Computational Studies of Halogen Bonding Cooperativity: Past, Present, and Future

Friday, October 28, 2011
Hall 1-2 (San Jose Convention Center)
Sarah Lopez, BS , Chemistry , DePaul University , Chicago, IL
Ruben Parra, PhD , Chemistry, DePaul University, Chicago, IL
Computational work is an excellent tool to aid in studies. To give a better appreciation of its capabilities I will begin with a brief overview of the history of computational chemistry in the United States. Incorporated into this rich history is the evolution of technology, theory, and the roles each played in the advancement of this field.  As a result, I hope to impress upon the readers the valuable contributions computational work provides today in spite of the difficulties it faced as novel area of study. This topic was also explored using the results of computational research and other primary resources in literature such as journal articles describing related studies. Specifically, the contributions of computational work to the novel field of halogen bonding will be examined using an actual system, of hydrogen cyanide chains and its halogenated counterparts, (XCN)n where X is F, Cl,  Br, and I and n=1,2,4,6.   The contributions of halogen bonding to biology were likely ignored because of the few known crystal structures of halogen containing biological molecules. Thus, a lot of the characteristics of halogen bonding have been discovered through computational studies. The system selected for study is also relevant to this work because there has been controversy over the type of interactions pertinent to hydrogen and halogen bonding. Cooperativity is an important feature of halogen and hydrogen bonding as demonstrated in the following results and analysis. Therefore, disregarding cooperative effects can bias information reported, a serious consequence which may be overlooked by other researchers!