| The Team | Projects | Publications | Presentations |
| Funding | For Highschoolers | Lab Alumni | Group Events |
Research projects in the Thamattoor lab are specifically designed to engage undergraduates as partners in the discovery process, and enable them to contribute to the advancement of knowledge in organic chemistry. The synergy of synthetic, mechanistic, analytical, and computational chemistry in their work provides students with a wholesome research experience, and prepares them well for careers beyond Colby. Click on the links below for brief descriptions of some of the projects that are now being investigated by the group.
Carbene Chemistry
Nonplanar Aromatic Hydrocarbons
Strained Cyclic Allenes
Carbene Chemistry
Carbenes (1) are highly reactive species featuring a neutral, divalent carbon that are of much interest to experimental and theoretical chemists alike. Several laboratories, including ours, have used cyclopropane derivatives such as 2 and 3 to photochemically generate these intermediates. A number of substituents may be installed as X and Y in these versatile precursors to generate a wide variety of carbenes. An important driving force for the cheleotropic extrusion of carbenes from such systems is the formation of the stable by-products such as phenanthrene and indan. More recently we discovered that analogous precursors, 4 and 6, can be used to generate vinylidene carbenes 5 and 7 respectively. Advanced techniques such as time-resolved laser flash photolysis and matrix isolation spectroscopy are also employed in these investigations
Nonplanar Aromatic Hydrocarbons
This project aims to synthesize new, severely twisted phenanthrenes (9) by placing large substituents in the 4 and 5 positions. The synthetic approach involves a photochemical cyclization of appropriately substituted stilbenes (8), (available via Wittig reactions) using photochemical procedures developed by Professors Frank Mallory and Tom Katz. Using a somewhat different approach, we are trying to make the triple helicene 11 and semi-fullerene 12 by flash vacuum pyrolysis (FVP) of the precursor 10. The structure, stereochemistry, and spectroscopy of these molecules will be investigated following their preparation. Computational studies are also being pursued to supplement the experimental work.
Strained Cyclic Allenes
Cyclic allenes are ring compounds which feature two adjacent carbon to carbon double bonds. Theoreticians as well as experimentalists have long been fascinated by cyclic molecules incorporating the allenic subunit. Allenic groups, which prefer a linear geometry, can inflict molecular strain on ring systems, and the strain increases with decreasing ring size. This project aims to prepare small- and medium-ring cyclic allenes that are kinetically stabilized by incorporating appropriate substituents. It is anticipated that these molecules will lend themselves to structural characterization, especially by single crystal x-ray diffraction, and thus provide useful fundamental information about their unusual bonding arrangement. The smallest crystalline carboyclic allene known contains a nine-membered ring. Our current efforts are focused on the synthesis of crystalline eight-membered systems such as 13 and 14 shown below.
