21. Basic bonding and steric effects are at times insufficient to explain many structures, properties, and reactivity. 22. The different geometries along the rotation paths can be rationalized in terms of mesomeric and steric effects ." 23. Then the first push-pull diarylaminyls were synthesized and shown to have stabilities depending both on electronic and steric effects . 24. Due to steric effects , second-order Markov effects may also play a role in the growth of some polymer chains. 25. The Simmons Smith reaction is generally subject to steric effects , and thus cyclopropanation usually takes place on the less hindered face. 26. In Figure 3, 1 is favored over 2 due to the large steric effect in 2 from the two phenyl groups. 27. However, the steric effect makes it more difficult for the molecule to achieve the rearrangement transition state and form AD +. 28. 2, 6-Lutidine is weakly nucleophilic, due to the steric effects of the two methyl groups on the ring nitrogen. 29. Similarly to the Hammett ? value, the magnitude of ? will reflect to what extent a reaction is influenced by steric effects : 30. "' Steric effects "'arise from a fact that each atom within a molecule occupies a certain amount of space.
