The invention provides a compound of formula ; or a salt or solvate thereof, wherein: R1 is hydrogen or C1-4 alkyl; R2 and R4 are each independently selected from C1-4 alkyl, 11CC1-4 alkyl, and 18F\u2014C1-4 fluoroalkyl provided that at least one of R2 and R4 is 11CC1-4 alkyl or 18F\u2014C1-4 fluoroalkyl; and R3 is halo. The method includes multidirectional deformation of an ingot to form a mill form having a preferred average grain size of about 100 microns or less andor a texture substantially void of textural bands. Third and fourth modulators modulate L other information bit streams to be transmitted through the second transmission antenna group and output third and fourth symbol streams. Each set of session management modules includes a plurality of modules, and each subscriber is assigned to one set of modules with one of the modules as a primary and another as a secondary or backup. The instructions cause the programmable state machine to define operation of the serial IO port according to a standard or other predetermined set of serial IO communication parameters.