how to find strength of Lewis acid. ...
Answers
Answered by
2
Well, it's definitely true that a Lewis acid will accept a pair of electrons, and a Lewis base will donate a pair of electrons. What is meant by "strength" is basically "how easily" this is done by a particular lewis acid/base. A stronger lewis acid will more easily accept electrons than a weaker one. By "more easily," i mean that accepting electrons will not unduly increase the energy of the molecule (remember that atoms form molecules and eventually compounds to achieve the lowest energy state possible), cause strain in the bonds, etc.
So the ease with which a lewis acid will accept electrons is dependent on electronic and steric factors. The presence of electron-withdrawing groups in the molecule will cause the molecule to have a greater affinity for a donated electron groups (since there's likely to be a partial positive charge present to attract the negatively charged electron pair from the ewis base), while the presence of electron-donating groups in the molecule would tend to increase the lewis basicity of the molecule (and hence decrease its acidity- it ill be more likely to donate a pair of electrons than receive ANOTHER pair).
So the ease with which a lewis acid will accept electrons is dependent on electronic and steric factors. The presence of electron-withdrawing groups in the molecule will cause the molecule to have a greater affinity for a donated electron groups (since there's likely to be a partial positive charge present to attract the negatively charged electron pair from the ewis base), while the presence of electron-donating groups in the molecule would tend to increase the lewis basicity of the molecule (and hence decrease its acidity- it ill be more likely to donate a pair of electrons than receive ANOTHER pair).
Answered by
2
smaller size strong the lewis acid
high +ve charge greater the lewis acidity.
high +ve charge greater the lewis acidity.
Similar questions