Tuesday, June 23, 2020

Escape from SARS CoV-1 (Part-A)

          An evening around 7 pm in 2003. I was drying an NMR tube to record the NMR of my reaction product. Someone of our colleague told me that a virus called SARS (Severe Acute Respiratory Syndrome) was emerging in Mainland China and killing many people. We were at National Taiwan Normal University, Taipei, Taiwan. SARS was first identified in Guandong province in China which was believed to be transmitted from bat to cat and then to humans. Many people are dying in China and were transmitted to Hong Kong and Singapore too. It was the month of March when I first heard that. I did not realize it will come to Taipei too. Slowly at the end of April people in Taipei also affected and started dying. The doors of the University canteen was closed except one. We had to stand in a queue to get in and police were checking the temperature of the students. There was no infrared equipment for checking temperature and it was checked by a small machine putting the sensor inside our ear hole. If anybody found more than 38 degrees Celcius he/she would be quarantined. A panic situation and I felt sick for nothing. I used to have some paracetamol and took pills twice a day without any fever. I was thinking that if they will get my temperature more than 37 then I would probably be quarantined. It gave me mental agony as I was living in Taipei alone. Day by day situation was getting worse. Every day we had news of death around 50 to 100 people from SARS in Taipei hospital. Travelling was restricted but no lockdown was administered. Including me, there were three Assamese living in Taipei so I knew. One afternoon the Professor of Guwahati University who was doing his post-doctoral research at National Taiwan University told me that he is leaving for Assam the next day. I was thinking the whole night and finally decided to come back with him together. The next morning I called him and went to buy the ticket in the same flight. The flight was almost empty and I bought the ticket. Flight time was at 7.30 pm. I informed my mentor and handed over everything during the day. I did not forget to carry a packet of hand gloves and some of the pure alcohol from the lab. We both covered our face with cloths, hands with gloves, and arrived at the Taipei International airport on time. Airport was almost empty and only the staff members are working. Not many passengers. After screening our body for temperatures we boarded on the flight. There were hardly 30 passengers inside the flight.  Every time we went to the toilet we changed our gloves. It was a non-stop flight of China Airlines to New Delhi.
 
 
Taiwanese Colleagues with the Japanese Prof. Dr. Akira Suzuki, after his lecture at the NTNU, 2003.
Prof. Suzuki received the Nobel Prize in Chemistry in 2010 for his famous Suzuki Coupling Reaction.
                                                  
      Indian colleagues at the NTNU lab

Sunday, June 21, 2020

Slipping on ice

            December month. An afternoon, just after the white Christmas in Aarhus. I, with some other friends, was roaming around on the street. It was white everywhere with snow. We had holidays till the 3rd of January and were free. All the water bodies around us except the water of Kattegat sea were solid. I didn't realize what happened to me suddenly and I ran alone to the solid water beside the street from our group. It was solid water and we can walk but I didn't know the slippery surface. I slipped and fall down on the surface of the solid ice and could not stand, I was already a bit far from the street due to sliding. From there I crawled back to the street. All my friends were laughing at my situation of how I was coming back. Oops, a horrible experience as I was really frightened in the middle of the ice surface.

The Science behind: The surface of ice always have a thin layer
 of water. It is known fact that water on a smooth surface is slippery due to low viscosity of the water. It is similar like when water spilled on the tiles floor makes the tiles slippery. I did not know that before. Luckily nothing happened to me that day but it could be really dangerous.
We need to be careful....

                                                   











                                                                                                    

Friday, June 19, 2020

Sodium Killed a researcher

    Some day in 1995. The lab in Jorhat, Assam. A PhD student wanted an ambered glass bottle for storing of his solvent. He found one with something inside it. He did not look at what was inside but straight away went to the washbasin and tried to clean the bottle. When he poured water inside the bottle, a big explosion occurred with some fire. Everything happened instantly but no one was hurt as the lab attendant extinguished the fire with a fire extinguisher. Everyone just shocked what has happened and found that there was some sodium wire inside the bottle and vapour of Tetrahydrofuran solvent. We all thankful to God that nothing big destruction occurred.
    The next morning we all came at 8.30 AM but the student did not appear. When he did not come till 12 pm, the lab attended went to his place upon request of the Head scientist. The student was living alone in a private rental dormitory in front of the research institute. When lab attendant arrived his room he asked the landlord about the student but they did not notice anything about him. Then they were alert too and went to his room together with the lab attendant when they knew that he did not go to the lab that day. The door was hooked from inside. They called him but no answer. Finally, they broke the door and saw the dead body of the student on the bed. Post mortem report revealed the cause of heart failure while sleeping. It was thought that he might get a big shock from the incident in the previous day.  The rest of the day became very sad for all the people of the institute.

       Chemistry: We use sodium in the form of wire to make tetrahydrofuran solvent dry. After the use of all the dry solvents, we usually destroy the remaining sodium metal by using methanol or ethanol which reacts with sodium to make sodium alkoxide. We have to pour slowly methanol in the sodium wire and as the reaction is exothermic, a condenser is used to reflux the methanol.  Normally for drying THF.we should use a transparent bottle not ambered glass so that it is easy to see the blue colour of Na-benzophenone ketyl radical ion. We use a little bit of benzophenone in the THF and reflux the solvent with sodium metal until it appears blue. The blue color indicates the solvent is absolutely dry. Then we keep it like that and when needed we distill some amount from it for reactions.
        The mechanism: Sodium metal reacts with the residual water in the THF solvent and form sodium hydroxide in refluxing condition. When all water reacted with sodium and the solvent gets dry, the sodium metal and the benzophenone form the Sodium benzophenone ketyl radical which is deep blue color species. The reaction scheme is showing the structure of the species below.

                                                 
The Lesson: 
1. We must avoid ambered glass bottles for keeping sodium wire. 
2. We must never leave sodium metal dry and destroy immediately after use. Commercially it kept under kerosene. 

Tuesday, June 16, 2020

Indian Cheers

       One Friday evening in 2001, after coming back from the work to the hostel around 6.45 pm, I was delighted to see the arrangement of a party in the common kitchen. Immediately rushed to my room and took a hot shower. Got fresh, teeth were doubly checked and brushed. I came out of my room with fresh clothes and perfumes. I just forgot any failure or pain in the lab of the day. The mind filled with some pleasure and the face with a sweet smile. Party already started, I joined with a bottle of wine. This nice evening was in Aarhus Denmark. The hostel was full of varieties of students from different countries who were studying at the University. Obviously, the excitement can be imagined from the fact that it was an international party among many young boys and girls. Many students from France, Spain, Italy, Germany, Czech Republic, Greece, Russia, Poland, China, Vietnam, Indonesia, and I was the only one from India. A total of around 40 people were there. Party was ripening at around 11.30 pm. People were a little bubbly and drunk. The conversation was getting louder. Music was on but no one was concentrating on it. Everyone was sitting in the table, eating and drinking. Once someone started from a corner of the table that what they say in France for cheers? Sophie the France girl said 'sante'. Everyone did sante with their own glass and drank a sip whatever they had in their glasses. Sophie then asked Laura what they say in Spain for cheers while toast? She said 'Salud'. Everyone shouted salud with full energy and drank a sip. The chain continued for many countries.....'Alla Salute' or 'Cin Cin Alla Salute' for Italy, 'Prost' for Germany, 'Genbei' for China, 'Barsulang' for Indonesia.and so on. I was thinking what should I say when my turn would come? I don't know any other words except Cheers in India. But I was not feeling comfortable to say Cheers as I was afraid they might laugh and think that we were ruled by British and therefore we still follow them. I started thinking with extra energy to my brain as I was sure that there would be a word for us but it was maybe not coming to my mind. Such a big country with so many languages, why there will be not a small word available for it for this kind of common activity. I was feeling very restless and shy to say cheers. Suddenly I remembered a story once I was going to a tribal village where I saw elderly people were drinking their homemade alcoholic rice beverages in a ritual ceremony and started the drink by saying 'Raiz Dharak'. Dharak in terms of food or drink in our language means to start something. Ha Ha Ha .....I immediately felt relaxed. When my turn came I said 'dharak dharak' for Bharat (India). Everybody at the party drank a sip of their drink by shouting dharak dharak and showing their respect authentically to my country. Oh.....I felt proud of those elderly tribal people .....Heartiest thanks .....