MAGNETO-IR SPECTRA OF MATRIX-ISOLATED NiH AND $NiH_{2}$ MOLECULES AND THEORETICAL CALCULATIONS OF THE LOWEST ELECTRONIC STATES OF $NiH_{2}$

Author Institution: Department of Chemistry and Quantum Theory Project, University of FloridaTwo $\Omega=3/2 \leftarrow 5/2$ transitions ($923,2560 cm^{-1}$) were observed for NiH in solid argon krypton at 4 K; both were shifted and broadened by magnatic fields of up to 4 T. Brands in the $1300-2000 cm^{-1}$ were attributed to the stretching frequencies of $NiH_{2}$ ($NiD_{2}$, Ni HD) establishing it as a strongly bent molecule in its gorund state. Calculations on $NiH_{2}$ indicate a stable bent ($89.9^{\circ}$ and $R(NiH)=1482$\AA) singlet lower state nearly degenerate with respect to the triplet dissociation products but with a large intervening barrier. Calculated vibrational frequencies support the observed assignment