The recent renaissance in the field of polyaromatic chemistry has been fueled by remarkable 2D and 3D carbon-rich materials built via the fusion of multiple benzene units. The transformative potential of these molecular architectures in different areas of materials science calls for practical approaches to the construction of precisely shaped and functionalized polyaromatic architectures.
Currently, there are many unanswered questions of how electronic properties evolve from a single molecule of benzene to the infinite 2D structure of graphene, depending on molecular shape and dimensions. The only way to answer these questions is to make well-defined graphene substructures. It is not practical to cut them from graphene. Instead, they have to be made via a “bottom up” approach.
Proposed research will leverage our expertise in alkyne cyclizations for developing new ways to prepare such carbon nanostructures. In particular, we will pursue unusual cyclizations that anneal additional benzene rings at the zigzag edge of polyaromatics.
The expected outcomes are three-fold: a) development of a new synthetic route to odd-alternant polycyclics via the previously unknown “peri” radical cyclizations of alkynes and acenes, b) development of benzannulations at the zigzag edge (“L-region”) of polyaromatics, c) discovery of new conjugated molecules with useful properties for molecular electronics. We will accomplish our objectives by pursuing the following specific aims:
Aim 1. Test the efficiency of traceless directing groups for the SnR3-mediated peri-cyclizations (attack at the peri-positions of acene subunits) and explored the reductive, oxidative and self-terminating workup regimes.
Aim 2. Develop new approaches to expanded analogues of phenalenyl radicals including transition to the 3D spin systems of fused buckybowls.
Aim 3. Design “double” peri-cyclizations where two vinyl radicals converge on the same aromatic core
Aim 4. Test for the possibility of introducing additional rings between the two radical peri-cyclization precursors for the preparation of “double-decker” products.
The new postdoctoral fellow will have an opportunity to learn the art of inventing new chemical reactions by using a combination of experimental and computational methods. He/she will also be involved in mentoring graduates students. The postdoc will receive mentoring in writing manuscripts, proposals and giving research presentations.