| Abstract
| - Stationary points on the potential energy surface describing thereaction between aluminum and propenehave been optimized at the MP2 and DFT (B3LYP, BLYP, BP86, and PWP86)levels using the 6-31G(d,p)basis set, including ZPE and BSSE corrections. All methods arefound to give very similar geometricalstructures and MP2, MP4, and DFT potential energy surfaces, althoughsome variations exist. An initialaddition complex is formed between Al and C3H6,located 6−15 kcal/mol below the free reactants inenergy.Passing over a transition state barrier of 15−25 kcal/mol, anasymmetric cyclic trans-π-allylaluminumhydrideproduct is formed at energies similar to the addition complex. Asmall barrier separates this product fromthe energetically most stable conformer,cis-π-allylaluminum hydride. Hyperfine couplingconstants (hfcc's)of Al and the protons were computed at all stable structures, using MP2and DFT methods and the 6-311G(d,p), 6-311+G(2df,p), and IGLO-III (PWP86 only) bases. Thehfcc calculations clearly confirm the cis-π-allylaluminum hydride as being the structure observedexperimentally.
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