Absolute electronegativity and absolute hardness of Lewis acids and bases

✍ Scribed by Pearson, Ralph G.

• Book ID: 120358146
• Publisher: American Chemical Society
• Year: 1985
• Tongue: English
• Weight: 729 KB
• Volume: 107
• Category: Article
• ISSN: 0002-7863
• DOI: 10.1021/ja00310a009

✦ Synopsis

The relationship of xo, the absolute electronegativity, and 7, the absolute hardness, to chemical bonding in Lewis acid-base complexes is examined. This is done by using semiempirical MO theory in which the same experimental parameters appear. The a priori electronegativity of a Lewis acid or base is shown to be ( I + A ) / 2 . For any two atoms, ions, or molecules, the direction of net electron flow is determined by the difference in xo values. For a specific pair of reactants, the effective value of xo can range from AA for a pure electron acceptor to I , for a pure electron donor. The most common situation will have electron transfer in both directions (u plus B bonding). Then xo will be a weighted mean of I and A for both acid and