Hybridization of Atomic Orbitals PGCC CHM 101 Sinex Illustrating hybridization Shockwave animation of hybridization click here Chime site with atomic and hybrid orbitals click here Now let’s make some bonds! hybrid orbitals – sp, sp2, or sp3 formation of s bond s bond remaining p orbitals from sp or sp2 p bond hinders rotation about the carbon-tocarbon bond Planar molecule (each carbon is trigonal planar) with p cloud above and below the plane formation of p bond Bond formation from hybridization • Single bond end-to-end - sigma bond side-to-side • Double bond – sigma bond + pi bond • Triple bond – sigma bond + pi bond + pi bond How are the two pi bonds in the triple bond oriented? How about the electron density around a carbon-carbon bond? Polar or Non-polar C2H6 C2H4 C2H2 H+ attack? single bond double bond triple bond Spartan 02 What is the hybridization in each carbon atom? 4 2 5 6 3 7 1 sp3 – 2, 5 tetrahedral sp2 – 1, 3, 4 trigonal planar sp – 6, 7 linear What is the hybridization in each carbon atom? 4 3 2 1 Draw the Lewis dot structure – C3H4 Remember to chain the carbon atoms and fill the octet of the center carbon atom in the chain first. You should have come up with one of these structures: H .. H:C:C:::C:H .. H H H .. .. C::C::C .. .. H H Build the molecular model. Allene, H2C=C=CH2 What is the hybridization? The p clouds of the two double bonds are oriented perpendicular to each other. Hence the hydrogens are turned 90o. The is due to the original orientation of the p orbitals on the center carbon atom. Spartan 02