in the NATO Advanced Research Workshop on Magnetism: A Supramolecular Function, an International Conference that he organized in Carcans-Maubuisson, about 70 km north-West of Bordeaux, at a lakeside hotel (lac d’hourtin) during September 16-20, 1995. I clarified to Kahn that my country India was not a member of NATO. He said, ‘No Problem’. So, I participated, and found that nearly everyone working on molecular magnetism, anywhere in the world, was attending. There was a lot to learn at this conference because there were no parallel sessions. I had only a poster to present, which I did on the first day of the conference.
Kahn had a surprise for me on the second day of this NATO conference, when he asked me to chair a three hours long session. I tried to wriggle out stating how could I, a beginner, chair a session in which world-rankers were to be introduced before their talks? His quick reaction was almost a threat: ‘Will you chair or not’? I did. A few years later, I learnt that Kahn had done this intentionally to boost my stock and visibility among the subject experts. At the Conference Banquet, Kahn asked me to sit on a table where all others sitting were Japanese scientists. At that time, Japan had a large number of research groups working on molecular magnetism, second in number only to France, and Kahn wanted to give me the opportunity to interact with them. Prof. Takeji Takui from Osaka City University confided in me several years later that Kahn had recommended my name highly to many Japanese scientists working on molecular magnets, and asked them to take care of me whenever I visited Japan.
I was invited by Prof. Hiizu Iwamura to come over to Japan to participate in a Gordon Research Conference (GRC), on the theme of “Organic Structures and Properties” organized by him in Fukuoka (Japan) in September 1996. Before that, my joint CEFIPRA project with Kahn had taken off in April 1996, and a PhD student from my group in Mumbai had been sent in June 1996 to work for six months in Kahn’s lab at Bordeaux to attempt the synthesis and study some new compounds under his guidance.
The GRC that I mentioned above was a prestigious one, being the first-ever Gordon Conference on any topic to be organized in Asia, and as the Chairman of this conference, Prof. Hiizu Iwamura, a renowned Professor of Chemistry in Japan, who is now 86, had not only sent me a personal invitation to attend, but had also obtained the approval of funds from JSPS (Japan Society for Promotion of Science) to me to attend it. I was taken aback since I had not sent any Abstract for participation. Besides, I was a physicist with some experience of working on problems related to physical chemistry or solid-state chemistry, but was quite raw myself in organic chemistry, the theme of this GRC. I did not notice the hidden hand of Kahn behind this. There were about one hundred participants, most of them being stalwarts in molecular organic chemistry, and I was among the only two or three physicists attending. Luckily, I had kept myself updated about the recent strides made by experts like Prof. Iwamura himself on the design of organic magnets. The inaugural speaker was Prof. James Stoddart, who won the Chemistry Nobel Prize later in 2016. I made just a poster presentation. But during this maiden trip to Japan, I was already feeling important, rather being made to feel so, having got a chance to visit several important labs in Japan, viz. N.E.C. Corporation in Tsukuba, Electrotechnical labs in Tsukuba, ISTEC in Tokyo, Kyoto Institute of Technology in Kyoto, Kyushu University at Fukuoka, Osaka City University at Osaka, Toyohashi University of Technology at Toyohashi, and University of Tokyo. The hidden hand of Kahn, my academic mentor, was now getting clear to me, because wherever I went, the hosts would ask me if I knew Kahn well, or about my collaborations with him. I will inform them, with a sense of pride, about our joint CEFIPRA project which was already yielding results.
The author (R) With Prof. Olivier Kahn at the latter’s lab at ICMCB, Bordeaux, in March 1999.
Under our joint project, I spent one month each on two occasions as a guest scientist in Kahn’s lab, first in May 1997 and then in March 1999. It was exciting to watch how he inspired his group members, and collaborators, with his ingenuity and depth of understanding about the characteristics of several series of new molecular magnets designed by him and prepared in his lab. Often times, he came up with entirely new insights into the observed scientific data, giving a totally different, and a higher meaning to the results obtained. Such was his hold on the scientific concepts, and grasp on the subject that he could think like none else could. I would sit before him in quiet admiration. For instance, for the first time, he came up with the concept of Molecular Magnetic Sponges on our samples, which by losing some amount of water, or gaining it per molecule, could go into reversible changes in their magnetic behaviour, an idea much copied later by several groups on other new materials.
Starting in late 1970s, very many colleagues and students who worked with Kahn during his illustrious career, went on to become group leaders and Professors, in different labs in Europe, and continued to work in the directions given by him. Some of them are active even now. He was a mentor to several people at any given time, and took care of shaping dozens of careers. Having interacted with and collaborated with him during perhaps his most productive period, I had a chance to interact with the members of his group at Bordeaux and observe the work culture in his lab closely. I also got to interact with or even visit the labs of several of his collaborators in Europe or Japan. I must agree that I was largely welcome because I was a collaborator of Kahn, basking in his reflected glory, so to say. A common question that my hosts would ask me was, ‘how did I come close to Kahn’.
New ideas and concepts would come to him quick and fast. During our CEFIPRA sponsored 3-year collaboration, we could publish about 30 joint papers. CEFIPRA also honoured us with the Award of ‘Excellence’ for conducting our Indo-French Project No. 1308-4 so well, during 1996-99.
Kahn would normally work upto 7.30 pm or so in his lab, analysing data obtained by his students, and preparing manuscripts. The pace of his publications in journals was brisk. On two or three occasions, he told me to sit in my room and wait for the draft of a new manuscript, which he would be finalizing in the next one hour or so. He would then bring me that manuscript, and state ‘now you can look at it and make your corrections’. Considering his lofty status in the field of molecular magnetism, I would feel embarrassed to do that, but just to satisfy him I would read word for word, and make one or two minor grammatical corrections in English. Satisfied, he would close shop for the day, and drive me to my guest house, before returning to his residence, which was far out in the countryside.
I had ample chance to observe Kahn as a human being, too. He often took me along for official lunches organized by him for visiting dignitaries. I guess, this too was his way of grooming me. Being a Bordeaux man, Kahn had a great sense of the quality and source of wines, and he would often coach me about the culture of wines. I would go for red wine and generally preferred fish at formal lunches. Once, he invited me for a special lunch with a French Government official from Paris. The main dish ordered was duck. Kahn, knowing that I was more of a vegetarian than not, was observing my struggle with chewing pieces of duck. I thought I managed to ‘duck’ one or two partly-chewed pieces of the duck by hiding them behind a bowl, when Kahn was engaged in talking to the guest. After a week, Kahn and I went to another restaurant for lunch, and while in the middle of it, Kahn told me that he could see that I had not liked the duck during the special lunch!
Prof. Olivier Kahn (R) with the author at latter’s residence in Mumbai in February 1997
He used to come to receive me at Bordeaux airport, when I arrived from India. I used to often show off to him that I travel light with just one small wheeled unit and a soft zipped bag, even on my international trips. Once after my arrival at Bordeaux airport, we were loading my luggage in the boot of his car, and Kahn suddenly told me, “You have a big bag this time, against your preference to travel light!”
Kahn also allowed me my share of fun at his expense. While making a presentation on the progress of our joint project, before him and his group in his lab in January 1999, I claimed that we at Mumbai were working on at least fifteen jobs, listing them sequentially, as against just about six jobs being done at Bordeaux, by cleverly amplifying the Mumbai lab contributions. Knowing my game, he merely smiled, and never challenged me, because both of us knew that the truth was just the reverse.
He cared for me endlessly. I once wanted to visit the lab of Prof. J.-P. Tuchagues at Toulouse, but was not getting any response to my email. Knowing this, Kahn spoke on phone to Tuchagues, and scheduled my visit. Kahn also asked his secretary to get me train tickets at my desk, so that I didn’t have to go to Gare de Bordeaux-Saint-Jean to buy them. He even came to leave me at Bordeaux station.
After the completion of the Nato conference organized by Kahn at Carcans in September 1995, he drove me and Prof. Peter Day (from UK) back to Bordeaux, and after an hour in his lab he dropped me at the railway station at Bordeaux where I had to catch an overnight train to Lyon to visit a lab in Grenoble. He bid goodbye to me and also mentioned that he has to leave for Paris next morning, and he is rushing home to catch up with some sleep, after the hectic conference that had exhausted him. Imagine my chagrin when I entered the Bordeaux station only to find that there was a sudden strike and closure of trains by SNCF. I called Kahn from a public telephone to tell this. He told me to call him again after 10 minutes, during which he fixed for me a night’s stay at a Hotel right across Bordeaux station, and told me about it when I called again. Besides, he instructed that his wife Joanna, whom I knew, would meet me next morning at 10 am at my hotel and would first go with me to the station to claim refund for the cancelled train trip and then buy me an air-ticket from Bordeaux to Lyon, and drive me to the airport, all of which she did!
During the second-half of 1999, I was on long medical leave due to a heart attack that I suffered in July 1999, and had to undergo a bypass-surgery (CABG) in September. I was allowed to join back duties at my job only in December, after due recuperation. I felt Kahn would be upset to know about this, so I never disclosed it to him in my emails. During October that year, I got a call from CEFIPRA to make a presentation on the completion of our project before a meeting of the CEFIPRA Committee to be held in middle of December 1999, at Bhopal. I wrote to Kahn about it stating that I couldn’t make a presentation, as I had fractured my leg and have a plaster (a lie, instead of telling him that I was recuperating from my heart surgery). He said, no problem, he will travel to India to make a presentation. That was not to be. He passed away suddenly on Dec. 8, 1999, while delivering a lecture at College de France, in Paris.
I went to Kahn’s lab in March 2000, on a bonus visit awarded by CEFIPRA since our joint project was adjudged “Excellent”. Everything was at its place, except the presence of Kahn. I looked for the piano that he had installed in the corridor of his lab in 1995. It was there!
During the few months subsequent to the passing away of Kahn I was quiet and felt rudderless and distraught. I met several of our common friends across the world at the VIIth International Conference on Molecular-based Magnets (ICMM 2000), held at San Antonio, TX, during 16-21 September 2000, where I, being his last major collaborator, was invited to chair a session.
Times spent with Kahn made me appreciate the methodology of working of a great scientist like him, and learn how to create opportunities for one’s younger colleagues, without much fanfare.
Author: Prof. Dr. J.V. Yakhmi, E-mail: email@example.com