TRANS-4,4'-DIPHENYLSTILBENE

4,4'-DIPYRIDYL DISULFIDE

4',5'-DIBROMOFLUORESCEIN

4,5-DICHLORO-2-(2,4-DICHLOROPHENYL)-2,3-DIHYDROPYRIDAZIN-3-ONE

4,5-DICHLORO-2-(4-METHYLBENZYL)-2,3-DIHYDROPYRIDAZIN-3-ONE

4,5-DICHLORO-2,8-DIMETHYLQUINOLINE

4,5-DICHLORO-2-METHYLPYRIDAZIN-3-ONE

4,5-DICHLOROPHTHALIC ACID