Not all tertiary haloalkanes undergo SN1 reactions readily. For example, the bicyclic com-pound shown below is very unreactive under SN1 conditions. What feature of this mol-ecule is responsible for such lack of reactivity? You will find it helpful to examine a modelof this compound.
Hybridization of Atomic Orbitals Linus Pauling 1935 Hybridization (combined) Atomic Orbitals different atomic orbitals can combine to give new hybrid orbitals These hybrid orbitals reflect the geometry of the molecule The problem comes from not knowing which molecules hybridize and which ones don’t Predicting Hybridization of Atomic Orbitals Difficult to predict Rules 1. Determine the geometry of the regions of high electron density 2. Assign the set of hybridized orbitals that corresponds to the geometry Sp linear, 180° 2 Sp trigonal, 120° 3 Sp tetrahedral, 109.5° 3 Sp d trigonal bipyramidal, 120°, 90° 3 2 Sp d octahedral, 90° Only three possible hybridization modes for Carbon Sp, Sp , Sp2 3 Geometry of Hybridization of Orbitals 180° Sp Linear (180°) Sp 120° Sp 2 Sp Trigonal planar (120°) flat 3 Sp 109.5° Tetrahedral (109.5°) This is the most common type of Carbon found 90° 3 Sp d Trigonal bipyramidal 120° (120°, 90°) Sp d 2 90° Octahedral (90°) 90° *Black outline = flat region Red outline = vertical region Hybridization of Carbon Structure of carbon and methane Structure of ground carbon: C: 1s , 2s , 2Px, 2Py