Here are the essential concepts you must grasp in order to answer the question correctly.
Basicity in Organic Chemistry
Basicity refers to the ability of a compound to accept protons (H+ ions). In organic chemistry, the strength of a base is influenced by the availability of its lone pair of electrons to bond with protons. Stronger bases have more available electron density, which allows them to more readily accept protons.
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Steric Hindrance
Steric hindrance occurs when the spatial arrangement of atoms in a molecule prevents certain interactions, such as protonation. In the case of N,N,2,6-tetramethylaniline, the presence of bulky methyl groups at the 2 and 6 positions creates a more favorable environment for the nitrogen's lone pair to interact with protons, enhancing its basicity compared to N,N-dimethylaniline, which has less steric bulk.
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Electron-Donating Groups
Electron-donating groups, such as alkyl groups, increase the electron density on the nitrogen atom in amines, enhancing their basicity. In N,N,2,6-tetramethylaniline, the four methyl groups significantly increase the electron density on the nitrogen, making it a stronger base than N,N-dimethylaniline, which has only two methyl groups contributing to electron donation.
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