Knowledge Bank

In order to determine the structure and force field of silyl chloride, the infrared spectra of several isotopomers were studied. After monoisotopic $D3Si35Cl$ (previous communication), we report here on the analysis of the monoisotopic $H3Si37Cl$ species. Here too, the two fundamental bands $\nu 3(543.968cm-1)$ and $\nu 6(663.736cm-1)$ are linked by a Coriolis resonance but its effects are less important than for $D3SiCl$ and especially than for the two nearly degenerate fundamental bands $\nu 2(947.982cm-1)$ and $v5(950.657cm-1)$. The 'normal' ground state constants $B0,DJ0,DJK0,HJ0,HJK0$, and $DKJ0$ were deduced from more than 6000 GSCD. As for the constants $An$ and $DK0$, they were obtained by the same method as for $D3Si35Cl$. Calibration errors were detected and corrected by checking the closed loop between $\nu 6,(2\nu 6)0$ and $(2\nu 6)0-\nu 6$. The values obtained are $A0=2.84564cm-1$ and $D0=2.54\times 10-6cm-1$ (provisional values). Upper state energies were also determined for $\nu 3,\nu 6,\nu 5,(2\nu 6)\pm 2,(2\nu 6)0,2\nu 3$, and $\nu 3+\nu 6$. Some interesting features of the hot bands $\nu 3+\nu 6-\nu 3$ and $\nu 3+\nu 6-\nu 6$ will also be reported.