MIT Reports to the President 1997-98
In the 1997-98 academic year, the Chemistry Department continued its strong program in research and undergraduate and graduate education. Associated with the department currently are 193 graduate students, 88 postdoctoral researchers, and 125 undergraduate chemistry majors.
As of July 1, 1998, the Chemistry Department Faculty comprises 27 full-time faculty members, including 5 Assistant, 1 Associate, and 21 Full Professors. New faculty appointments in the past year include Peter Seeberger in January, 1998 and Jianshu Cao and Andrei Tokmakoff on July 1 (all as Assistant Professors). In July 1997, Daniel Nocera, formerly Professor of Chemistry at Michigan State University, joined the Department as a Full Professor. Departures from the faculty during the past year include Professor William Orme-Johnson who retired in March and Jamie Williamson who left the department to move to the Scripps Research Institute in January, 1998. In addition, the appointment of Assistant Professor Scott Virgil ended in June, 1998.
FACULTY AWARDS AND HONORS
INFRASTRUCTURE DEVELOPMENTS
The MIT Chemistry 2000 campaign, helping to finance the renovation of 90,000 square feet of laboratory space, is almost complete more than a year ahead of schedule. Generous gifts and pledges from department alumni/ae this year have brought us to within the last $300,000 of the external funding target. These campaign resources (including a challenge grant from Visiting Committee Chair Richard Simmons), combined with department and Institute commitments, will enable $15 million of reconstruction.
To date, renovations begun in early 1997 have been completed to house the Department of Chemistry Instrumentation Facilities (DCIF) in the subbasement of the Dreyfus Building (Building 18), the laboratories of Professor Daniel Nocera, who joined the faculty in the summer of 1997, and the newly consolidated Chemistry Education Office, including undergraduate and graduate student lounges. In July of 1998, renovations will be completed to create state-of-the-art laser labs for Professor Bawendi and a laboratory to house a new experiment for Professor Ceyer. Also nearing completion is the design phase for the laser labs of Professors Nelson, Field, Steinfeld, Nocera, and Tokmakoff, the last being a new appointment effective July 1998, for the wet labs of Professors Schrock and Cummins, for the new Departmental X-ray Crystallography Facility, and for relocated shop support facilities. Construction on these projects will begin in August of 1998 and be completed on a rolling basis over the first and second quarters of 1999. With the exception of the DCIF and the Bawendi Laser labs which are located in Building 18, all of these projects are housed in Chemistry's space in the main group, Buildings 2, 4 and 6. During this past year, a separate team of architects and engineers began to plan for renovations in the Dreyfus Building. During the course of these activities, the need for substantial increases in budget was revealed, resulting from legally mandated building code changes, highly deficient infrastructure, and a variety of safety considerations in both the main group space and building 18. These building code and safety changes are mandated by regulatory authorities and are triggered by the scope of the proposed renovations. We have been advised by the design team that, even if we were drastically to cut back on the scope of the renovations to that of a purely "cosmetic" level, the price of doing even that minimal amount of work would, together with the square footage involved, force us to bring the building into compliance with codes. In simpler terms, if we do any renovations at all, we must do the full renovations. With the scope of the renovations as envisioned and justified in Campaign Chemistry 2000, we are can no longer postpone such action. Whether mandated or not, the only prudent and acceptable course of action to take following disclosure of these infrastructure shortcomings is to correct them, at least to the level required by law, if not further. By its very nature, research in the chemical sciences involves significant hazards and the use of hazardous substances. To provide anything less than the safest possible facilities to our students, postdoctoral research associates, and faculty would be unacceptable and place the Institute in a position of serious moral and legal risk.
EDUCATION
In the Fall of 1997, 35 students entered the graduate program of the Chemistry Department and from September, 1997 to June, 1998 the Department awarded 9 M.S. and 44 Ph.D degrees. In December we opened our new Chemistry Education Headquarters in Building 2, combining two previously-separated offices, the Undergraduate Education Office and the Chemistry Graduate Office. Included in the new Chemistry Education Headquarters are the offices of Dr. Miriam Diamond, Coordinator of Chemistry Education, and Ms. Susan Brighton, Graduate Administrator, and their staff, as well as new Undergraduate and Graduate Student Common Rooms. Also opening this past academic year was a new Computational Chemistry Classroom in Building 6.
The Committee on the Chemistry Curriculum is continuing their review of our undergraduate educational program and this past year saw the introduction of several new courses as a result of their evaluation of the chemistry curriculum. To encourage undergraduate research, a new optional undergraduate thesis was introduced (course 5.ThU) and three seniors submitted theses at the end of the spring semester. An exciting new "active-learning" style course (5.21, "Design and Synthesis") was introduced this spring and taught by Professors Danheiser, Stubbe, and Tidor. In order to provide first-year students with an opportunity for "hands-on" experience in laboratory chemistry, a new IAP course on "Chemistry Labortory Techniques" (Chemistry 5.30) was introduced with great success.
In the area of graduate student education, we continued to expand our intensive training program for Graduate Teaching Assistants and introduced mid-semester "tune-up" sessions on teaching technique. Our academic orientation program for new graduate students was expanded to include a workshop on scientific ethics. In the fall, we held the first of an annual series of workshop/conferences on "Careers for Chemistry Ph.Ds"; the topic of the 1997 conference was "Careers in Education at Principally Undergraduate Institutions".
At the Senior Recognition Dinner in May, the recipients of the 1998 Undergraduate Chemistry Awards were announced:
The Department of Chemistry Outreach Program, created in 1988, continues to be one of the most successful programs of its kind in the country. Currently our graduate students visit over 50 schools each year (including ca. 10 inner-city schools), performing a program of lectures and demonstrations before more than 3,000 high school students.
RESEARCH HIGHLIGHTS
Professor Moungi Bawendi: The Bawendi group has built a system for single molecule fluorescence spectroscopy and applied it to study single quantum dots of CdSe under a variety of conditions, including under applied electric fields. They found that the dots have large enough polarizabilities that potential applications in optoelectronics may be feasable and they have also developed a synthetic methodology for highly fluorescent quantum dots where the emitted light can be tuned throughout the visible by changing the size of the dots.
Professor Sylvia Ceyer: Both surface-bound H atoms and bulk H atoms, upon emerging from the bulk of Ni metal to the surface, are demonstrated to react with C2H2 adsorbed on Ni(111) and to have unique product distributions. This observation is in stark contrast to the unreactivity of surface-bound H and the singular reactivity of bulk H with C2H4, but is consistent with the need for the H atom to have a co-planar approach to the p orbitals of the unsaturated hydrocarbon for reaction to occur. Both bulk H and surface-bound H react with C2H2 to produce adsorbed ethylidyne, CCH3, while only bulk H hydrogenates C2H2 to gas phase ethylene and ethane, the products of interest in acetylene hydrogenation catalysis for the purification of ethylene streams. These results demonstrate that the distinctive reactivities of surface-bound H and bulk H arise from both their distinct energies and directions of approach to the adsorbed unsaturated hydrocarbon.
Professor Robert Field: The Field group is involved in collaboration with scientists in China, France, Switzerland, Canada, and several universities and an Air Force Laboratory in the USA, because his collaborators have functioning laboratories. At MIT they have developed some powerful pattern recognition techniques (Extended Cross Correlation, XCC, and Extended Auto-Correlation, XAC) that are capable of extracting an unknown number of a priori unknown patterns that are repeated in multiple spectra. The XCC method was used to observe the first example of "local bender" behavior in the dispersed fluorescence spectrum of the acetylene molecule. Information extracted from spectra about the structure and dynamics of local benders, unlike normal modes, should be transportable among all molecules that have a similar functional group. This local bender motion lies along the minimum energy isomerization path from acetylene to vinylidene. This brings the goal of actually observing the spectral signature of bond breaking isomerization, a goal I articulated almost 20 years ago as the cornerstone of his research, within their grasp. They have also built a new apparatus designed for the study of triplet states of small polyatomic molecules (e.g. acetylene). From the initial spectra recorded with this apparatus, they have been able to demonstrate that InterSystem Crossing (ISC) in acetylene follows a "gateway mediated" rather than a statistical mechanism. The reason they have been able to accomplish this is the sensitive Auger-effect detection scheme for detecting exclusively triplet states with electronic excitation energy above a specifiable value set by the work function of the "Auger detector". Another new apparatus, designed to measure the multipole moments of molecular cations by millimeter-wave spectroscopy of core-nonpenetrating Rydberg states, is ready to record its first spectra.
Professor John Essigmann: The Essigmann group completed genetic analysis of three oxidized cytosines and found that two of these bases are potently mutagenic. Moreover, they have the mutagenic specificity to explain GC to AT transition mutations. This transition is the most frequent spontaneous mutation observed in aerobic organisms, and they completed total synthesis of the first psoralen-thymine crosslink. This product is being used for studies of crosslink repair.
Professor Alex Klibanov: The Klibanov group has discovered the possibility of correct protein refolding/reoxidation in a nonaqueous solvent, glycerol. Moreover, the refolding yield in glycerol, as well as in various aqueous-organic (predominately organic) mixtures, but not in water, can be markedly enhanced by common salts, Parallel NMR and CD studies have given insights into the structure of proteins dissolved in such nonaqueous medial.
Professor Stephen Lippard: The Lippard group has demonstrated loss of telomeres in cells treated with cisplatin. and modelled DNA methyl phosphotriester repair as well as modelled the centers in methane monooxygenase and ribonucleotide reductase.
Professor Peter Seeberger: The Seeberger laboratory has been concerned with the development of novel
glycosylation reactions and their application to the preparation of biologically active oligosaccharides and glycoconjugates in solution and on a solid support. Particular progress has been made with the synthesis of carbohydrate based vaccines against tropical diseases and cancer as well as novel drug targeting devices.
Professor Robert Silbey: Optical transitions in molecules are very sensitive to the environment of the molecule. In collaboration with the experimental group of Professor Haarer (Bayreuth University, Germany), they compared the long time changes in optical line shape for chromophores in proteins and in organic glasses. The group found that these can be explained by the dynamics of the side chains in the glasses and proteins, while the short time spectral diffusion is explained by the collective backbone dynamics. The differences between proteins and glasses is attributed to the amount of disorder and organization in their respective energy landscapes.
Professor Jeffrey Steinfeld: An IntraCavity laser Absorption Spectrometer has recently been installed in Prof. Steinfeld's laboratory. This instrument is especially suitable for studies of atmospheric trace species, since it provides sensitivity equivalent to a path length of hundreds of km through the atmosphere, but in a controlled laboratory environment in which the pressure, temperature, and composition of the sample may be specified and varied at will by the investigator. Intensity and pressure-broadened linewidth measurements are currently under way on the atmospheric oxygen bands, water vapor, water dimer, and water complexes with atmospheric trace molecules.
Professor Larry Stern: Highlights of research in the Stern Laboratory for 1997-1998 include the demonstration of T-cell activation by MHC dimers and its dependence on the relative orientation of MHC molecules within the dimer, showing that activation requires a particular molecular complex, and discovery of a large conformational change that accompanies peptide binding to class II MHC proteins.
Professor Timothy Swager: The Swager group is actively involved in the design of novel chemical sensors, liquid crystals, and functional supramolecular assemblies. Highlights from the last year include the demonstration of a new highly sensitive sensory material for the detection of TNT, a widely used explosive. This approach involved the synthesis of a new class of conjugated polymers with rigid three-dimensional structures create a porous "honeycomb" type of structure. These porous materials behave as a sponge for electron poor molecules such as TNT and also provide unique stability as well as very bright fluorescence in the solid state.
In the area of supramolecular assemblies, novel procedures utilizing Langmuir-Blodgett techniques have been developed for the organization rigid-rod electronic polymers into nanoscopic fibrils and grids. The nanoscopic grids, which could not be synthesized by conventional methods, and are potential candidates for separating and discriminating different biological molecules.
Professor Bruce Tidor: A theory has been developed for determining optimum electrostatic charge distributions complementary given protein receptors. These optima provide the most favorable balance of ligand desolvation penalty and favorable interactions formed in the complex. This development has important implications for rational ligand design.
More information about the Deparment of Chemistry can be found on the World Wide Web at the following URL:http://web.mit.edu/chemistry/www/
Rick L. Danheiser, Stephen J. Lippard