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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: 21385 on December 28, 2007, 12:28:23 AM

Title: Lewis acid/base
Post by: 21385 on December 28, 2007, 12:28:23 AM
Is IF(3) a lewis acid or base?

The Lewis diagram shows that it has a T-shaped configuration but I don't know how do you classify lewis acid/base for atoms exceeding the octet rule. Thanks
Title: Re: Lewis acid/base
Post by: LQ43 on December 28, 2007, 12:40:01 AM
What is the defn of a Lewis acid / Lewis base?

Would IF3 with its extra electron pairs want to accept or donate electrons?

Title: Re: Lewis acid/base
Post by: 21385 on December 28, 2007, 01:18:43 AM
I don't know, the solution to this answer says that it is a lewis acid but I am not sure if it is a typo or not.  Although it has extra electrons pairs that would make a lewis base, I am not sure whether iodine could use its d-orbitals to take in more pairs, which would it make it a lewis acid.

Title: Re: Lewis acid/base
Post by: AWK on December 28, 2007, 04:56:20 AM
There is no simple answer to this question except geometry.
IF3 is a Lewis base (formally it has free electron pairs), but is is also electron deficient (Lewis acid). As far as I know only relatively stable IF4- salts are known (this means IF3 reacts as Lewis acid).
There is rather little chance to check IF3 basicity since this compound is unstable. You should search a literature or monographs for eventual formation BF3.IF3 but I think its structure will be  IF2+BF4-.