Knowledge Bank

The line intensities of the 3-0 band of CO and the 1-0 and 2-0 bands of HCl have been obtained using a high resolution infrared spectrometer and low gas pressures to minimize wing and base corrections. The intensity for the 3-0 band of CO was found to be $0.0123\pm 0.0004atm-1cm-2$ at $300\circ K$. The intensities for the $1-0$ and $2-0$ bands of HCl were found to be $131\pm 4$ and $3.68\pm 0.10atm-1cm-2$ at $300\circ K$ respectively. These results and previous data for the $1-0$ and $2-0$ bands of CO and the $3-0$ band of HCl were used in conjunction with theoretical expression derived for the matrix elements of the $1-0,2-0$ and $3-0$ vibration-rotation bands to obtain dipole moment functions for CO and HCl. The derivation of these matrix elements is based on a cubic dipole moment function and on radial wave functions obtained using a quintic power series expansion of the inter-nuclear potential and perturbation theory. The results are given in the form of a rotationless matrix element multiplied by a rotational or Herman-Wallis factor. For CO the dipole moment function was found to be, in Debyes, $M(r)=-0.112+3.10(r-re)-0.31(r-re)2-2.28(r-re)3$. The dipole moment function for HCl was found to be $M(r)=1.09+0.896(r-re)-0.074(r-re)2-0.68(r-re)3$.