X-Bonding

Halogen Bonding:Fundamentals and Applications

Angella Mahasi

Novemeber 7th 2014

Earlier in the month, I sat in on a seminar where Dr. Bill Pennington, a professor and Director of Molecular Structure at Clemson Unversity. What he was talking about that day was his research on halogen bonding. He first explained what halogen bonding was, then showed us the halogen bonding periodic table before talking about polyiodides and metapolyiodies and the application of halogen bonding with that.  From what I understood, Halogen bonding is an important bond that is essential to our existence.  After paraphrasing the IUPAC definition  of halogen bonding, he described it to be a non-covalent interaction that involve halogens as "acceptors" of electron density.  This is similar to hydrogen bonding when hydrogen acts as an acceptor of electron density as well.  In other words, halogen bonding is just as strong as hydrogen bonding.  Dr. Pennington then went on to discuss his why he was so interested in halogen bonding. For his research halogen bonding are key to discover different crystal arrangements. The main halogen he discussed was iodine. From what I understood Iodine reacted with other iodine through halogen bonding causing it to have higher boiling points than other halogens such as chlorine and fluorine. Understanding that halogen bonds strengthened a molecule this way opened to door to many other possibilities. During this whole seminar, though the matter that was being discussed was difficult to understand, I could not help but to feed of of Dr. Pennington enthusiasm. Perhaps with a little more chemistry, I could come to appreciate Dr. Pennington's work.  

His credential and publications are listed on this url below:

http://www.clemson.edu/ces/departments/chemistry/people/faculty/pennington.html .