INFRARED-SPECTRA OF HF COMPLEXES WITH CCL4, CHCL3, AND CH2CL2 IN SOLID ARGON

Hydrogen fluoride complexes with CCl4, CHCl3, and CH2Cl2 were prepared in argon matrices and characterized by infrared spectroscopy. The spectra of CCl4 and HF revealed a strong CCl4-HF complex absorption at 3876 cm-1 with a considerably weaker band at 3904 cm-1 due to the CCl4-FH complex. Only one 1:2 complex, CCl4-HF-HF, was observed at higher HF concentrations and matrix annealings. Similarly, the HF interaction with CH2Cl2 produced two 1:1 complexes and one 1:2 complex. However, the major product absorption at 3901 cm-1 was assigned to the anti-hydrogen-bonded complex, CH2Cl2-FH, while a less intense doublet due to the CH2Cl2-HF complex appeared at 3799 and 3793 cm-1. The IR spectra of CHCl3 and HF were more complicated due to the presence of a third 1:1 complex. The CHCl3-HF complex band at 3860 cm-1 was clearly the strongest product absorption. In addition, the CHCl3-FH complex produced a 3903-cm-1 absorption, while a triplet probably due to the HF-HCCl3 complex was observed at 3893, 3883, and 3875 cm-1. Finally, the acid-base properties of these common solvents were considered.