Valence Bond Theory: Overlap of Atomic Orbitals

1. 1s 1s F: N2 N: 2p 2s 2p C: C atom 3 s bond; 1 p bond 2s 2p p sp2 C: 2s 2p p sp Valence Bond Theory: Overlap of Atomic Orbitals s bond - overlap of s orbitals H-H + s bond - overlap of s orbital and p orbital H-F 1 s bond - head/head overlap of p orbitals 2 p bonds - sidewise overlap of p orbitals Bonds with hybridization of atomic orbitals: sp3 hybridization C atom: 4 s bonds - overlap of H-s orbitals and sp3 orbitals Of C H: CH4 C: 2s 2p A single sp3 orbital, each with single electron sp3 sp2 hybridization (O also hybridized See next page) H H2CO C O H A single sp2 orbital, each with single electron sp hybridization CO2 C atom: 2 s bonds 2 p bond O C O A single sp orbital, each with single electron

2. N N N2 N: 2s 2p O atom Can form 1 s bond; Can form 1 p bond Has 2 nonbonded pairs Dinitrogren: 2 Models without hybridization – with just p electrons 1 s bond - head/head overlap of p orbitals 2 p bonds - sidewise overlap of p orbitals 2nd sp orbital with sp hybridization – with all valence electrons N: 1st sp orbital one with nonbonded pair N2 1 s bonds 2 p bond 2s 2p N N p sp O atom in H2CO (previous page) • geometry around O is trigonal planar • requires 3 equivalent orbitals from the O • hence, sp2 hybridization O: 2s 2p p sp2