Experimental Characterization of C鈥揦路路路Y鈥揅 (X = Br, I; Y = F, Cl) Halogen鈥揌alogen Bonds

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• 作者：Dieter Hauchecorne ; Wouter A. Herrebout
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：November 14, 2013
• 年：2013
• 卷：117
• 期：45
• 页码：11548-11557
• 全文大小：352K
• 年卷期：v.117,no.45(November 14, 2013)
• ISSN：1520-5215

文摘

Using FTIR and Raman spectroscopy, we investigated the formation of halogen bonded complexes of the trifluorohalomethanes CF₃Cl, CF₃Br, and CF₃I with the halomethanes CH₃F and CH₃Cl and the haloethanes C₂H₅F and C₂H₅Cl dissolved in liquid krypton. For CF₃Br and CF₃I, evidence was found for the formation of C鈥揦路路路F and C鈥揦路路路Cl halogen bonded 1:1 complexes. Using spectra recorded at different temperatures, we determined the complexation enthalpies for the complexes to be 鈭?.0(3) kJ mol^鈥? for CF₃Br路CH₃F, 鈭?.6(1) kJ mol^鈥? for CF₃I路CH₃F, 鈭?.9(2) kJ mol^鈥? for CF₃Br路CH₃Cl, 鈭?.3(3) kJ mol^鈥? for CF₃I路CH₃Cl, 鈭?.1(1) kJ mol^鈥? for CF₃Br路C₂H₅F, 鈭?.7(2) kJ mol^鈥? for CF₃I路C₂H₅F, 鈭?.5(2) kJ mol^鈥? for CF₃Br路C₂H₅Cl, and 鈭?.8(3) kJ mol^鈥? for CF₃I路C₂H₅Cl. For all halogen bonded complexes with a fluorine-electron donor, a blue shift ranging from +0.6 to +1.5 cm^鈥? was observed for the C鈥揦 stretching mode. The results from the cyrospectroscopic study are compared with ab initio calculations at the MP2/aug-cc-pVDZ(-PP) level.