Electric Field Effect on Condensed-Phase Molecular Systems. VI. Field-Driven Orientation of Hydrogen Chloride in an Argon Matrix

Abstract

The orientation state of hydrogen chloride (HCl) molecules in a solid argon matrix was reversibly controlled by applying an external electric field of up to 4×10**8 V·m–1 using the ice film capacitor method. The rovibrational transitions of the field-oriented HCl were measured by reflection absorption infrared spectroscopy with p-polarized light. Upon application of the external field, free rotation of HCl inside the matrix gradually changed to a pendular state and then to harmonic liberation in the Stark potential well. Further increase in the field strength increased the degree of dipole alignment along the field direction, approaching an asymptotically perfect orientation of the molecules with an average tilt angle of <30° at a field strength above 1×10**8 V·m–1.