SUBTLE CONTROL IN SOLUTION AND CRYSTAL STRUCTURES WITH WEAK HYDROGEN BONDS: THE UNUSUAL PROFILE OF DIMETHYL 3, 12-DIOXO-7, 8 DITHIA 4, 11-DIAZABICYCLO[12.2.2]OCTADECA-1(16), 14, 17-TRIENE 5, 10-DICARBOXYLATE (TDA1).