ROTATIONALLY RESOLVED MAGNETIC VIBRATIONAL CIRCULAR DICHROISM SPECTRA OF NO

Author Institution: Department of Chemistry, University of Illinois at ChicagoWe have measured the magnetic vibrational circular dichroism (MVCD) spectrum of NO at $0.5 cm^{-1}$ resolution using an FTIR spectrometer with a superconducting magnet operated at 8T. These spectra were so intense that saturation effects were evident. The MVCD of individual rotational bands could be interpreted in large part as psuedo-A terms arising from coupling of the spin-orbit split components of the $^{2}\Pi$ ground term. In the P branch these components can be resolved, and the B term associated with the stronger absorbing $^{2}\Pi_{3/2}$ lines were positive and those with the weaker $^{2}\Pi_{1/2}$ lines were about the same intensity but negative. The unresolved O branch has a negative B term. The ease of observation of the NO MVCD is consistent with earlier observations of Zeeman modulated absorption spectra of radicals including NO. Actual signal size increases by an order of magnitude in going from $2 cm^{-1}$ to $0.5 cm^{-1}$ resolution. Attainment of the higher resolution required a modification of our FTIR system to create an artificial center burst on the polarization modulated signa