Knowledge Bank

A magnetic circular dichroism (MCD) study of the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Sigma -\to 3\pi$ transition of the N-H radical isolated in Ar and Xe matrices is reported. The samples are prepared by passing a 1% mixture of $NH3$ in the noble gas through a windowless discharge tube interfaced to the sample chamber of a superconducting solenoid. The MCD spectra are very sharp and intense and exhibit a strong, complex temperature dependence. A detailed study of this temperature dependence permits one to deduce the zero-field-spitting (D) of the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Sigma -$ ground state and the spin-orbit coupling constant $(\zeta )$ in the excited state. A preliminary analysis indicates that D is about 50% higher and $\zeta$ about 30% lower than the corresponding quantities in the gas phase.