CHEM 130 Lecture Notes - Lecture 9: Antibonding Molecular Orbital, Allyl Group, Electronegativity
Document Summary
It should be clear that in butadiene the double bonds are conjugated here we have four p orbitals. How can we get an isolated p orbital after all, we can"t have half a double bond. Let us look for a moment at allyl bromide (prop-2-enyl bromide or 1- bromoprop-2-ene). Carbon 1 in this compound has got four atoms attached to it (a carbon, two hydrogens, and a bromine atom) so it is tetrahedral (or sp3 hybridized). Bromine is more electronegative than carbon and so the c br bond is polarized towards the bromine. If this bond were to break completely, the bromine would keep both electrons from the. C br bond to become bromide ion, br , leaving behind an organic cation. The end carbon would now only have three groups attached and so it becomes trigonal (sp2 hybridized).
