General Methods. Ultraviolet spectra (UV) were recorded by a Norelco Unicam Model 6P8OOA spectrometer. Wavelengths, L,,, are reported in millimicrons (mpm). Infrared spectra (IR) were recorded by a Perkin-Elmer Model 599 instrument. Mass spectral data were obtained on a Perkin-Elmer RUM-7 or a Kratos MS-80 mass spectrometer.