The invention provides compounds of formula I, II, and III as described herein, as well as pharmaceutical compositions comprising the compounds, and synthetic methods and intermediates that are useful for preparing the compounds. In one example, a first control message is sent from a first radio to a second radio, the control message including a data field, the data field containing a short message directed from a user of the first radio to a user of a third radio. The spectrums of the PDP shall be corrected by the filter, so that the PDP can be improved in color purity and color reproducibility.