Chemformation

The Weekly Newsletter of the MIT Chemistry Department

Volume 11, Number 35
Friday, September 29, 1995

Next Issue: Friday, October 6. Chemformation is published by the Office of the Department Chairman. The deadline for the next issue is Tuesday, October 3. Please convey items of interest (or mailing list changes) to Linda Naida, Room 18-393, Department of Chemistry, MIT, Cambridge, MA 02139, 617/253-4080; 617/258-7500 (fax) or e-mail to lkn@mit.edu. Back issues of Chemformation can be accessed via the Chemistry Department Website.

Visit the Chemistry Department Website at http://web.mit.edu/afs/athena.mit.edu/org/c/chemistry/www/

CONGRATULATIONS TO ACS NATIONAL AWARD WINNERS !!!

Congratulations to two distinguished members of the faculty on becoming recipients of the American Chemical Society National Awards for 1996. Professor Richard Schrock received the Inorganic Chemistry Award sponsored by Monsato Company while Professor Dietmar Seyferth received the Organometallic Chemistry award sponsored by Dow Chemical Company Foundation. Both will receive their awards at the 211th ACS National Meeting in New Orleans, LA in March of 1996.

SEMINAR CALENDAR

T.Y. Shen Distinguished Lecturer in Biological Chemistry: Professor Peter Schultz; Department of Chemistry, University of California at Berkeley; "Lessons from the Immune System: From Catalysis to Materials Science"; Monday, October 2, 1995; 5:00 in Room 10-250; Reception following in 18-490 (Norris Room)
Harvard/MIT Physical Chemistry Seminars: Professor Stuart Rice; Department of Chemistry, University of Chicago; "Dynamic and Static Properties of Quasi-Two-Dimensional Liquids"; Thursday, October 5, 1995; 5:00 at Harvard in MB23; Refreshments in MB23@4:30
George Büchi Visiting Lecturer in Organic Chemistry: Andrew G. Myers; California Institute of Technology; Monday, October 17, 1995; Tuesday, October 18, 1995; 4:00 in Room 6-120

FACULTY RESEARCH TALKS FOR FIRST-YEAR GRADUATE STUDENTS

All talks are scheduled at 7:00 pm

*Mon., Oct.2 (cancelled): Prof. Cummins: New Date, Time TBA
Thurs., Oct. 5: Prof. Bawendi: Amdur Room (6-233)
Wed., Oct. 11: Prof. Liu: Norris Room (18-490); Prof. Davison: Amdur Room (6-233)
Thur., Oct. 12: Prof. ZurLoye: Amdur Room (6-233)
Tue., Oct. 17: Prof. Seyferth: Norris Room (18-490); Prof. Orme-Johnson: Amdur Room (6-233)
Wed., Oct. 18: Prof. Schrock: Norris Room (18-490)
Thurs., Oct 19: Prof. Griffin: Norris Room (18-490)

Students interested in thesis research with faculty who are not presenting a research talk should arrange an appointment during September or October.

*Note - Professor Cummins has been cancelled on October 2, New date and time TBA !!!

Congratulations to Professor Klaus Biemann

The Association of Biomolecular Resource Facilities has recognized Professor Klaus Biemann for his pioneering work in the application of mass spectrometry to the biological sciences. Professor Biemann received the Association's Beckman Award for his seminal contributions to the field at its meeting in July. Professor Biemann's laboratory developed and refined mass spectrometric methods for obtaining detailed structural information on biomolecules, as well as technology to improve the sensitivity of computer algorithms for analyzing data.

Alumni News

Volunteer for the MIT Chemistry Telethon! You are important to the future of MIT. The main goal of the telethon is to upgrade gifts from the most loyal contributors. Your participation will help. Volunteer and receive a free T-shirt, it is a chance to feel good about a job well done, participate in an important MIT program, enjoy a great catered meal and have fun! Sign up by calling Laurie Way at 253-7540 or email her at lway@mit.edu with your name, department, telethon date, on-campus address, daytime phone, and evening phone. The date for the telethon is Thursday, October 19th in the evening. There are also sign-up sheets located around the Department.

Positions Available

Albany Molecular Research, Inc. in Albany New York: has a position open for synthetic organic chemists interested in pursuing a career with their firm. Openings exist in the departments of Molecular Chemistry and their Chemical Development for those with a B.S./M.S. as well as with doctorates.
Johnson and Johnson: Has three openings for Senior Scientists; one in Rheology, one in Analytical Chemistry and one in Surface Microscopy/Spectroscopy. All applicants should possess a Ph.D. degree.
Kings College, London, England: A vacancy exists for a lecturer in the Department of Chemistry beginning in January of 1996. e-mail H.Holland@kcl.ac.uk

Faculty Positions

The University of Arkansas, Fayetteville, Arkansas: has announced an opening for a tenure-track assistant professor of organic chemistry. Applicants should provide evidence of ability to develop a creative and nationally competitive research program and motivation towards excellence in teaching.
The University of Kentucky: Invites applications for a Organic Chemist, no sub-areas are excluded. Criteria is to enjoy research and teaching.
Bingham University in Binghamton, New York: is searching for an analytical chemist to fill a tenure-track position in their Chemistry Department.
The University of California at Davis, Davis, CA: Seeks to fill three tenure-track positions for a Polymer Chemist, an Inorganic Chemistry and for an X-Ray Crystallographer with research interests in the area of biological macromolecules,
The George Washington University, Washington, D.C.: has two openings for positions in Materials/Environmental and Physical Organic Chemistry. Both candidates are expected to develop highly active, funded research programs and have a commitment to excellence in teaching.
The Department of Chemistry at Northern Illinois University, DeKalb, Illinois: invites applications for two positions to open in August of 1996. One is for an assistant professor in physical chemistry and one is for an organic chemist.
The University of Toledo, Toledo, Ohio: has a position open in the Chemistry Department for a biochemist in macromolecular crystallography. Position requires a Ph.D. in chemistry, biochemistry, or crystallography and relevant postdoctoral experience.
University at Buffalo, State University of New York, Buffalo, New York: has an opening for an Assistant Professor of Organic Chemistry for the fall of 1996. The Department has moved into a 47 million dollar building with 7 million dollars worth of new equipment for teaching and research.
San Francisco State University, in San Francisco, CA: is currently seeking candidates for two tenure-track positions, one in biochemistry and the other in organic chemistry. Both positions require a deep commitment to research and teaching.
Yale University, New Haven, CT: is seeking candidates for an Assistant Professorship in Organic Chemistry. All areas of organic chemistry will be considered, including those that interface with biology, medicine, physics and materials science.

Postdoctoral Positions

University of Kansas, Lawrence, Kansas: Has a postdoctoral position open in Chemical Physics/Atomic, Molecular and Optical Physics. The applicant should have either a Ph.D. in either chemistry or physics, and excellent command in both theoretical and computational skills.
The University of Oregon. Eugene, OR: is looking for candidates for postdoctoral positions in the research group of Professor Jeffrey A. Cina, His research focuses on developing a molecular-level understanding of the condenses-phase processes set in motion and measured in ultrafast nonlinear optical experiments.

Chemical Research Safety Note #12

Professor Rick L. Danheiser, Shuang Qiao, Ken Stockman, and the Chemistry Department Safety Committee

Friday, September 29, 1995

Procedures for Working with Liquid Nitrogen

Liquid nitrogen is frequently used in chemical research laboratories for the purpose of cooling. Liquid nitrogen is a valuable coolant because of its low boiling point (bp -196 °C), inexpensive price, and low toxicity. In comparison to liquid air, which was previously used as a popular coolant, liquid nitrogen has the advantage that it does not support combustion.

Handling Liquid Nitrogen: Personal Protection

Cryogenic liquids such as liquid nitrogen can cause very severe burns upon eye or skin contact. Splashes are common when handling liquid nitrogen, and safety goggles must therefore be worn at all times when working with this material. In addition, protective gloves that can easily be removed in the event of a spill should be worn when handling liquid nitrogen (alternatively, potholders may sometimes be more convenient for handling small containers of cryogenic materials). Particular care must be taken to prevent uninsulated vessels containing liquid nitrogen from coming into contact with unprotected parts of the body, since extremely cold materials can become firmly bonded to the skin such that separation is not possible without serious injury.

Contact of the skin with liquid nitrogen can cause severe cryogenic burns; the tissue damage that results is similar to that caused by frostbite or thermal burns. Since small amounts of liquid nitrogen quickly evaporate from the surface of exposed skin, some inexperienced workers may mistakenly underestimate the risk of cryogenic burns when working with this material. In fact, it is not unusual for spills and splashes of liquid nitrogen to become trapped under rings, bracelets, watchbands, or inside gloves, and this can result in serious and painful burns.

Containers for Liquid Nitrogen

The properties of some materials (including metals) change drastically when exposed to cryogenic liquids such as liquid nitrogen. Containers for such liquids must therefore be selected carefully to ensure that they can withstand the temperatures and pressures they may be exposed to. Liquid nitrogen is commonly stored in Dewar flasks which should be taped to minimize the hazard in the event of an implosion.

Cold Traps Cooled with Liquid Nitrogen

A common use of liquid nitrogen is as a coolant for traps incorporated in vacuum lines. Extreme care must be employed when using liquid nitrogen as a cold trap coolant. Systems including liquid nitrogen traps must never be opened to the atmosphere until the trap is removed from the coolant. Oxygen has a higher boiling point (-183 °C) than nitrogen (-196 °C), and will condense out of the atmosphere and collect in a liquid-nitrogen cooled vessel open to the air. Liquid oxygen forms highly explosive mixtures with many organic materials. If you suspect liquid oxygen has condensed in a cold trap, then shield the trap (with an explosion shield, closed hood window, etc.), post a sign indicating the danger, and allow the trap (vented to the atmosphere) to slowly warm to room temperature.

Liquid Nitrogen and Condensed Argon

Argon, a gas commonly employed as an "inert atmosphere" for chemical reactions, distillations, and other laboratory operations, also has a boiling point (-186 °C) which is higher than that of oxygen. Consequently, liquid argon will condense in a reaction vessel under an argon atmosphere which is cooled with liquid nitrogen. This creates an extremely hazardous situation, since if the vessel is then removed from the coolant, the liquid argon will instantly vaporize, expanding in volume by a factor of 847! Even if the vessel is vented (e.g. to an inert gas line), an explosion is very likely due to the rapid increase in pressure in the vessel. Consequently, never cool an apparatus that is under an argon atmosphere using liquid nitrogen.

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