Hoffmann, his poetry, plays, books, and articles, visit his official website. The following biographical sketch is taken from that website:. Roald Hoffmann was born in in Zloczow, Poland. Having survived the war, he came to the U. Since he is at Cornell University, now as the Frank H. In I received my doctorate, as the first Harvard Ph.
Several academic jobs were available, and I was also offered a Junior Fellowship in the Society of Fellows at Harvard. I chose the Junior Fellowship. The three ensuing years in the Society — 65 , gave me the time to switch my interests from theory to applied theory, specifically to organic chemistry. It was EJ. Corey who taught me, by example, what was exciting in organic chemistry. I began to look at all kinds of organic transformations, and so I was prepared when in the Spring of R. Woodward asked me some questions about what subsequently came to be called electrocyclic reactions.
That last year at Harvard was exciting. I was learning organic chemistry at a great pace, and I had gained access to a superior mind. Woodward possessed clarity of thought, powers of concentration, encyclopedic knowledge of chemistry, and an aesthetic sense unparalleled in modern chemistry. He taught me, and I have taught others.
The — 65 period was creative in other ways as well: Our two children, Hillel Jan and Ingrid Helena, were born to Eva and me. In I came to Cornell where I have been ever since. A collegial department, a great university and a lovely community have kept me happy.
I am now the John A. Newman Professor of Physical Science. I have received many of the honors of my profession. My research interests are in the electronic structure of stable and unstable molecules, and of transition states in reactions. I apply a variety of computational methods, semiempirical and nonempirical, as well as qualitative arguments, to problems of structure and reactivity of both organic and inorganic molecules of medium size.
My first major contribution was the development of the extended Huckel method, a molecular orbital scheme which allowed the calculation of the approximate sigma- and pie- electronic structure of molecules, and which gave reasonable predictions of molecular conformations and simple potential surfaces.
These calculations were instrumental in a renaissance of interest in sigma electrons and their properties. My second major contribution was a two-pronged exploration of the electronic structure of transition states and intermediates in organic reactions. In a fruitful collaboration R.
Woodward and I applied simple but powerful arguments of symmetry and bonding to the analysis of concerted reactions. These considerations have been of remarkable predictive value and have stimulated much productive experimental work.
In the second approach I have analyzed, with the aid of various semiempirical methods, the molecular orbitals of most types of reactive intermediates in organic chemistry-carbonium ions, diradicals, methylenes, benzynes, etc. Recently I and my collaborators have been exploring the structure and reactivity of inorganic and organometallic molecules.
Approximate molecular orbital calculations and symmetry-based arguments have been applied by my research group to explore the basic structural features of every kind of inorganic molecule, from complexes of small diatomics to clusters containing several transition metal atoms. A particularly useful theoretical device, the conceptual construction of complex molecules from ML n fragments, has been used by my research group to analyze cluster bonding and the equilibrium geometries and conformational preferences of olefin and polyene metal carbonyl complexes.
A satisfactory understanding of the mode of binding of essentially every ligand to a metal is now available, and a beginning has been made toward understanding organometallic reactivity with the exploration of potential energy surfaces for ethylene insertion, reductive elimination and alkyl migrative insertion reactions. Several new structural types, such as the triple-decker and porphyrin sandwiches, have been predicted, and recently synthesized by others.
On the more inorganic side, we have systematically explored the geometries, polytopal rearrangement and substitution site preferences of five, six, seven and eight coordination, the factors that influence whether certain ligands will bridge or not, the constraints of metal-metal bonding, and the geometry of uranyl and other actinide complexes. I and my coworkers are beginning work on extended solid state structures and the design of novel conducting systems. The technical description above does not communicate what I think is my major contribution.
I am a teacher, and I am proud of it. At Cornell University I have taught primarily undergraduates, and indeed almost every year since have taught first-year general chemistry. I have also taught chemistry courses to non-scientists and graduate courses in bonding theory and quantum mechanics. The information is sometimes updated with an addendum submitted by the Laureate.
In the last decade I and my coworkers have begun to look at the electronic structure of extended systems in one-, two-, and three dimensions.
Frontier orbital arguments find an analogue in this work, in densities of states and their partitioning. We have introduced an especially useful tool, the COOP curve. This is the solid state analogue of an overlap population, showing the way the bond strength depends on electron count.
My group has studied molecules as diverse as the platinocyanides, Chevrel phases, transition metal carbides, displacive transitions in NiAs, MnP and NiP, new metallic forms of carbon, the making and breaking of bonds in the solid state and many other systems. One focus of the solid state work has been on surfaces, especially on the interaction of CH 4 , acetylene and CO with specific metal faces.
Rhodes Professor of Humane Letters. Hoffmann is also well known for his role in the creation of the Woodward-Hoffmann rules. When Robert Burns Woodward synthesized vitamin B 12 , a key reaction in the multistep synthesis proceeded in a way not predicted by Woodward.
This totally unanticipated result and several other previously inexplicable reactions ultimately led to the formulation of the Woodward-Hoffmann rules. These rules permit chemists to predict, for example, the products that form when two compounds are activated by heat compared with the distinct products that form when the same two compounds are activated by light. For his contribution to this work Hoffmann received the Nobel Prize in Chemistry shared with Kenichi Fukui, a chemist working in Japan, who developed a different way of analyzing chemical interactions that could explain the same chemical changes.
His Chemistry Imagined , a unique collaboration with artist Vivian Torrence, reveals the creative and humanistic sparks of molecular science.
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