  Until now the known sources in the Galactic center with sufficiently smooth
spectra and of sufficient brightness to be suitable for high resolution
infrared absorption spectroscopy of interstellar gas occupied a narrow range of
longitudes, from the central cluster of hot stars to approximately 30 pc east
of the center. In order to more fully characterize the gas within the r ~ 180
pc central molecular zone it is necessary to find additional such sources that
cover a much wider longitudinal range. We are in the process of identifying
luminous dust-embedded objects suitable for spectroscopy within 1.2 deg in
longitude and 0.1 deg in latitude of Sgr A* using the Spitzer GLIMPSE and the
2MASS catalogues. Here we present spectra of H3+ and CO towards two such
objects, one located 140 pc west of Sgr A*, and the other located on a line of
sight to the Sgr B molecular cloud complex 85 pc to the east of Sgr A*. The
sightline to the west passes through two dense clouds of unusually high
negative velocities and also appears to sample a portion of the expanding
molecular ring. The spectra toward Sgr B reveal at least ten absorption
components covering over 200 km/s and by far the largest equivalent width ever
observed in an interstellar H3+line; they appear to provide the first
near-infrared view into that hotbed of star formation.
