The invention relates to compounds of structural formula and structural formula :or a pharmaceutically acceptable salt, solvate, clathrate, or prodrug thereof, wherein R, R1, R2, Z, L, and n are defined herein. First and second variable capacitor sections 10 and 20 are connected in parallel with an inductor circuit so as to form a parallel resonant circuit. Each processing component cat be disabled or by-passed to enable or disable the function performed by the component. A single stub matching circuit connects between the common node and an output node such that an open-ended transmission line stub extends from the output node. The gas produced by the chemicals then passes through the sachet and into the package’s atmosphere. Because there is no intermediate focus in the spatial dimension, there are no off-axis aberrations from the anamorphic mirrors, and the field of view may be substantially increased over prior art spectrometers in the spatial dimension.