(b. 1932) Ph.D.,(Chemistry), 1957, Cornell Univ., Ithaca, N.Y.; ACS Award in Pure Chemistry, 1968; Texas Instrument Founders Prize, 1974; National Academy of Sciences, 1974; ACS Arthur C. Cope Award, 1978; Havinga Foundation Medal, 1982; Mobil Corporation Patent of the Year Award, 1992; ComputerWorld Smithsonian Institution Award for Education, 1995.
Synthesis of Molecules of Theoretical Interest
We developed special techniques for the synthesis (photochemical and thermal) characterization of reactive molecules in an argon matrix at 4-10K. Recent successes are shown in Figure 1 and Figure 2. Some current targets appear in Figure 3. Synthesis of molecular forms of pure carbon pose particular challenges. Cyclic-C6 should have an aromatic, six-electron in-plane system as well as the traditional, benzene p-system. The soccer ball (spherical C-60) will be the first molecular form of carbon stable at room temperature .
Reaction Mechanisms
Our success in characterization of cycloheptatetraene led to detailed investigations of the mechanism of arylmethylene rearrangements and these in turn led us to the investigation of the mechanism by which carbon atoms are delivered from high defect carbon surfaces to organic molecules. Other mechanism problems of current interest involve isoacenotropones, trans-cyclo-hexenes, and dehydroaromatics. Isotopic labeling [2]H, [13]C, [18C] plays a major role in our studies of rearrangement mechanisms.
Bio-Organic Chemistry
We are currently active in three areas of bio-organic chemistry. DNA-small molecule binding, proximity labeling, and chemical communication. Our long range goal in the DNA chemistry is a molecular -level understanding of the binding of small molecules which will permit the design and synthesis of a non-natural anti-tumor antibiotic. Our major success in this area has been the synthesis and evaluation of a bis-psoralen (Figure 4) which is active against squamous cell carcinoma. Proximity labeling is a new method developed in our group for establishing proximity between macromolecules of biological importance (two proteins on a membrane for example) and for probing proximity between different regions of the same macromolecule. The system consists of an anchor (covalent bond to the macromolecule), a tether which permits a useful search radius, and a photo-activated group which will react only with itself. Our chemical communication research has focused on insect pheromones. Recently we used chiral mimics of achiral pheromones to probe neurophysiological aspects of perception, and we have isolated, characterized, and synthesized the pheromones of Heliothis zea and Heliothis Virescens, the two most economically damaging crop insects worldwide. Our current work is focused on human pheromones.
Analytical Chemistry
As our microtechniques for identification and characterization become better we are turning to the isolation and characterization of lipids which are important as hormones and in the immune system. We can analyze lipids at the picogram (10[-12]level, and we have characterized insect pheromones when only a few nanograms (10[-9]g) were available.
Polymer Chemistry
In polymer chemistry, we design and synthesize novel materials and demonstrate radically new methods. We are interested in the linear polyacenes as possible superconductors and ferromagnetic organics. The molecular soccer ball (spherical C-60_ is a special molecular, conducting system. The iso-acenotropones, which we discovered, find applications as conducting systems and in the shaping of polymers. These shape-selective cavities are used in chromatography and offer special opportunities in synthesis of shape-selective organic catalysts.
[ Department * Faculty* Current Organic Research* Chapman Biography* Organic Research Interests ]
Last Revision: 08/23/95 // burns@chem.ucla.edu
