Structure and Bonding – sp 3 orbitals Look at methane, CH 4 We must take a look at the 2s and 2p orbitals of carbon Carbon has two core electrons, and 4 valence Look at the ground state electron configuration
Using the ground state configuration, carbon should only form two bonds Bc there are only two unpaired electrons: This is NOT STABLE! NO OCTET! Does not work!
Structure and Bonding - sp 3 orbitals Second possibility: with energy, promote an electron in 2s to the empty 2p orbital Still not good description! This means carbon would form two types of bonds: 3 bonds with the 2p orbitals and 1 bond with the 2s orbital
Structure and Bonding - sp 3 orbitals Evidence shows that the four bonds in methane are identical We do not use pure s and pure p orbitals, instead we use hybrid of the two types of orbitals
Structure and Bonding – sp 3 orbitals Hybridization of the 2s and three 2p orbitals produced four hybrid orbitals:
Structure and Bonding – sp 3 orbitals Each bond in CH 4 is formed by an overlap of one sp 3 orbital of carbon with a 1s orbital from hydrogen
Structure and Bonding - sp 2 orbitals One 2s orbital and two 2p orbitals form three sp 2 hybrid orbitals, leaving one of the 2p orbitals unhybridized
Structure and Bonding - sp 2 orbitals Lets look at ethene, C 2 H 4