The focus of Dr. Forman's research program involves the synthesis and study of non-natural products that possess unique properties and enhanced reactivity as a result of forced deviations from their ideal geometries. In particular, his research group has been interested in studying the effects of bond angle distortion on the structures and properties of alkenes.
An sp2 hybridized carbon atom is known to have a trigonal planar arrangement of its orbitals with the bond angle of 120o. This group is interested in the synthesis and study of alkenes incorporated into rigid polycyclic systems such that a deviation from planarity is forced.
One type of distortion in alkenes is referred to as pyramidalization and results from a syn-folding of the R group substituents. The degree of folding may be conveniently measured via the pyramidalization angle, Φ, which is defined as the angle between the plane containing one of the doubly bonded carbons and the two substituents (R) attached to it and the extension of the double bond. Representative alkenes possessing pyramidalization of their double bonds include cubene (1) and pentacyclo[4.3.0.02,4.03,8.05,7]non-4,5-ene (2). My research group is currently pursuing an investigation of the synthesis and study of pentacyclo[4.3.0.02,4.03,8.05,7]non-4,5-ene (2).
Figure 1. a.) The σ and π bond of an alkene.
b.) The ideal bond angles of an alkene are 120o.
c.) The σ bond of an alkene can be represented by a line. Note that for clarity, the carbon atoms (C) are not shown.
d.) The π bond of an alkene resulting from the parallel overlap of p-orbitals above and below the σ-framework.
e.) The pyramidalization or syn-folding of a carbon-carbon double bond. The pyramidalization angle, Φ, is shown.
f.) Some representative pyramidalized alkenes.